Add spaceless tag

Format changelog attribution to include one name only

.gitignore

@@ -5,6 +5,5 @@ pkg
 *.rbc
 .rvmrc
 .ruby-version
-*.bundle
-/tmp
 Gemfile.lock
+.bundle

.rubocop.yml

@@ -0,0 +1,123 @@
+inherit_from: ./.rubocop_todo.yml
+
+AllCops:
+  Exclude:
+    - 'performance/shopify/*'
+    - 'pkg/**'
+
+Metrics/BlockNesting:
+  Max: 3
+  Exclude:
+    - 'lib/liquid/block_body.rb'
+
+Metrics/ModuleLength:
+  Enabled: false
+
+Lint/AssignmentInCondition:
+  Enabled: false
+
+Lint/AmbiguousOperator:
+  Enabled: false
+
+Lint/AmbiguousRegexpLiteral:
+  Enabled: false
+
+Lint/ParenthesesAsGroupedExpression:
+  Enabled: false
+
+Lint/UnusedBlockArgument:
+  Enabled: false
+
+Lint/EndAlignment:
+  AlignWith: variable
+
+Lint/UnusedMethodArgument:
+  Enabled: false
+
+Style/SingleLineBlockParams:
+  Enabled: false
+
+Style/DoubleNegation:
+  Enabled: false
+
+Style/StringLiteralsInInterpolation:
+  Enabled: false
+
+Style/AndOr:
+  Enabled: false
+
+Style/SignalException:
+  Enabled: false
+
+Style/StringLiterals:
+  Enabled: false
+
+Style/BracesAroundHashParameters:
+  Enabled: false
+
+Style/NumericLiterals:
+  Enabled: false
+
+Style/SpaceInsideBrackets:
+  Enabled: false
+
+Style/SpaceBeforeBlockBraces:
+  Enabled: false
+
+Style/Documentation:
+  Enabled: false
+
+Style/ClassAndModuleChildren:
+  Enabled: false
+
+Style/TrailingComma:
+  Enabled: false
+
+Style/IndentHash:
+  EnforcedStyle: consistent
+
+Style/FormatString:
+  Enabled: false
+
+Style/AlignParameters:
+  EnforcedStyle: with_fixed_indentation
+
+Style/MultilineOperationIndentation:
+  EnforcedStyle: indented
+
+Style/IfUnlessModifier:
+  Enabled: false
+
+Style/RaiseArgs:
+  Enabled: false
+
+Style/DeprecatedHashMethods:
+  Enabled: false
+
+Style/RegexpLiteral:
+  Enabled: false
+
+Style/SymbolLiteral:
+  Enabled: false
+
+Performance/Count:
+  Enabled: false
+
+Style/ConstantName:
+  Enabled: false
+
+Style/CaseIndentation:
+  Enabled: false
+
+Style/ClassVars:
+  Enabled: false
+
+Style/PerlBackrefs:
+  Enabled: false
+
+Style/WordArray:
+  Enabled: false
+
+Style/ModuleLength:
+  Exclude:
+    - lib/liquid/standardfilters.rb

.rubocop_todo.yml

@@ -0,0 +1,82 @@
+# This configuration was generated by `rubocop --auto-gen-config`
+# on 2015-06-08 18:16:16 +0000 using RuboCop version 0.32.0.
+# The point is for the user to remove these configuration records
+# one by one as the offenses are removed from the code base.
+# Note that changes in the inspected code, or installation of new
+# versions of RuboCop, may require this file to be generated again.
+
+# Offense count: 5
+Lint/NestedMethodDefinition:
+  Enabled: false
+
+# Offense count: 53
+Metrics/AbcSize:
+  Max: 58
+
+# Offense count: 16
+# Configuration parameters: CountComments.
+Metrics/ClassLength:
+  Max: 314
+
+# Offense count: 12
+Metrics/CyclomaticComplexity:
+  Max: 15
+
+# Offense count: 553
+# Configuration parameters: AllowURI, URISchemes.
+Metrics/LineLength:
+  Max: 294
+
+# Offense count: 77
+# Configuration parameters: CountComments.
+Metrics/MethodLength:
+  Max: 46
+
+# Offense count: 1
+# Configuration parameters: CountComments.
+Metrics/ModuleLength:
+  Max: 235
+
+# Offense count: 6
+Metrics/PerceivedComplexity:
+  Max: 13
+
+# Offense count: 1
+Style/AccessorMethodName:
+  Enabled: false
+
+# Offense count: 1
+# Cop supports --auto-correct.
+Style/ClosingParenthesisIndentation:
+  Enabled: false
+
+# Offense count: 3
+# Configuration parameters: MinBodyLength.
+Style/GuardClause:
+  Enabled: false
+
+# Offense count: 4
+# Configuration parameters: EnforcedStyle, SupportedStyles.
+Style/MethodName:
+  Enabled: false
+
+# Offense count: 1
+Style/MultilineBlockChain:
+  Enabled: false
+
+# Offense count: 2
+# Configuration parameters: EnforcedStyle, MinBodyLength, SupportedStyles.
+Style/Next:
+  Enabled: false
+
+# Offense count: 7
+# Cop supports --auto-correct.
+# Configuration parameters: AllowAsExpressionSeparator.
+Style/Semicolon:
+  Enabled: false
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: MaxLineLength.
+Style/WhileUntilModifier:
+  Enabled: false

.travis.yml

@@ -1,16 +1,20 @@
+language: ruby
+
 rvm:
-  - 1.9.3
-  - 2.0.0
-  - 2.1.0
-  - jruby-19mode
+  - 2.0
+  - 2.1
+  - 2.2
+  - ruby-head
   - jruby-head
-  - rbx-19mode
+  - rbx-2
+
+sudo: false
+
 matrix:
   allow_failures:
-    - rvm: rbx-19mode
     - rvm: jruby-head
 
-script: "rake test"
+script: "bundle exec rake"
 
 notifications:
   disable: true

Gemfile

@@ -1,3 +1,14 @@
 source 'https://rubygems.org'
 
 gemspec
+gem 'stackprof', platforms: :mri_21
+
+group :test do
+  gem 'spy', '0.4.1'
+  gem 'benchmark-ips'
+  gem 'rubocop'
+
+  platform :mri do
+    gem 'liquid-c', github: 'Shopify/liquid-c', ref: '35e9aee48d639ae1d3ac9ba77616aca9800eab7d'
+  end
+end

History.md

@@ -1,59 +1,122 @@
-# Liquid Version History
+# Liquid Change Log
 
-## 3.0.0 / not yet released / branch "master"
+## 4.0.0 / not yet released / branch "master"
 
-* ...
-* Add a to_s default for liquid drops, see #306 [Adam Doeler, releod]
-* Add strip, lstrip, and rstrip to standard filters [Florian Weingarten, fw42]
-* Make if, for & case tags return complete and consistent nodelists, see #250 [Nick Jones, dntj]
-* Prevent arbitrary method invocation on condition objects, see #274 [Dylan Thacker-Smith, dylanahsmith]
-* Don't call to_sym when creating conditions for security reasons, see #273 [Bouke van der Bijl, bouk]
-* Fix resource counting bug with respond_to?(:length), see #263 [Florian Weingarten, fw42]
-* Allow specifying custom patterns for template filenames, see #284 [Andrei Gladkyi, agladkyi]
-* Allow drops to optimize loading a slice of elements, see #282 [Tom Burns, boourns]
-* Support for passing variables to snippets in subdirs, see #271 [Joost Hietbrink, joost]
-* Add a class cache to avoid runtime extend calls, see #249 [James Tucker, raggi]
-* Remove some legacy Ruby 1.8 compatibility code, see #276 [Florian Weingarten, fw42]
-* Add default filter to standard filters, see #267 [Derrick Reimer, djreimer]
-* Add optional strict parsing and warn parsing, see #235 [Tristan Hume, trishume]
-* Add I18n syntax error translation, see #241 [Simon Hørup Eskildsen, Sirupsen]
-* Make sort filter work on enumerable drops, see #239 [Florian Weingarten, fw42]
-* Fix clashing method names in enumerable drops, see #238 [Florian Weingarten, fw42]
-* Make map filter work on enumerable drops, see #233 [Florian Weingarten, fw42]
-* Improved whitespace stripping for blank blocks, related to #216 [Florian Weingarten, fw42]
-* Raise `Liquid::ArgumentError` instead of `::ArgumentError` when filter has wrong number of arguments #309 [Bogdan Gusiev, bogdan]
+### Changed
+* Add compact filter (#600) [Carson Reinke]
+* Rename deprecated "has_key?" and "has_interrupt?" methods (#593) [Florian Weingarten]
+* Include template name with line numbers in render errors (574) [Dylan Thacker-Smith]
+* Add sort_natural filter (#554) [Martin Hanzel]
+* Add forloop.parentloop as a reference to the parent loop (#520) [Justin Li]
+* Block parsing moved to BlockBody class (#458) [Dylan Thacker-Smith]
+* Add concat filter to concatenate arrays (#429) [Diogo Beato]
+* Ruby 1.9 support dropped (#491) [Justin Li]
+* Liquid::Template.file_system's read_template_file method is no longer passed the context. (#441) [James Reid-Smith]
+* Remove support for `liquid_methods`
 
-## 2.6.0 / 2013-11-25 / branch "2.6-stable"
+### Fixed
+* Fix bug in uniq filter (#595) [Florian Weingarten]
+* Fix bug when "blank" and "empty" are used as variable names (#592) [Florian Weingarten]
+* Fix condition parse order in strict mode (#569) [Justin Li]
+* Fix naming of the "context variable" when dynamically including a template (#559) [Justin Li]
+* Gracefully accept empty strings in the date filter (#555) [Loren Hale]
+* Fix capturing into variables with a hyphen in the name (#505) [Florian Weingarten]
+* Fix case sensitivity regression in date standard filter (#499) [Kelley Reynolds]
+* Disallow filters with no variable in strict mode (#475) [Justin Li]
+* Disallow variable names in the strict parser that are not valid in the lax parser (#463) [Justin Li]
+* Fix BlockBody#warnings taking exponential time to compute (#486) [Justin Li]
+
+## 3.0.3 / 2015-05-28 / branch "3-0-stable"
+
+* Fix condition parse order in strict mode (#569) [Justin Li]
+
+## 3.0.2 / 2015-04-24
+
+* Expose VariableLookup private members (#551) [Justin Li]
+* Documentation fixes
+
+## 3.0.1 / 2015-01-23
+
+* Remove duplicate `index0` key in TableRow tag (#502) [Alfred Xing]
+
+## 3.0.0 / 2014-11-12
+
+* Removed Block#end_tag. Instead, override parse with `super` followed by your code. See #446 [Dylan Thacker-Smith]
+* Fixed condition with wrong data types (#423) [Bogdan Gusiev]
+* Add url_encode to standard filters (#421) [Derrick Reimer]
+* Add uniq to standard filters [Florian Weingarten]
+* Add exception_handler feature (#397) and #254 [Bogdan Gusiev, Florian Weingarten]
+* Optimize variable parsing to avoid repeated regex evaluation during template rendering #383 [Jason Hiltz-Laforge]
+* Optimize checking for block interrupts to reduce object allocation #380 [Jason Hiltz-Laforge]
+* Properly set context rethrow_errors on render! #349 [Thierry Joyal]
+* Fix broken rendering of variables which are equal to false (#345) [Florian Weingarten]
+* Remove ActionView template handler [Dylan Thacker-Smith]
+* Freeze lots of string literals for new Ruby 2.1 optimization (#297) [Florian Weingarten]
+* Allow newlines in tags and variables (#324) [Dylan Thacker-Smith]
+* Tag#parse is called after initialize, which now takes options instead of tokens as the 3rd argument. See #321 [Dylan Thacker-Smith]
+* Raise `Liquid::ArgumentError` instead of `::ArgumentError` when filter has wrong number of arguments #309 [Bogdan Gusiev]
+* Add a to_s default for liquid drops (#306) [Adam Doeler]
+* Add strip, lstrip, and rstrip to standard filters [Florian Weingarten]
+* Make if, for & case tags return complete and consistent nodelists (#250) [Nick Jones]
+* Prevent arbitrary method invocation on condition objects (#274) [Dylan Thacker-Smith]
+* Don't call to_sym when creating conditions for security reasons (#273) [Bouke van der Bijl]
+* Fix resource counting bug with respond_to?(:length) (#263) [Florian Weingarten]
+* Allow specifying custom patterns for template filenames (#284) [Andrei Gladkyi]
+* Allow drops to optimize loading a slice of elements (#282) [Tom Burns]
+* Support for passing variables to snippets in subdirs (#271) [Joost Hietbrink]
+* Add a class cache to avoid runtime extend calls (#249) [James Tucker]
+* Remove some legacy Ruby 1.8 compatibility code (#276) [Florian Weingarten]
+* Add default filter to standard filters (#267) [Derrick Reimer]
+* Add optional strict parsing and warn parsing (#235) [Tristan Hume]
+* Add I18n syntax error translation (#241) [Simon Hørup Eskildsen, Sirupsen]
+* Make sort filter work on enumerable drops (#239) [Florian Weingarten]
+* Fix clashing method names in enumerable drops (#238) [Florian Weingarten]
+* Make map filter work on enumerable drops (#233) [Florian Weingarten]
+* Improved whitespace stripping for blank blocks, related to #216 [Florian Weingarten]
+
+## 2.6.1 / 2014-01-10 / branch "2-6-stable"
+
+Security fix, cherry-picked from master (4e14a65):
+* Don't call to_sym when creating conditions for security reasons (#273) [Bouke van der Bijl]
+* Prevent arbitrary method invocation on condition objects (#274) [Dylan Thacker-Smith]
+
+## 2.6.0 / 2013-11-25
 
 IMPORTANT: Liquid 2.6 is going to be the last version of Liquid which maintains explicit Ruby 1.8 compatability.
 The following releases will only be tested against Ruby 1.9 and Ruby 2.0 and are likely to break on Ruby 1.8.
 
 * Bugfix for #106: fix example servlet [gnowoel]
-* Bugfix for #97: strip_html filter supports multi-line tags [Jo Liss, joliss]
-* Bugfix for #114: strip_html filter supports style tags [James Allardice, jamesallardice]
-* Bugfix for #117: 'now' support for date filter in Ruby 1.9 [Notre Dame Webgroup, ndwebgroup]
-* Bugfix for #166: truncate filter on UTF-8 strings with Ruby 1.8 [Florian Weingarten, fw42]
-* Bugfix for #204: 'raw' parsing bug [Florian Weingarten, fw42]
-* Bugfix for #150: 'for' parsing bug [Peter Schröder, phoet]
-* Bugfix for #126: Strip CRLF in strip_newline [Peter Schröder, phoet]
-* Bugfix for #174, "can't convert Fixnum into String" for "replace" [wǒ_is神仙, jsw0528]
-* Allow a Liquid::Drop to be passed into Template#render [Daniel Huckstep, darkhelmet]
-* Resource limits [Florian Weingarten, fw42]
-* Add reverse filter [Jay Strybis, unreal]
+* Bugfix for #97: strip_html filter supports multi-line tags [Jo Liss]
+* Bugfix for #114: strip_html filter supports style tags [James Allardice]
+* Bugfix for #117: 'now' support for date filter in Ruby 1.9 [Notre Dame Webgroup]
+* Bugfix for #166: truncate filter on UTF-8 strings with Ruby 1.8 [Florian Weingarten]
+* Bugfix for #204: 'raw' parsing bug [Florian Weingarten]
+* Bugfix for #150: 'for' parsing bug [Peter Schröder]
+* Bugfix for #126: Strip CRLF in strip_newline [Peter Schröder]
+* Bugfix for #174, "can't convert Fixnum into String" for "replace" [jsw0528]
+* Allow a Liquid::Drop to be passed into Template#render [Daniel Huckstep]
+* Resource limits [Florian Weingarten]
+* Add reverse filter [Jay Strybis]
 * Add utf-8 support
-* Use array instead of Hash to keep the registered filters [Tasos Stathopoulos, astathopoulos]
-* Cache tokenized partial templates [Tom Burns, boourns]
-* Avoid warnings in Ruby 1.9.3 [Marcus Stollsteimer, stomar]
-* Better documentation for 'include' tag (closes #163) [Peter Schröder, phoet]
-* Use of BigDecimal on filters to have better precision (closes #155) [Arthur Nogueira Neves, arthurnn]
+* Use array instead of Hash to keep the registered filters [Tasos Stathopoulos]
+* Cache tokenized partial templates [Tom Burns]
+* Avoid warnings in Ruby 1.9.3 [Marcus Stollsteimer]
+* Better documentation for 'include' tag (closes #163) [Peter Schröder]
+* Use of BigDecimal on filters to have better precision (closes #155) [Arthur Nogueira Neves]
 
-## 2.5.4 / 2013-11-11 / branch "2.5-stable"
+## 2.5.5 / 2014-01-10 / branch "2-5-stable"
 
-* Fix "can't convert Fixnum into String" for "replace", see #173, [wǒ_is神仙, jsw0528]
+Security fix, cherry-picked from master (4e14a65):
+* Don't call to_sym when creating conditions for security reasons (#273) [Bouke van der Bijl]
+* Prevent arbitrary method invocation on condition objects (#274) [Dylan Thacker-Smith]
+
+## 2.5.4 / 2013-11-11
+
+* Fix "can't convert Fixnum into String" for "replace" (#173), [jsw0528]
 
 ## 2.5.3 / 2013-10-09
 
-* #232, #234, #237: Fix map filter bugs [Florian Weingarten, fw42]
+* #232, #234, #237: Fix map filter bugs [Florian Weingarten]
 
 ## 2.5.2 / 2013-09-03 / deleted
 
@@ -61,7 +124,7 @@ Yanked from rubygems, as it contained too many changes that broke compatibility.
 
 ## 2.5.1 / 2013-07-24
 
-* #230: Fix security issue with map filter, Use invoke_drop in map filter [Florian Weingarten, fw42]
+* #230: Fix security issue with map filter, Use invoke_drop in map filter [Florian Weingarten]
 
 ## 2.5.0 / 2013-03-06
 

README.md

@@ -1,4 +1,6 @@
-[![Build Status](https://secure.travis-ci.org/Shopify/liquid.png?branch=master)](http://travis-ci.org/Shopify/liquid)
+[![Build Status](https://api.travis-ci.org/Shopify/liquid.svg?branch=master)](http://travis-ci.org/Shopify/liquid)
+[![Inline docs](http://inch-ci.org/github/Shopify/liquid.svg?branch=master)](http://inch-ci.org/github/Shopify/liquid)
+
 # Liquid template engine
 
 * [Contributing guidelines](CONTRIBUTING.md)

Rakefile

@@ -1,15 +1,14 @@
 require 'rake'
 require 'rake/testtask'
-require 'rake/extensiontask'
 $LOAD_PATH.unshift File.expand_path("../lib", __FILE__)
 require "liquid/version"
 
-task :default => 'test'
+task default: [:rubocop, :test]
 
 desc 'run test suite with default parser'
 Rake::TestTask.new(:base_test) do |t|
   t.libs << '.' << 'lib' << 'test'
-  t.test_files = FileList['test/liquid/**/*_test.rb']
+  t.test_files = FileList['test/{integration,unit}/**/*_test.rb']
   t.verbose = false
 end
 
@@ -19,25 +18,43 @@ task :warn_test do
   Rake::Task['base_test'].invoke
 end
 
+task :rubocop do
+  require 'rubocop/rake_task'
+  RuboCop::RakeTask.new
+end
+
 desc 'runs test suite with both strict and lax parsers'
 task :test do
   ENV['LIQUID_PARSER_MODE'] = 'lax'
   Rake::Task['base_test'].invoke
+
   ENV['LIQUID_PARSER_MODE'] = 'strict'
   Rake::Task['base_test'].reenable
   Rake::Task['base_test'].invoke
+
+  if RUBY_ENGINE == 'ruby'
+    ENV['LIQUID-C'] = '1'
+
+    ENV['LIQUID_PARSER_MODE'] = 'lax'
+    Rake::Task['base_test'].reenable
+    Rake::Task['base_test'].invoke
+
+    ENV['LIQUID_PARSER_MODE'] = 'strict'
+    Rake::Task['base_test'].reenable
+    Rake::Task['base_test'].invoke
+  end
 end
 
-task :gem => :build
+task gem: :build
 task :build do
   system "gem build liquid.gemspec"
 end
 
-task :install => :build do
+task install: :build do
   system "gem install liquid-#{Liquid::VERSION}.gem"
 end
 
-task :release => :build do
+task release: :build do
   system "git tag -a v#{Liquid::VERSION} -m 'Tagging #{Liquid::VERSION}'"
   system "git push --tags"
   system "gem push liquid-#{Liquid::VERSION}.gem"
@@ -45,7 +62,6 @@ task :release => :build do
 end
 
 namespace :benchmark do
-
   desc "Run the liquid benchmark with lax parsing"
   task :run do
     ruby "./performance/benchmark.rb lax"
@@ -57,23 +73,16 @@ namespace :benchmark do
   end
 end
 
-
 namespace :profile do
-
   desc "Run the liquid profile/performance coverage"
   task :run do
     ruby "./performance/profile.rb"
   end
 
-  task :stackprof do
-    ruby "./performance/stackprof.rb"
+  desc "Run the liquid profile/performance coverage with strict parsing"
+  task :strict do
+    ruby "./performance/profile.rb strict"
   end
-
-  desc "Run KCacheGrind"
-  task :grind => :run  do
-    system "qcachegrind /tmp/liquid.rubyprof_calltreeprinter.txt"
-  end
-
 end
 
 desc "Run example"
@@ -81,7 +90,6 @@ task :example do
   ruby "-w -d -Ilib example/server/server.rb"
 end
 
-Rake::ExtensionTask.new "liquid" do |ext|
-  ext.lib_dir = "lib/liquid"
+task :console do
+  exec 'irb -I lib -r liquid'
 end
-Rake::Task[:test].prerequisites << :compile

circle.yml

@@ -0,0 +1,3 @@
+machine:
+  ruby:
+    version: ruby-2.0

example/server/example_servlet.rb

@@ -4,7 +4,7 @@ module ProductsFilter
   end
 
   def prettyprint(text)
-    text.gsub( /\*(.*)\*/, '<b>\1</b>' )
+    text.gsub(/\*(.*)\*/, '<b>\1</b>')
   end
 
   def count(array)
@@ -17,25 +17,28 @@ module ProductsFilter
 end
 
 class Servlet < LiquidServlet
-
   def index
     { 'date' => Time.now }
   end
 
   def products
-    { 'products' => products_list, 'description' => description, 'section' => 'Snowboards', 'cool_products' => true}
+    { 'products' => products_list, 'more_products' => more_products_list, 'description' => description, 'section' => 'Snowboards', 'cool_products' => true }
   end
 
   private
 
   def products_list
-    [{'name' => 'Arbor Draft', 'price' => 39900, 'description' => 'the *arbor draft* is a excellent product' },
-    {'name' => 'Arbor Element', 'price' => 40000, 'description' => 'the *arbor element* rocks for freestyling'},
-    {'name' => 'Arbor Diamond', 'price' => 59900, 'description' => 'the *arbor diamond* is a made up product because im obsessed with arbor and have no creativity'}]
+    [{ 'name' => 'Arbor Draft', 'price' => 39900, 'description' => 'the *arbor draft* is a excellent product' },
+     { 'name' => 'Arbor Element', 'price' => 40000, 'description' => 'the *arbor element* rocks for freestyling' },
+     { 'name' => 'Arbor Diamond', 'price' => 59900, 'description' => 'the *arbor diamond* is a made up product because im obsessed with arbor and have no creativity' }]
+  end
+
+  def more_products_list
+    [{ 'name' => 'Arbor Catalyst', 'price' => 39900, 'description' => 'the *arbor catalyst* is an advanced drop-through for freestyle and flatground performance and versatility' },
+     { 'name' => 'Arbor Fish', 'price' => 40000, 'description' => 'the *arbor fish* is a compact pin that features an extended wheelbase and time-honored teardrop shape' }]
   end
 
   def description
     "List of Products ~ This is a list of products with price and description."
   end
-
 end

example/server/liquid_servlet.rb

@@ -1,5 +1,4 @@
 class LiquidServlet < WEBrick::HTTPServlet::AbstractServlet
-
   def do_GET(req, res)
     handle(:get, req, res)
   end
@@ -11,7 +10,8 @@ class LiquidServlet < WEBrick::HTTPServlet::AbstractServlet
   private
 
   def handle(type, req, res)
-    @request, @response = req, res
+    @request = req
+    @response = res
 
     @request.path_info =~ /(\w+)\z/
     @action = $1 || 'index'
@@ -19,10 +19,10 @@ class LiquidServlet < WEBrick::HTTPServlet::AbstractServlet
 
     @response['Content-Type'] = "text/html"
     @response.status = 200
-    @response.body = Liquid::Template.parse(read_template).render(@assigns, :filters => [ProductsFilter])
+    @response.body = Liquid::Template.parse(read_template).render(@assigns, filters: [ProductsFilter])
   end
 
   def read_template(filename = @action)
-    File.read( File.dirname(__FILE__) + "/templates/#{filename}.liquid" )
+    File.read("#{__dir__}/templates/#{filename}.liquid")
   end
 end

example/server/server.rb

@@ -1,14 +1,12 @@
 require 'webrick'
 require 'rexml/document'
 
-DIR = File.expand_path(File.dirname(__FILE__))
-
-require DIR + '/../../lib/liquid'
-require DIR + '/liquid_servlet'
-require DIR + '/example_servlet'
+require_relative '../../lib/liquid'
+require_relative 'liquid_servlet'
+require_relative 'example_servlet'
 
 # Setup webrick
-server = WEBrick::HTTPServer.new( :Port => ARGV[1] || 3000 )
+server = WEBrick::HTTPServer.new(Port: ARGV[1] || 3000)
 server.mount('/', Servlet)
 trap("INT"){ server.shutdown }
 server.start

example/server/templates/index.liquid

@@ -3,4 +3,4 @@
 <p>It is {{date}}</p>
 
 
-<p>Check out the <a href="http://localhost:3000/products">Products</a> screen </p>
+<p>Check out the <a href="/products">Products</a> screen </p>

example/server/templates/products.liquid

@@ -16,12 +16,12 @@
   </head>
 
   <body>
-
+    {% assign all_products = products | concat: more_products  %}
     <h1>{{ description | split: '~' | first }}</h1>
 
     <h2>{{ description | split: '~' | last }}</h2>
 
-    <h2>There are currently {{products | count}} products in the {{section}} catalog</h2>
+    <h2>There are currently {{all_products | count}} products in the {{section}} catalog</h2>
 
     {% if cool_products %}
       Cool products :)
@@ -31,7 +31,7 @@
 
     <ul id="products">
 
-      {% for product in products %}
+      {% for product in all_products %}
         <li>
           <h2>{{product.name}}</h2>
           Only {{product.price | price }}

ext/liquid/block.c

@@ -1,168 +0,0 @@
-#include "liquid_ext.h"
-
-VALUE cLiquidBlock;
-ID intern_assert_missing_delimitation, intern_block_delimiter, intern_is_blank, intern_new,
-   intern_new_with_options, intern_tags, intern_unknown_tag, intern_unterminated_tag,
-   intern_unterminated_variable;
-
-struct liquid_tag
-{
-    char *name, *markup;
-    long name_length, markup_length;
-};
-
-static bool parse_tag(struct liquid_tag *tag, char *token, long token_length)
-{
-    // Strip {{ and }} braces
-    token += 2;
-    token_length -= 4;
-
-    char *end = token + token_length;
-    while (token < end && isspace(*token))
-        token++;
-    tag->name = token;
-
-    char c = *token;
-    while (token < end && (isalnum(c) || c == '_'))
-        c = *(++token);
-    tag->name_length = token - tag->name;
-    if (!tag->name_length) {
-        memset(tag, 0, sizeof(*tag));
-        return false;
-    }
-
-    while (token < end && isspace(*token))
-        token++;
-    tag->markup = token;
-
-    char *last = end - 1;
-    while (token < last && isspace(*last))
-        last--;
-    end = last + 1;
-    tag->markup_length = end - token;
-    return true;
-}
-
-static VALUE rb_parse_body(VALUE self, VALUE tokenizerObj)
-{
-    struct liquid_tokenizer *tokenizer = LIQUID_TOKENIZER_GET_STRUCT(tokenizerObj);
-
-    bool blank = true;
-    VALUE nodelist = rb_iv_get(self, "@nodelist");
-    if (nodelist == Qnil) {
-        nodelist = rb_ary_new();
-        rb_iv_set(self, "@nodelist", nodelist);
-    } else {
-        rb_ary_clear(nodelist);
-    }
-
-    struct token token;
-    while (true) {
-        liquid_tokenizer_next(tokenizer, &token);
-        switch (token.type) {
-        case TOKEN_NONE:
-            /*
-             * Make sure that it's ok to end parsing in the current block.
-             * Effectively this method will throw an exception unless the current block is
-             * of type Document
-             */
-            rb_funcall(self, intern_assert_missing_delimitation, 0);
-            goto done;
-        case TOKEN_INVALID:
-        {
-            VALUE token_obj = rb_str_new(token.str, token.length);
-            if (token.str[1] == '%')
-                rb_funcall(self, intern_unterminated_tag, 1, token_obj);
-            else
-                rb_funcall(self, intern_unterminated_variable, 1, token_obj);
-            break;
-        }
-        case TOKEN_TAG:
-        {
-            struct liquid_tag tag;
-            if (!parse_tag(&tag, token.str, token.length)) {
-                // FIXME: provide more appropriate error message
-                rb_funcall(self, intern_unterminated_tag, 1, rb_str_new(token.str, token.length));
-            } else {
-                if (tag.name_length >= 3 && !memcmp(tag.name, "end", 3)) {
-                    VALUE block_delimiter = rb_funcall(self, intern_block_delimiter, 0);
-                    if (TYPE(block_delimiter) == T_STRING &&
-                        tag.name_length == RSTRING_LEN(block_delimiter) &&
-                        !memcmp(tag.name, RSTRING_PTR(block_delimiter), tag.name_length))
-                    {
-                        goto done;
-                    }
-                }
-
-                VALUE tags = rb_funcall(cLiquidTemplate, intern_tags, 0);
-                Check_Type(tags, T_HASH);
-                VALUE tag_name = rb_str_new(tag.name, tag.name_length);
-                VALUE tag_class = rb_hash_lookup(tags, tag_name);
-                VALUE markup = rb_str_new(tag.markup, tag.markup_length);
-                if (tag_class != Qnil) {
-                    VALUE options = rb_iv_get(self, "@options");
-                    if (options == Qnil)
-                        options = rb_hash_new();
-                    VALUE new_tag = rb_funcall(tag_class, intern_new_with_options, 4,
-                                               tag_name, markup, tokenizerObj, options);
-                    if (blank) {
-                        VALUE blank_block = rb_funcall(new_tag, intern_is_blank, 0);
-                        if (blank_block == Qnil || blank_block == Qfalse)
-                            blank = false;
-                    }
-                    rb_ary_push(nodelist, new_tag);
-                } else {
-                    rb_funcall(self, intern_unknown_tag, 3, tag_name, markup, tokenizerObj);
-                    /*
-                     * multi-block tags may store the nodelist in a block array on unknown_tag
-                     * then replace @nodelist with a new array. We need to use the new array
-                     * for the block following the tag token.
-                     */
-                    nodelist = rb_iv_get(self, "@nodelist");
-                }
-            }
-            break;
-        }
-        case TOKEN_VARIABLE:
-        {
-            VALUE markup = rb_str_new(token.str + 2, token.length - 4);
-            VALUE options = rb_iv_get(self, "@options");
-            VALUE new_var = rb_funcall(cLiquidVariable, intern_new, 2, markup, options);
-            rb_ary_push(nodelist, new_var);
-            blank = false;
-            break;
-        }
-        case TOKEN_STRING:
-            rb_ary_push(nodelist, rb_str_new(token.str, token.length));
-            if (blank) {
-                int i;
-                for (i = 0; i < token.length; i++) {
-                    if (!isspace(token.str[i])) {
-                        blank = false;
-                        break;
-                    }
-                }
-            }
-            break;
-        }
-    }
-done:
-    rb_iv_set(self, "@blank", blank ? Qtrue : Qfalse);
-    return Qnil;
-}
-
-void init_liquid_block()
-{
-    intern_assert_missing_delimitation = rb_intern("assert_missing_delimitation!");
-    intern_block_delimiter = rb_intern("block_delimiter");
-    intern_is_blank = rb_intern("blank?");
-    intern_new = rb_intern("new");
-    intern_new_with_options = rb_intern("new_with_options");
-    intern_tags = rb_intern("tags");
-    intern_unknown_tag = rb_intern("unknown_tag");
-    intern_unterminated_tag = rb_intern("unterminated_tag");
-    intern_unterminated_variable = rb_intern("unterminated_variable");
-
-    cLiquidBlock = rb_define_class_under(mLiquid, "Block", cLiquidTag);
-    rb_define_method(cLiquidBlock, "parse_body", rb_parse_body, 1);
-}

ext/liquid/block.h

@@ -1,8 +0,0 @@
-#ifndef LIQUID_BLOCK_H
-#define LIQUID_BLOCK_H
-
-void init_liquid_block();
-
-extern VALUE cLiquidBlock;
-
-#endif

ext/liquid/extconf.rb

@@ -1,3 +0,0 @@
-require 'mkmf'
-$CFLAGS << ' -Wall'
-create_makefile("liquid/liquid")

ext/liquid/liquid_ext.c

@@ -1,16 +0,0 @@
-#include "liquid_ext.h"
-
-VALUE mLiquid;
-VALUE cLiquidTemplate, cLiquidTag, cLiquidVariable;
-
-void Init_liquid(void)
-{
-    mLiquid = rb_define_module("Liquid");
-    cLiquidTemplate = rb_define_class_under(mLiquid, "Template", rb_cObject);
-    cLiquidTag = rb_define_class_under(mLiquid, "Tag", rb_cObject);
-    cLiquidVariable = rb_define_class_under(mLiquid, "Variable", rb_cObject);
-
-    init_liquid_tokenizer();
-    init_liquid_block();
-    init_liquid_variable();
-}

ext/liquid/liquid_ext.h

@@ -1,16 +0,0 @@
-#ifndef LIQUID_EXT_H
-#define LIQUID_EXT_H
-
-#include <stdbool.h>
-#include <ctype.h>
-#include <ruby.h>
-
-#include "tokenizer.h"
-#include "block.h"
-#include "utils.h"
-#include "variable.h"
-
-extern VALUE mLiquid;
-extern VALUE cLiquidTemplate, cLiquidTag, cLiquidVariable;
-
-#endif

ext/liquid/tokenizer.c

@@ -1,113 +0,0 @@
-#include "liquid_ext.h"
-
-VALUE cLiquidTokenizer;
-
-static void free_tokenizer(void *ptr)
-{
-    struct liquid_tokenizer *tokenizer = ptr;
-    xfree(tokenizer);
-}
-
-static VALUE rb_allocate(VALUE klass)
-{
-    VALUE obj;
-    struct liquid_tokenizer *tokenizer;
-
-    obj = Data_Make_Struct(klass, struct liquid_tokenizer, NULL, free_tokenizer, tokenizer);
-    return obj;
-}
-
-static VALUE rb_initialize(VALUE self, VALUE source)
-{
-    struct liquid_tokenizer *tokenizer;
-
-    Check_Type(source, T_STRING);
-    Data_Get_Struct(self, struct liquid_tokenizer, tokenizer);
-    tokenizer->cursor = RSTRING_PTR(source);
-    tokenizer->length = RSTRING_LEN(source);
-    return Qnil;
-}
-
-void liquid_tokenizer_next(struct liquid_tokenizer *tokenizer, struct token *token)
-{
-    if (tokenizer->length <= 0) {
-        memset(token, 0, sizeof(*token));
-        return;
-    }
-    token->type = TOKEN_STRING;
-
-    char *cursor = tokenizer->cursor;
-    char *last = tokenizer->cursor + tokenizer->length - 1;
-
-    while (cursor < last) {
-        if (*cursor++ != '{')
-            continue;
-
-        char c = *cursor++;
-        if (c != '%' && c != '{')
-            continue;
-        if (cursor - tokenizer->cursor > 2) {
-            token->type = TOKEN_STRING;
-            cursor -= 2;
-            goto found;
-        }
-        char *incomplete_end = cursor;
-        token->type = TOKEN_INVALID;
-        if (c == '%') {
-            while (cursor < last) {
-                if (*cursor++ != '%')
-                    continue;
-                c = *cursor++;
-                while (c == '%' && cursor <= last)
-                    c = *cursor++;
-                if (c != '}')
-                    continue;
-                token->type = TOKEN_TAG;
-                goto found;
-            }
-            cursor = incomplete_end;
-            goto found;
-        } else {
-            while (cursor < last) {
-                if (*cursor++ != '}')
-                    continue;
-                if (*cursor++ != '}') {
-                    incomplete_end = cursor - 1;
-                    continue;
-                }
-                token->type = TOKEN_VARIABLE;
-                goto found;
-            }
-            cursor = incomplete_end;
-            goto found;
-        }
-    }
-    cursor = last + 1;
-found:
-    token->str = tokenizer->cursor;
-    token->length = cursor - tokenizer->cursor;
-    tokenizer->cursor += token->length;
-    tokenizer->length -= token->length;
-}
-
-static VALUE rb_next(VALUE self)
-{
-    struct liquid_tokenizer *tokenizer;
-    Data_Get_Struct(self, struct liquid_tokenizer, tokenizer);
-
-    struct token token;
-    liquid_tokenizer_next(tokenizer, &token);
-    if (token.type == TOKEN_NONE)
-        return Qnil;
-
-    return rb_str_new(token.str, token.length);
-}
-
-void init_liquid_tokenizer()
-{
-    cLiquidTokenizer = rb_define_class_under(mLiquid, "Tokenizer", rb_cObject);
-    rb_define_alloc_func(cLiquidTokenizer, rb_allocate);
-    rb_define_method(cLiquidTokenizer, "initialize", rb_initialize, 1);
-    rb_define_method(cLiquidTokenizer, "next", rb_next, 0);
-    rb_define_alias(cLiquidTokenizer, "shift", "next");
-}

ext/liquid/tokenizer.h

@@ -1,30 +0,0 @@
-#ifndef LIQUID_TOKENIZER_H
-#define LIQUID_TOKENIZER_H
-
-extern VALUE cLiquidTokenizer;
-
-enum token_type {
-    TOKEN_NONE,
-    TOKEN_INVALID,
-    TOKEN_STRING,
-    TOKEN_TAG,
-    TOKEN_VARIABLE
-};
-
-struct token {
-    enum token_type type;
-    char *str;
-    int length;
-};
-
-struct liquid_tokenizer {
-    char *cursor;
-    int length;
-};
-
-void init_liquid_tokenizer();
-void liquid_tokenizer_next(struct liquid_tokenizer *tokenizer, struct token *token);
-
-#define LIQUID_TOKENIZER_GET_STRUCT(obj) ((struct liquid_tokenizer *)obj_get_data_ptr(obj, cLiquidTokenizer))
-
-#endif

ext/liquid/utils.c

@@ -1,21 +0,0 @@
-#include <ruby.h>
-
-void raise_type_error(VALUE expected, VALUE got)
-{
-    rb_raise(rb_eTypeError, "wrong argument type %s (expected %s)",
-                             rb_class2name(got), rb_class2name(expected));
-}
-
-void check_class(VALUE obj, int type, VALUE klass)
-{
-    Check_Type(obj, type);
-    VALUE obj_klass = RBASIC_CLASS(obj);
-    if (obj_klass != klass)
-        raise_type_error(klass, obj_klass);
-}
-
-void *obj_get_data_ptr(VALUE obj, VALUE klass)
-{
-    check_class(obj, T_DATA, klass);
-    return DATA_PTR(obj);
-}

ext/liquid/utils.h

@@ -1,8 +0,0 @@
-#ifndef LIQUID_UTILS_H
-#define LIQUID_UTILS_H
-
-void raise_type_error(VALUE expected, VALUE got);
-void check_class(VALUE klass);
-void *obj_get_data_ptr(VALUE obj, VALUE klass);
-
-#endif

ext/liquid/variable.c

@@ -1,179 +0,0 @@
-#include "liquid_ext.h"
-
-VALUE cLiquidVariable;
-extern VALUE mLiquid;
-
-static void free_variable(void *ptr)
-{
-    struct liquid_variable *variable = ptr;
-    xfree(variable);
-}
-
-static VALUE rb_variable_allocate(VALUE klass)
-{
-    VALUE obj;
-    struct liquid_variable *variable;
-
-    obj = Data_Make_Struct(klass, struct liquid_variable, NULL, free_variable, variable);
-    return obj;
-}
-
-static inline int skip_whitespace(char * str, int len) 
-{
-  int skipped = 0; char * ptr = str;
-  while (skipped < len && isspace(*ptr))
-    {skipped++; ptr++;}
-  return skipped;
-}
-
-static char * get_quoted_fragment(char * str, int len, int * ret_size, int * end_offset, bool colon) 
-{
-  int p = 0; /* Current position in string */
-  int start = -1, end = -1; /* Start and end indices for the found string */
-  char quoted_by = -1; /* Is the current part of string quoted by a single or double quote? If so 
-                          ignore any special chars */
-
-  while (p < len) {
-    
-    switch (str[p]) {
-      case '"': 
-        if (start == -1) {start = p; quoted_by = '"';}
-        else if (str[start] == '"') {end = p; goto quoted_fragment_found;}
-        else if (quoted_by == -1) quoted_by = '"';
-        else if (quoted_by == '"') quoted_by = -1;
-        break;
-      case '\'':
-        if (start == -1) {start = p; quoted_by = '\'';}
-        else if (str[start] == '\'') {end = p; goto quoted_fragment_found;}
-        else if (quoted_by == -1) quoted_by = '\'';
-        else if (quoted_by == '\'') quoted_by = -1;
-        break;
-      case ':': 
-        if (colon)
-          if (start != -1 && quoted_by == -1) {end = p-1; goto quoted_fragment_found;} 
-        else
-          if (start == -1) start = p;
-        break;
-      case '|':
-      case ',':
-      case '\n':
-      case '\r':
-      case '\f':
-      case '\t':
-      case '\v':
-      case ' ': 
-        if (start != -1 && quoted_by == -1) {end = p-1; goto quoted_fragment_found;} 
-        break;
-      default: 
-        if (start == -1) start = p; 
-        break;
-    }
-    p++;
-  }
-  if (p == len && start != -1 && end == -1) end = len-1;
-
-quoted_fragment_found:
-  if (end >= start) {
-    *ret_size = end-start+1;
-    *end_offset = end+1;
-    return &str[start];
-  } else {
-    *ret_size = 0;
-    return NULL;
-  }
-}
-
-static VALUE get_filters(char * str, int len, VALUE self) {
-  VALUE filters_arr = rb_ary_new(); 
-
-  int p = 0; 
-  int ret_size, end_offset; 
-  char * f;
-
-  while(p<len) {
-    if (str[p] == '|') {
-      VALUE filter = rb_ary_new();
-      VALUE f_args = rb_ary_new();
-
-      p += skip_whitespace(&str[p+1], len-p-1);
-      f = get_quoted_fragment(&str[p], len-p, &ret_size, &end_offset, true);
-      p += end_offset;
-
-      if (f) {
-        if (f[ret_size-1] == ':') ret_size--;
-        rb_ary_push(filter, rb_str_new(f, ret_size));
-      }
-
-      /* Check for filter arguments */
-      do {
-        if (p<len) {
-          p += skip_whitespace(&str[p], len-p);
-
-          // printf("\n1. %.*s\n", len-p, &str[p]);
-
-          if (str[p] != '|') {
-            f = get_quoted_fragment(&str[p], len-p, &ret_size, &end_offset, false);
-
-            // printf("\n2. %.*s\n", ret_size, f);
-            
-            p += end_offset;
-            p += skip_whitespace(&str[p], len-p);
-
-            if (str[p] == '|') p--;
-
-            if (f) rb_ary_push(f_args, rb_str_new(f, ret_size));
-          
-          } else p--;
-        }
-
-      } while (str[p] == ',' || str[p] == ':');
-
-      rb_ary_push(filter, f_args);
-
-      /* Add to filters_arr array */
-      rb_ary_push(filters_arr, filter);
-    }
-    p++;
-  }
-  return filters_arr;
-}
-
-static VALUE rb_variable_lax_parse(VALUE self, VALUE m) 
-{
-  char * markup = RSTRING_PTR(m);
-  int markup_len = RSTRING_LEN(m);
-
-  char * cursor = markup; int cursor_pos = 0; 
-  VALUE filters_arr; 
-  int size, end_offset;
-
-  /* Extract name */
-  cursor_pos += skip_whitespace(markup, markup_len); 
-  cursor = markup + cursor_pos;
-  cursor = get_quoted_fragment(cursor, markup_len - cursor_pos, &size, &end_offset, false);
-
-  if (cursor == NULL) {
-    rb_iv_set(self, "@name", Qnil);
-    filters_arr = rb_ary_new(); 
-    rb_iv_set(self, "@filters", filters_arr);
-  }
-  else 
-  {
-    rb_iv_set(self, "@name", rb_str_new(cursor, size));
-
-    /* Extract filters */
-    if (end_offset < markup_len) {
-      cursor = &markup[end_offset];
-      filters_arr = get_filters(cursor, markup_len - end_offset, self);
-      rb_iv_set(self, "@filters", filters_arr);
-    }
-  }
-  return filters_arr;
-}
-
-void init_liquid_variable()
-{
-    cLiquidVariable = rb_define_class_under(mLiquid, "Variable", rb_cObject);
-    rb_define_alloc_func(cLiquidVariable, rb_variable_allocate);
-    rb_define_method(cLiquidVariable, "lax_parse", rb_variable_lax_parse, 1);
-}

ext/liquid/variable.h

@@ -1,13 +0,0 @@
-#ifndef LIQUID_VARIABLE_H
-#define LIQUID_VARIABLE_H
-
-#include <regex.h>
-
-struct liquid_variable {
-    char *markup; long markup_len;
-    char *name; long name_len;
-};
-
-void init_liquid_variable();
-
-#endif

init.rb

@@ -1,8 +0,0 @@
-require 'liquid'
-require 'extras/liquid_view'
-
-if defined? ActionView::Template and ActionView::Template.respond_to? :register_template_handler
-  ActionView::Template
-else
-  ActionView::Base
-end.register_template_handler(:liquid, LiquidView)

lib/extras/liquid_view.rb

@@ -1,51 +0,0 @@
-# LiquidView is a action view extension class. You can register it with rails
-# and use liquid as an template system for .liquid files
-#
-# Example
-#
-#   ActionView::Base::register_template_handler :liquid, LiquidView
-class LiquidView
-  PROTECTED_ASSIGNS = %w( template_root response _session template_class action_name request_origin session template
-                          _response url _request _cookies variables_added _flash params _headers request cookies
-                          ignore_missing_templates flash _params logger before_filter_chain_aborted headers )
-  PROTECTED_INSTANCE_VARIABLES = %w( @_request @controller @_first_render @_memoized__pick_template @view_paths
-                                     @helpers @assigns_added @template @_render_stack @template_format @assigns )
-
-  def self.call(template)
-    "LiquidView.new(self).render(template, local_assigns)"
-  end
-
-  def initialize(view)
-    @view = view
-  end
-
-  def render(template, local_assigns = nil)
-    @view.controller.headers["Content-Type"] ||= 'text/html; charset=utf-8'
-
-    # Rails 2.2 Template has source, but not locals
-    if template.respond_to?(:source) && !template.respond_to?(:locals)
-      assigns = (@view.instance_variables - PROTECTED_INSTANCE_VARIABLES).inject({}) do |hash, ivar|
-                  hash[ivar[1..-1]] = @view.instance_variable_get(ivar)
-                  hash
-                end
-    else
-      assigns = @view.assigns.reject{ |k,v| PROTECTED_ASSIGNS.include?(k) }
-    end
-
-    source = template.respond_to?(:source) ? template.source : template
-    local_assigns = (template.respond_to?(:locals) ? template.locals : local_assigns) || {}
-
-    if content_for_layout = @view.instance_variable_get("@content_for_layout")
-      assigns['content_for_layout'] = content_for_layout
-    end
-    assigns.merge!(local_assigns.stringify_keys)
-
-    liquid = Liquid::Template.parse(source)
-    liquid.render(assigns, :filters => [@view.controller.master_helper_module], :registers => {:action_view => @view, :controller => @view.controller})
-  end
-
-  def compilable?
-    false
-  end
-
-end

lib/liquid.rb

@@ -21,27 +21,28 @@
 
 module Liquid
   FilterSeparator             = /\|/
-  ArgumentSeparator           = ','
-  FilterArgumentSeparator     = ':'
-  VariableAttributeSeparator  = '.'
+  ArgumentSeparator           = ','.freeze
+  FilterArgumentSeparator     = ':'.freeze
+  VariableAttributeSeparator  = '.'.freeze
   TagStart                    = /\{\%/
   TagEnd                      = /\%\}/
   VariableSignature           = /\(?[\w\-\.\[\]]\)?/
   VariableSegment             = /[\w\-]/
   VariableStart               = /\{\{/
   VariableEnd                 = /\}\}/
+  VariableIncompleteEnd       = /\}\}?/
   QuotedString                = /"[^"]*"|'[^']*'/
   QuotedFragment              = /#{QuotedString}|(?:[^\s,\|'"]|#{QuotedString})+/o
-  StrictQuotedFragment        = /"[^"]+"|'[^']+'|[^\s|:,]+/
-  FirstFilterArgument         = /#{FilterArgumentSeparator}(?:#{StrictQuotedFragment})/o
-  OtherFilterArgument         = /#{ArgumentSeparator}(?:#{StrictQuotedFragment})/o
-  SpacelessFilter             = /\A(?:'[^']+'|"[^"]+"|[^'"])*#{FilterSeparator}(?:#{StrictQuotedFragment})(?:#{FirstFilterArgument}(?:#{OtherFilterArgument})*)?/o
-  Expression                  = /(?:#{QuotedFragment}(?:#{SpacelessFilter})*)/o
   TagAttributes               = /(\w+)\s*\:\s*(#{QuotedFragment})/o
+  AnyStartingTag              = /\{\{|\{\%/
+  PartialTemplateParser       = /#{TagStart}.*?#{TagEnd}|#{VariableStart}.*?#{VariableIncompleteEnd}/om
+  TemplateParser              = /(#{PartialTemplateParser}|#{AnyStartingTag})/om
   VariableParser              = /\[[^\]]+\]|#{VariableSegment}+\??/o
+
+  singleton_class.send(:attr_accessor, :cache_classes)
+  self.cache_classes = true
 end
 
-require 'liquid/liquid'
 require "liquid/version"
 require 'liquid/lexer'
 require 'liquid/parser'
@@ -51,19 +52,25 @@ require 'liquid/extensions'
 require 'liquid/errors'
 require 'liquid/interrupts'
 require 'liquid/strainer'
+require 'liquid/expression'
 require 'liquid/context'
+require 'liquid/parser_switching'
 require 'liquid/tag'
 require 'liquid/block'
+require 'liquid/block_body'
 require 'liquid/document'
 require 'liquid/variable'
+require 'liquid/variable_lookup'
+require 'liquid/range_lookup'
 require 'liquid/file_system'
+require 'liquid/resource_limits'
 require 'liquid/template'
-require 'liquid/htmltags'
 require 'liquid/standardfilters'
 require 'liquid/condition'
-require 'liquid/module_ex'
 require 'liquid/utils'
+require 'liquid/tokenizer'
+require 'liquid/token'
 
 # Load all the tags of the standard library
 #
-Dir[File.dirname(__FILE__) + '/liquid/tags/*.rb'].each { |f| require f }
+Dir["#{__dir__}/liquid/tags/*.rb"].each { |f| require f }

lib/liquid/block.rb

@@ -1,12 +1,26 @@
 module Liquid
   class Block < Tag
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
       super
-      parse_body(tokens)
+      @blank = true
+    end
+
+    def parse(tokens)
+      @body = BlockBody.new
+      while parse_body(@body, tokens)
+      end
+    end
+
+    def render(context)
+      @body.render(context)
     end
 
     def blank?
-      @blank || false
+      @blank
+    end
+
+    def nodelist
+      @body.nodelist
     end
 
     # warnings of this block and all sub-tags
@@ -21,81 +35,45 @@ module Liquid
       all_warnings
     end
 
-    def unknown_tag(tag, params, tokens)
+    def unknown_tag(tag, _params, _tokens)
       case tag
-      when 'else'
-        raise SyntaxError.new(options[:locale].t("errors.syntax.unexpected_else", 
-                                                 :block_name => block_name))
-      when 'end'
-        raise SyntaxError.new(options[:locale].t("errors.syntax.invalid_delimiter", 
-                                                 :block_name => block_name, 
-                                                 :block_delimiter => block_delimiter))
+      when 'else'.freeze
+        raise SyntaxError.new(options[:locale].t("errors.syntax.unexpected_else".freeze,
+          block_name: block_name))
+      when 'end'.freeze
+        raise SyntaxError.new(options[:locale].t("errors.syntax.invalid_delimiter".freeze,
+          block_name: block_name,
+          block_delimiter: block_delimiter))
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.unknown_tag", :tag => tag))
+        raise SyntaxError.new(options[:locale].t("errors.syntax.unknown_tag".freeze, tag: tag))
       end
     end
 
-    def block_delimiter
-      "end#{block_name}"
-    end
-
     def block_name
       @tag_name
     end
 
-    def render(context)
-      render_all(@nodelist, context)
+    def block_delimiter
+      @block_delimiter ||= "end#{block_name}"
     end
 
     protected
 
-    def unterminated_variable(token)
-      raise SyntaxError.new(options[:locale].t("errors.syntax.variable_termination", :token => token, :tag_end => VariableEnd.inspect))
-    end
+    def parse_body(body, tokens)
+      body.parse(tokens, options) do |end_tag_name, end_tag_params|
+        @blank &&= body.blank?
 
-    def unterminated_tag(token)
-      raise SyntaxError.new(options[:locale].t("errors.syntax.tag_termination", :token => token, :tag_end => TagEnd.inspect))
-    end
-
-    def assert_missing_delimitation!
-      raise SyntaxError.new(options[:locale].t("errors.syntax.tag_never_closed", :block_name => block_name))
-    end
-
-    def render_all(list, context)
-      output = []
-      context.resource_limits[:render_length_current] = 0
-      context.resource_limits[:render_score_current] += list.length
-
-      list.each do |token|
-        # Break out if we have any unhanded interrupts.
-        break if context.has_interrupt?
-
-        begin
-          # If we get an Interrupt that means the block must stop processing. An
-          # Interrupt is any command that stops block execution such as {% break %}
-          # or {% continue %}
-          if token.is_a? Continue or token.is_a? Break
-            context.push_interrupt(token.interrupt)
-            break
-          end
-
-          token_output = (token.respond_to?(:render) ? token.render(context) : token)
-          context.increment_used_resources(:render_length_current, token_output)
-          if context.resource_limits_reached?
-            context.resource_limits[:reached] = true
-            raise MemoryError.new("Memory limits exceeded")
-          end
-          unless token.is_a?(Block) && token.blank?
-            output << token_output
-          end
-        rescue MemoryError => e
-          raise e
-        rescue ::StandardError => e
-          output << (context.handle_error(e))
+        return false if end_tag_name == block_delimiter
+        unless end_tag_name
+          raise SyntaxError.new(@options[:locale].t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
         end
+
+        # this tag is not registered with the system
+        # pass it to the current block for special handling or error reporting
+        unknown_tag(end_tag_name, end_tag_params, tokens)
       end
 
-      output.join
+      true
     end
   end
 end

lib/liquid/block_body.rb

@@ -0,0 +1,135 @@
+module Liquid
+  class BlockBody
+    FullToken = /\A#{TagStart}\s*(\w+)\s*(.*)?#{TagEnd}\z/om
+    ContentOfVariable = /\A#{VariableStart}(.*)#{VariableEnd}\z/om
+    TAGSTART = "{%".freeze
+    VARSTART = "{{".freeze
+
+    attr_reader :nodelist
+
+    def initialize
+      @nodelist = []
+      @blank = true
+    end
+
+    def parse(tokens, options)
+      while token = tokens.shift
+        begin
+          unless token.empty?
+            case
+            when token.start_with?(TAGSTART)
+              if token =~ FullToken
+                tag_name = $1
+                markup = $2
+                # fetch the tag from registered blocks
+                if tag = registered_tags[tag_name]
+                  markup = token.child(markup) if token.is_a?(Token)
+                  new_tag = tag.parse(tag_name, markup, tokens, options)
+                  new_tag.line_number = token.line_number if token.is_a?(Token)
+                  @blank &&= new_tag.blank?
+                  @nodelist << new_tag
+                else
+                  # end parsing if we reach an unknown tag and let the caller decide
+                  # determine how to proceed
+                  return yield tag_name, markup
+                end
+              else
+                raise_missing_tag_terminator(token, options)
+              end
+            when token.start_with?(VARSTART)
+              new_var = create_variable(token, options)
+              new_var.line_number = token.line_number if token.is_a?(Token)
+              @nodelist << new_var
+              @blank = false
+            else
+              @nodelist << token
+              @blank &&= !!(token =~ /\A\s*\z/)
+            end
+          end
+        rescue SyntaxError => e
+          e.set_line_number_from_token(token)
+          raise
+        end
+      end
+
+      yield nil, nil
+    end
+
+    def blank?
+      @blank
+    end
+
+    def warnings
+      all_warnings = []
+      nodelist.each do |node|
+        all_warnings.concat(node.warnings || []) if node.respond_to?(:warnings)
+      end
+      all_warnings
+    end
+
+    def render(context)
+      output = []
+      context.resource_limits.render_score += @nodelist.length
+
+      @nodelist.each do |token|
+        # Break out if we have any unhanded interrupts.
+        break if context.interrupt?
+
+        begin
+          # If we get an Interrupt that means the block must stop processing. An
+          # Interrupt is any command that stops block execution such as {% break %}
+          # or {% continue %}
+          if token.is_a?(Continue) || token.is_a?(Break)
+            context.push_interrupt(token.interrupt)
+            break
+          end
+
+          token_output = render_token(token, context)
+
+          unless token.is_a?(Block) && token.blank?
+            output << token_output
+          end
+        rescue MemoryError => e
+          raise e
+        rescue ::StandardError => e
+          output << context.handle_error(e, token)
+        end
+      end
+
+      output.join
+    end
+
+    private
+
+    def render_token(token, context)
+      token_output = (token.respond_to?(:render) ? token.render(context) : token)
+      token_str = token_output.is_a?(Array) ? token_output.join : token_output.to_s
+
+      context.resource_limits.render_length += token_str.length
+      if context.resource_limits.reached?
+        raise MemoryError.new("Memory limits exceeded".freeze)
+      end
+      token_str
+    end
+
+    def create_variable(token, options)
+      token.scan(ContentOfVariable) do |content|
+        markup = token.is_a?(Token) ? token.child(content.first) : content.first
+        return Variable.new(markup, options)
+      end
+      raise_missing_variable_terminator(token, options)
+    end
+
+    def raise_missing_tag_terminator(token, options)
+      raise SyntaxError.new(options[:locale].t("errors.syntax.tag_termination".freeze, token: token, tag_end: TagEnd.inspect))
+    end
+
+    def raise_missing_variable_terminator(token, options)
+      raise SyntaxError.new(options[:locale].t("errors.syntax.variable_termination".freeze, token: token, tag_end: VariableEnd.inspect))
+    end
+
+    def registered_tags
+      Template.tags
+    end
+  end
+end

lib/liquid/condition.rb

@@ -3,19 +3,26 @@ module Liquid
   #
   # Example:
   #
-  #   c = Condition.new('1', '==', '1')
+  #   c = Condition.new(1, '==', 1)
   #   c.evaluate #=> true
   #
   class Condition #:nodoc:
     @@operators = {
-      '==' => lambda { |cond, left, right|  cond.send(:equal_variables, left, right) },
-      '!=' => lambda { |cond, left, right| !cond.send(:equal_variables, left, right) },
-      '<>' => lambda { |cond, left, right| !cond.send(:equal_variables, left, right) },
-      '<'  => :<,
-      '>'  => :>,
-      '>=' => :>=,
-      '<=' => :<=,
-      'contains' => lambda { |cond, left, right| left && right ? left.include?(right) : false }
+      '=='.freeze => ->(cond, left, right) {  cond.send(:equal_variables, left, right) },
+      '!='.freeze => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
+      '<>'.freeze => ->(cond, left, right) { !cond.send(:equal_variables, left, right) },
+      '<'.freeze  => :<,
+      '>'.freeze  => :>,
+      '>='.freeze => :>=,
+      '<='.freeze => :<=,
+      'contains'.freeze => lambda do |cond, left, right|
+        if left && right && left.respond_to?(:include?)
+          right = right.to_s if left.is_a?(String)
+          left.include?(right)
+        else
+          false
+        end
+      end
     }
 
     def self.operators
@@ -26,7 +33,9 @@ module Liquid
     attr_accessor :left, :operator, :right
 
     def initialize(left = nil, operator = nil, right = nil)
-      @left, @operator, @right = left, operator, right
+      @left = left
+      @operator = operator
+      @right = right
       @child_relation  = nil
       @child_condition = nil
     end
@@ -45,11 +54,13 @@ module Liquid
     end
 
     def or(condition)
-      @child_relation, @child_condition = :or, condition
+      @child_relation = :or
+      @child_condition = condition
     end
 
     def and(condition)
-      @child_relation, @child_condition = :and, condition
+      @child_relation = :and
+      @child_condition = condition
     end
 
     def attach(attachment)
@@ -61,23 +72,23 @@ module Liquid
     end
 
     def inspect
-      "#<Condition #{[@left, @operator, @right].compact.join(' ')}>"
+      "#<Condition #{[@left, @operator, @right].compact.join(' '.freeze)}>"
     end
 
     private
 
     def equal_variables(left, right)
-      if left.is_a?(Symbol)
-        if right.respond_to?(left)
-          return right.send(left.to_s)
+      if left.is_a?(Liquid::Expression::MethodLiteral)
+        if right.respond_to?(left.method_name)
+          return right.send(left.method_name)
         else
           return nil
         end
       end
 
-      if right.is_a?(Symbol)
-        if left.respond_to?(right)
-          return left.send(right.to_s)
+      if right.is_a?(Liquid::Expression::MethodLiteral)
+        if left.respond_to?(right.method_name)
+          return left.send(right.method_name)
         else
           return nil
         end
@@ -90,31 +101,32 @@ module Liquid
       # If the operator is empty this means that the decision statement is just
       # a single variable. We can just poll this variable from the context and
       # return this as the result.
-      return context[left] if op == nil
+      return context.evaluate(left) if op.nil?
 
-      left, right = context[left], context[right]
+      left = context.evaluate(left)
+      right = context.evaluate(right)
 
-      operation = self.class.operators[op] || raise(ArgumentError.new("Unknown operator #{op}"))
+      operation = self.class.operators[op] || raise(Liquid::ArgumentError.new("Unknown operator #{op}"))
 
       if operation.respond_to?(:call)
         operation.call(self, left, right)
-      elsif left.respond_to?(operation) and right.respond_to?(operation)
-        left.send(operation, right)
-      else
-        nil
+      elsif left.respond_to?(operation) && right.respond_to?(operation)
+        begin
+          left.send(operation, right)
+        rescue ::ArgumentError => e
+          raise Liquid::ArgumentError.new(e.message)
+        end
       end
     end
   end
 
-
   class ElseCondition < Condition
     def else?
       true
     end
 
-    def evaluate(context)
+    def evaluate(_context)
       true
     end
   end
-
 end

lib/liquid/context.rb

@@ -1,5 +1,4 @@
 module Liquid
-
   # Context keeps the variable stack and resolves variables, as well as keywords
   #
   #   context['variable'] = 'testing'
@@ -14,34 +13,26 @@ module Liquid
   #   context['bob']  #=> nil  class Context
   class Context
     attr_reader :scopes, :errors, :registers, :environments, :resource_limits
+    attr_accessor :exception_handler, :template_name
 
-    def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = {})
-      @environments    = [environments].flatten
-      @scopes          = [(outer_scope || {})]
-      @registers       = registers
-      @errors          = []
-      @rethrow_errors  = rethrow_errors
-      @resource_limits = (resource_limits || {}).merge!({ :render_score_current => 0, :assign_score_current => 0 })
+    def initialize(environments = {}, outer_scope = {}, registers = {}, rethrow_errors = false, resource_limits = nil)
+      @environments     = [environments].flatten
+      @scopes           = [(outer_scope || {})]
+      @registers        = registers
+      @errors           = []
+      @resource_limits  = resource_limits || ResourceLimits.new(Template.default_resource_limits)
       squash_instance_assigns_with_environments
 
+      @this_stack_used = false
+
+      if rethrow_errors
+        self.exception_handler = ->(e) { raise }
+      end
+
       @interrupts = []
       @filters = []
     end
 
-    def increment_used_resources(key, obj)
-      @resource_limits[key] += if obj.kind_of?(String) || obj.kind_of?(Array) || obj.kind_of?(Hash)
-        obj.length
-      else
-        1
-      end
-    end
-
-    def resource_limits_reached?
-      (@resource_limits[:render_length_limit] && @resource_limits[:render_length_current] > @resource_limits[:render_length_limit]) ||
-      (@resource_limits[:render_score_limit]  && @resource_limits[:render_score_current]  > @resource_limits[:render_score_limit] ) ||
-      (@resource_limits[:assign_score_limit]  && @resource_limits[:assign_score_current]  > @resource_limits[:assign_score_limit] )
-    end
-
     def strainer
       @strainer ||= Strainer.create(self, @filters)
     end
@@ -52,26 +43,13 @@ module Liquid
     # for that
     def add_filters(filters)
       filters = [filters].flatten.compact
-      filters.each do |f|
-        raise ArgumentError, "Expected module but got: #{f.class}" unless f.is_a?(Module)
-        Strainer.add_known_filter(f)
-      end
-
-      # If strainer is already setup then there's no choice but to use a runtime
-      # extend call. If strainer is not yet created, we can utilize strainers
-      # cached class based API, which avoids busting the method cache.
-      if @strainer
-        filters.each do |f|
-          strainer.extend(f)
-        end
-      else
-        @filters.concat filters
-      end
+      @filters += filters
+      @strainer = nil
     end
 
     # are there any not handled interrupts?
-    def has_interrupt?
-      @interrupts.any?
+    def interrupt?
+      !@interrupts.empty?
     end
 
     # push an interrupt to the stack. this interrupt is considered not handled.
@@ -84,26 +62,38 @@ module Liquid
       @interrupts.pop
     end
 
-    def handle_error(e)
-      errors.push(e)
-      raise if @rethrow_errors
-
-      case e
-      when SyntaxError
-        "Liquid syntax error: #{e.message}"
-      else
-        "Liquid error: #{e.message}"
+    def handle_error(e, token = nil)
+      if e.is_a?(Liquid::Error)
+        e.template_name = template_name
+        e.set_line_number_from_token(token)
       end
+
+      output = nil
+
+      if exception_handler
+        result = exception_handler.call(e)
+        case result
+        when Exception
+          e = result
+          e.set_line_number_from_token(token) if e.is_a?(Liquid::Error)
+        when String
+          output = result
+        else
+          raise if result
+        end
+      end
+      errors.push(e)
+      output || Liquid::Error.render(e)
     end
 
     def invoke(method, *args)
-      strainer.invoke(method, *args)
+      strainer.invoke(method, *args).to_liquid
     end
 
     # Push new local scope on the stack. use <tt>Context#stack</tt> instead
-    def push(new_scope={})
+    def push(new_scope = {})
       @scopes.unshift(new_scope)
-      raise StackLevelError, "Nesting too deep" if @scopes.length > 100
+      raise StackLevelError, "Nesting too deep".freeze if @scopes.length > 100
     end
 
     # Merge a hash of variables in the current local scope
@@ -125,11 +115,19 @@ module Liquid
     #   end
     #
     #   context['var]  #=> nil
-    def stack(new_scope={})
-      push(new_scope)
+    def stack(new_scope = nil)
+      old_stack_used = @this_stack_used
+      if new_scope
+        push(new_scope)
+        @this_stack_used = true
+      else
+        @this_stack_used = false
+      end
+
       yield
     ensure
-      pop
+      pop if @this_stack_used
+      @this_stack_used = old_stack_used
     end
 
     def clear_instance_assigns
@@ -138,148 +136,80 @@ module Liquid
 
     # Only allow String, Numeric, Hash, Array, Proc, Boolean or <tt>Liquid::Drop</tt>
     def []=(key, value)
+      unless @this_stack_used
+        @this_stack_used = true
+        push({})
+      end
       @scopes[0][key] = value
     end
 
-    def [](key)
-      resolve(key)
+    # Look up variable, either resolve directly after considering the name. We can directly handle
+    # Strings, digits, floats and booleans (true,false).
+    # If no match is made we lookup the variable in the current scope and
+    # later move up to the parent blocks to see if we can resolve the variable somewhere up the tree.
+    # Some special keywords return symbols. Those symbols are to be called on the rhs object in expressions
+    #
+    # Example:
+    #   products == empty #=> products.empty?
+    def [](expression)
+      evaluate(Expression.parse(expression))
     end
 
-    def has_key?(key)
-      resolve(key) != nil
+    def key?(key)
+      self[key] != nil
+    end
+
+    def evaluate(object)
+      object.respond_to?(:evaluate) ? object.evaluate(self) : object
+    end
+
+    # Fetches an object starting at the local scope and then moving up the hierachy
+    def find_variable(key)
+      # This was changed from find() to find_index() because this is a very hot
+      # path and find_index() is optimized in MRI to reduce object allocation
+      index = @scopes.find_index { |s| s.key?(key) }
+      scope = @scopes[index] if index
+
+      variable = nil
+
+      if scope.nil?
+        @environments.each do |e|
+          variable = lookup_and_evaluate(e, key)
+          unless variable.nil?
+            scope = e
+            break
+          end
+        end
+      end
+
+      scope ||= @environments.last || @scopes.last
+      variable ||= lookup_and_evaluate(scope, key)
+
+      variable = variable.to_liquid
+      variable.context = self if variable.respond_to?(:context=)
+
+      variable
+    end
+
+    def lookup_and_evaluate(obj, key)
+      if (value = obj[key]).is_a?(Proc) && obj.respond_to?(:[]=)
+        obj[key] = (value.arity == 0) ? value.call : value.call(self)
+      else
+        value
+      end
     end
 
     private
-      LITERALS = {
-        nil => nil, 'nil' => nil, 'null' => nil, '' => nil,
-        'true'  => true,
-        'false' => false,
-        'blank' => :blank?,
-        'empty' => :empty?
-      }
 
-      # Look up variable, either resolve directly after considering the name. We can directly handle
-      # Strings, digits, floats and booleans (true,false).
-      # If no match is made we lookup the variable in the current scope and
-      # later move up to the parent blocks to see if we can resolve the variable somewhere up the tree.
-      # Some special keywords return symbols. Those symbols are to be called on the rhs object in expressions
-      #
-      # Example:
-      #   products == empty #=> products.empty?
-      def resolve(key)
-        if LITERALS.key?(key)
-          LITERALS[key]
-        else
-          case key
-          when /\A'(.*)'\z/ # Single quoted strings
-            $1
-          when /\A"(.*)"\z/ # Double quoted strings
-            $1
-          when /\A(-?\d+)\z/ # Integer and floats
-            $1.to_i
-          when /\A\((\S+)\.\.(\S+)\)\z/ # Ranges
-            (resolve($1).to_i..resolve($2).to_i)
-          when /\A(-?\d[\d\.]+)\z/ # Floats
-            $1.to_f
-          else
-            variable(key)
+    def squash_instance_assigns_with_environments
+      @scopes.last.each_key do |k|
+        @environments.each do |env|
+          if env.key?(k)
+            scopes.last[k] = lookup_and_evaluate(env, k)
+            break
           end
         end
       end
-
-      # Fetches an object starting at the local scope and then moving up the hierachy
-      def find_variable(key)
-        scope = @scopes.find { |s| s.has_key?(key) }
-        variable = nil
-
-        if scope.nil?
-          @environments.each do |e|
-            if variable = lookup_and_evaluate(e, key)
-              scope = e
-              break
-            end
-          end
-        end
-
-        scope     ||= @environments.last || @scopes.last
-        variable  ||= lookup_and_evaluate(scope, key)
-
-        variable = variable.to_liquid
-        variable.context = self if variable.respond_to?(:context=)
-
-        return variable
-      end
-
-      # Resolves namespaced queries gracefully.
-      #
-      # Example
-      #  @context['hash'] = {"name" => 'tobi'}
-      #  assert_equal 'tobi', @context['hash.name']
-      #  assert_equal 'tobi', @context['hash["name"]']
-      def variable(markup)
-        parts = markup.scan(VariableParser)
-        square_bracketed = /\A\[(.*)\]\z/
-
-        first_part = parts.shift
-
-        if first_part =~ square_bracketed
-          first_part = resolve($1)
-        end
-
-        if object = find_variable(first_part)
-
-          parts.each do |part|
-            part = resolve($1) if part_resolved = (part =~ square_bracketed)
-
-            # If object is a hash- or array-like object we look for the
-            # presence of the key and if its available we return it
-            if object.respond_to?(:[]) and
-              ((object.respond_to?(:has_key?) and object.has_key?(part)) or
-               (object.respond_to?(:fetch) and part.is_a?(Integer)))
-
-              # if its a proc we will replace the entry with the proc
-              res = lookup_and_evaluate(object, part)
-              object = res.to_liquid
-
-              # Some special cases. If the part wasn't in square brackets and
-              # no key with the same name was found we interpret following calls
-              # as commands and call them on the current object
-            elsif !part_resolved and object.respond_to?(part) and ['size', 'first', 'last'].include?(part)
-
-              object = object.send(part.intern).to_liquid
-
-              # No key was present with the desired value and it wasn't one of the directly supported
-              # keywords either. The only thing we got left is to return nil
-            else
-              return nil
-            end
-
-            # If we are dealing with a drop here we have to
-            object.context = self if object.respond_to?(:context=)
-          end
-        end
-
-        object
-      end # variable
-
-      def lookup_and_evaluate(obj, key)
-        if (value = obj[key]).is_a?(Proc) && obj.respond_to?(:[]=)
-          obj[key] = (value.arity == 0) ? value.call : value.call(self)
-        else
-          value
-        end
-      end # lookup_and_evaluate
-
-      def squash_instance_assigns_with_environments
-        @scopes.last.each_key do |k|
-          @environments.each do |env|
-            if env.has_key?(k)
-              scopes.last[k] = lookup_and_evaluate(env, k)
-              break
-            end
-          end
-        end
-      end # squash_instance_assigns_with_environments
+    end # squash_instance_assigns_with_environments
   end # Context
-
 end # Liquid

lib/liquid/document.rb

@@ -1,18 +1,28 @@
 module Liquid
-  class Document < Block
-    # we don't need markup to open this block
-    def initialize(tokens, options = {})
-      @options = options
-      parse_body(tokens)
+  class Document < BlockBody
+    DEFAULT_OPTIONS = {
+      locale: I18n.new
+    }
+
+    def self.parse(tokens, options)
+      doc = new
+      doc.parse(tokens, DEFAULT_OPTIONS.merge(options))
+      doc
     end
 
-    # There isn't a real delimiter
-    def block_delimiter
-      nil
+    def parse(tokens, options)
+      super do |end_tag_name, end_tag_params|
+        unknown_tag(end_tag_name, options) if end_tag_name
+      end
     end
 
-    # Document blocks don't need to be terminated since they are not actually opened
-    def assert_missing_delimitation!
+    def unknown_tag(tag, options)
+      case tag
+      when 'else'.freeze, 'end'.freeze
+        raise SyntaxError.new(options[:locale].t("errors.syntax.unexpected_outer_tag".freeze, tag: tag))
+      else
+        raise SyntaxError.new(options[:locale].t("errors.syntax.unknown_tag".freeze, tag: tag))
+      end
     end
   end
 end

lib/liquid/drop.rb

@@ -1,7 +1,6 @@
 require 'set'
 
 module Liquid
-
   # A drop in liquid is a class which allows you to export DOM like things to liquid.
   # Methods of drops are callable.
   # The main use for liquid drops is to implement lazy loaded objects.
@@ -27,7 +26,7 @@ module Liquid
     EMPTY_STRING = ''.freeze
 
     # Catch all for the method
-    def before_method(method)
+    def before_method(_method)
       nil
     end
 
@@ -40,7 +39,7 @@ module Liquid
       end
     end
 
-    def has_key?(name)
+    def key?(_name)
       true
     end
 
@@ -56,12 +55,14 @@ module Liquid
       self.class.name
     end
 
-    alias :[] :invoke_drop
-
-    private
+    alias_method :[], :invoke_drop
 
     # Check for method existence without invoking respond_to?, which creates symbols
     def self.invokable?(method_name)
+      invokable_methods.include?(method_name.to_s)
+    end
+
+    def self.invokable_methods
       unless @invokable_methods
         blacklist = Liquid::Drop.public_instance_methods + [:each]
         if include?(Enumerable)
@@ -71,7 +72,7 @@ module Liquid
         whitelist = [:to_liquid] + (public_instance_methods - blacklist)
         @invokable_methods = Set.new(whitelist.map(&:to_s))
       end
-      @invokable_methods.include?(method_name.to_s)
+      @invokable_methods
     end
   end
 end

lib/liquid/errors.rb

@@ -1,12 +1,65 @@
 module Liquid
-  class Error < ::StandardError; end
+  class Error < ::StandardError
+    attr_accessor :line_number
+    attr_accessor :template_name
+    attr_accessor :markup_context
 
-  class ArgumentError < Error; end
-  class ContextError < Error; end
-  class FilterNotFound < Error; end
-  class FileSystemError < Error; end
-  class StandardError < Error; end
-  class SyntaxError < Error; end
-  class StackLevelError < Error; end
-  class MemoryError < Error; end
+    def to_s(with_prefix = true)
+      str = ""
+      str << message_prefix if with_prefix
+      str << super()
+
+      if markup_context
+        str << " "
+        str << markup_context
+      end
+
+      str
+    end
+
+    def set_line_number_from_token(token)
+      return unless token.respond_to?(:line_number)
+      return if line_number
+      self.line_number = token.line_number
+    end
+
+    def self.render(e)
+      if e.is_a?(Liquid::Error)
+        e.to_s
+      else
+        "Liquid error: #{e}"
+      end
+    end
+
+    private
+
+    def message_prefix
+      str = ""
+      if is_a?(SyntaxError)
+        str << "Liquid syntax error"
+      else
+        str << "Liquid error"
+      end
+
+      if line_number
+        str << " ("
+        str << template_name << " " if template_name
+        str << "line " << line_number.to_s << ")"
+      end
+
+      str << ": "
+      str
+    end
+  end
+
+  ArgumentError = Class.new(Error)
+  ContextError = Class.new(Error)
+  FileSystemError = Class.new(Error)
+  StandardError = Class.new(Error)
+  SyntaxError = Class.new(Error)
+  StackLevelError = Class.new(Error)
+  TaintedError = Class.new(Error)
+  MemoryError = Class.new(Error)
+  ZeroDivisionError = Class.new(Error)
+  FloatDomainError = Class.new(Error)
 end

lib/liquid/expression.rb

@@ -0,0 +1,45 @@
+module Liquid
+  class Expression
+    class MethodLiteral
+      attr_reader :method_name, :to_s
+
+      def initialize(method_name, to_s)
+        @method_name = method_name
+        @to_s = to_s
+      end
+
+      def to_liquid
+        to_s
+      end
+    end
+
+    LITERALS = {
+      nil => nil, 'nil'.freeze => nil, 'null'.freeze => nil, ''.freeze => nil,
+      'true'.freeze  => true,
+      'false'.freeze => false,
+      'blank'.freeze => MethodLiteral.new(:blank?, '').freeze,
+      'empty'.freeze => MethodLiteral.new(:empty?, '').freeze
+    }
+
+    def self.parse(markup)
+      if LITERALS.key?(markup)
+        LITERALS[markup]
+      else
+        case markup
+        when /\A'(.*)'\z/m # Single quoted strings
+          $1
+        when /\A"(.*)"\z/m # Double quoted strings
+          $1
+        when /\A(-?\d+)\z/ # Integer and floats
+          $1.to_i
+        when /\A\((\S+)\.\.(\S+)\)\z/ # Ranges
+          RangeLookup.parse($1, $2)
+        when /\A(-?\d[\d\.]+)\z/ # Floats
+          $1.to_f
+        else
+          VariableLookup.parse(markup)
+        end
+      end
+    end
+  end
+end

lib/liquid/file_system.rb

@@ -14,7 +14,7 @@ module Liquid
   # This will parse the template with a LocalFileSystem implementation rooted at 'template_path'.
   class BlankFileSystem
     # Called by Liquid to retrieve a template file
-    def read_template_file(template_path, context)
+    def read_template_file(_template_path)
       raise FileSystemError, "This liquid context does not allow includes."
     end
   end
@@ -44,14 +44,14 @@ module Liquid
   class LocalFileSystem
     attr_accessor :root
 
-    def initialize(root, pattern = "_%s.liquid")
+    def initialize(root, pattern = "_%s.liquid".freeze)
       @root = root
       @pattern = pattern
     end
 
-    def read_template_file(template_path, context)
+    def read_template_file(template_path)
       full_path = full_path(template_path)
-      raise FileSystemError, "No such template '#{template_path}'" unless File.exists?(full_path)
+      raise FileSystemError, "No such template '#{template_path}'" unless File.exist?(full_path)
 
       File.read(full_path)
     end
@@ -59,7 +59,7 @@ module Liquid
     def full_path(template_path)
       raise FileSystemError, "Illegal template name '#{template_path}'" unless template_path =~ /\A[^.\/][a-zA-Z0-9_\/]+\z/
 
-      full_path = if template_path.include?('/')
+      full_path = if template_path.include?('/'.freeze)
         File.join(root, File.dirname(template_path), @pattern % File.basename(template_path))
       else
         File.join(root, @pattern % template_path)

lib/liquid/htmltags.rb

@@ -1,74 +0,0 @@
-module Liquid
-  class TableRow < Block
-    Syntax = /(\w+)\s+in\s+(#{QuotedFragment}+)/o
-
-    def initialize(tag_name, markup, tokens)
-      if markup =~ Syntax
-        @variable_name = $1
-        @collection_name = $2
-        @attributes = {}
-        markup.scan(TagAttributes) do |key, value|
-          @attributes[key] = value
-        end
-      else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.table_row"))
-      end
-
-      super
-    end
-
-    def render(context)
-      collection = context[@collection_name] or return ''
-
-      from = @attributes['offset'] ? context[@attributes['offset']].to_i : 0
-      to = @attributes['limit'] ? from + context[@attributes['limit']].to_i : nil
-
-      collection = Utils.slice_collection(collection, from, to)
-
-      length = collection.length
-
-      cols = context[@attributes['cols']].to_i
-
-      row = 1
-      col = 0
-
-      result = "<tr class=\"row1\">\n"
-      context.stack do
-
-        collection.each_with_index do |item, index|
-          context[@variable_name] = item
-          context['tablerowloop'] = {
-            'length'  => length,
-            'index'   => index + 1,
-            'index0'  => index,
-            'col'     => col + 1,
-            'col0'    => col,
-            'index0'  => index,
-            'rindex'  => length - index,
-            'rindex0' => length - index - 1,
-            'first'   => (index == 0),
-            'last'    => (index == length - 1),
-            'col_first' => (col == 0),
-            'col_last'  => (col == cols - 1)
-          }
-
-
-          col += 1
-
-          result << "<td class=\"col#{col}\">" << super << '</td>'
-
-          if col == cols and (index != length - 1)
-            col  = 0
-            row += 1
-            result << "</tr>\n<tr class=\"row#{row}\">"
-          end
-
-        end
-      end
-      result << "</tr>\n"
-      result
-    end
-  end
-
-  Template.register_tag('tablerow', TableRow)
-end

lib/liquid/i18n.rb

@@ -2,11 +2,10 @@ require 'yaml'
 
 module Liquid
   class I18n
-    DEFAULT_LOCALE = File.join(File.expand_path(File.dirname(__FILE__)), "locales", "en.yml")
+    DEFAULT_LOCALE = File.join(File.expand_path(__dir__), "locales", "en.yml")
+
+    TranslationError = Class.new(StandardError)
 
-    class TranslationError < StandardError
-    end
-    
     attr_reader :path
 
     def initialize(path = DEFAULT_LOCALE)
@@ -23,15 +22,16 @@ module Liquid
     end
 
     private
+
     def interpolate(name, vars)
-      name.gsub(/%\{(\w+)\}/) {
+      name.gsub(/%\{(\w+)\}/) do
         # raise TranslationError, "Undefined key #{$1} for interpolation in translation #{name}"  unless vars[$1.to_sym]
         "#{vars[$1.to_sym]}"
-      }
+      end
     end
 
     def deep_fetch_translation(name)
-      name.split('.').reduce(locale) do |level, cur|
+      name.split('.'.freeze).reduce(locale) do |level, cur|
         level[cur] or raise TranslationError, "Translation for #{name} does not exist in locale #{path}"
       end
     end

lib/liquid/interrupts.rb

@@ -1,11 +1,10 @@
 module Liquid
-
   # An interrupt is any command that breaks processing of a block (ex: a for loop).
   class Interrupt
     attr_reader :message
 
-    def initialize(message=nil)
-      @message = message || "interrupt"
+    def initialize(message = nil)
+      @message = message || "interrupt".freeze
     end
   end
 

lib/liquid/lexer.rb

@@ -2,16 +2,18 @@ require "strscan"
 module Liquid
   class Lexer
     SPECIALS = {
-      '|' => :pipe,
-      '.' => :dot,
-      ':' => :colon,
-      ',' => :comma,
-      '[' => :open_square,
-      ']' => :close_square,
-      '(' => :open_round,
-      ')' => :close_round
+      '|'.freeze => :pipe,
+      '.'.freeze => :dot,
+      ':'.freeze => :colon,
+      ','.freeze => :comma,
+      '['.freeze => :open_square,
+      ']'.freeze => :close_square,
+      '('.freeze => :open_round,
+      ')'.freeze => :close_round,
+      '?'.freeze => :question,
+      '-'.freeze => :dash
     }
-    IDENTIFIER = /[\w\-?!]+/
+    IDENTIFIER = /[a-zA-Z_][\w-]*\??/
     SINGLE_STRING_LITERAL = /'[^\']*'/
     DOUBLE_STRING_LITERAL = /"[^\"]*"/
     NUMBER_LITERAL = /-?\d+(\.\d+)?/
@@ -25,7 +27,7 @@ module Liquid
     def tokenize
       @output = []
 
-      while !@ss.eos?
+      until @ss.eos?
         @ss.skip(/\s*/)
         tok = case
         when t = @ss.scan(COMPARISON_OPERATOR) then [:comparison, t]
@@ -37,7 +39,7 @@ module Liquid
         else
           c = @ss.getch
           if s = SPECIALS[c]
-            [s,c]
+            [s, c]
           else
             raise SyntaxError, "Unexpected character #{c}"
           end

lib/liquid/locales/en.yml

@@ -1,6 +1,7 @@
 ---
   errors:
     syntax:
+      tag_unexpected_args: "Syntax Error in '%{tag}' - Valid syntax: %{tag}"
       assign: "Syntax Error in 'assign' - Valid syntax: assign [var] = [source]"
       capture: "Syntax Error in 'capture' - Valid syntax: capture [var]"
       case: "Syntax Error in 'case' - Valid syntax: case [condition]"
@@ -14,7 +15,8 @@
       include: "Error in tag 'include' - Valid syntax: include '[template]' (with|for) [object|collection]"
       unknown_tag: "Unknown tag '%{tag}'"
       invalid_delimiter: "'end' is not a valid delimiter for %{block_name} tags. use %{block_delimiter}"
-      unexpected_else: "%{block_name} tag does not expect else tag"
+      unexpected_else: "%{block_name} tag does not expect 'else' tag"
+      unexpected_outer_tag: "Unexpected outer '%{tag}' tag"
       tag_termination: "Tag '%{token}' was not properly terminated with regexp: %{tag_end}"
       variable_termination: "Variable '%{token}' was not properly terminated with regexp: %{tag_end}"
       tag_never_closed: "'%{block_name}' tag was never closed"

lib/liquid/module_ex.rb

@@ -1,62 +0,0 @@
-# Copyright 2007 by Domizio Demichelis
-# This library is free software. It may be used, redistributed and/or modified
-# under the same terms as Ruby itself
-#
-# This extension is used in order to expose the object of the implementing class
-# to liquid as it were a Drop. It also limits the liquid-callable methods of the instance
-# to the allowed method passed with the liquid_methods call
-# Example:
-#
-# class SomeClass
-#   liquid_methods :an_allowed_method
-#
-#   def an_allowed_method
-#     'this comes from an allowed method'
-#   end
-#   def unallowed_method
-#     'this will never be an output'
-#   end
-# end
-#
-# if you want to extend the drop to other methods you can defines more methods
-# in the class <YourClass>::LiquidDropClass
-#
-#   class SomeClass::LiquidDropClass
-#     def another_allowed_method
-#       'and this from another allowed method'
-#     end
-#   end
-# end
-#
-# usage:
-# @something = SomeClass.new
-#
-# template:
-# {{something.an_allowed_method}}{{something.unallowed_method}} {{something.another_allowed_method}}
-#
-# output:
-# 'this comes from an allowed method and this from another allowed method'
-#
-# You can also chain associations, by adding the liquid_method call in the
-# association models.
-#
-class Module
-
-  def liquid_methods(*allowed_methods)
-    drop_class = eval "class #{self.to_s}::LiquidDropClass < Liquid::Drop; self; end"
-    define_method :to_liquid do
-      drop_class.new(self)
-    end
-    drop_class.class_eval do
-      def initialize(object)
-        @object = object
-      end
-      allowed_methods.each do |sym|
-        define_method sym do
-          @object.send sym
-        end
-      end
-    end
-  end
-
-end

lib/liquid/parser.rb

@@ -66,10 +66,11 @@ module Liquid
       str = ""
       # might be a keyword argument (identifier: expression)
       if look(:id) && look(:colon, 1)
-        str << consume << consume << ' '
+        str << consume << consume << ' '.freeze
       end
 
       str << expression
+      str
     end
 
     def variable_signature

lib/liquid/parser_switching.rb

@@ -0,0 +1,32 @@
+module Liquid
+  module ParserSwitching
+    def parse_with_selected_parser(markup)
+      case @options[:error_mode] || Template.error_mode
+      when :strict then strict_parse_with_error_context(markup)
+      when :lax    then lax_parse(markup)
+      when :warn
+        begin
+          return strict_parse_with_error_context(markup)
+        rescue SyntaxError => e
+          e.set_line_number_from_token(markup)
+          @warnings ||= []
+          @warnings << e
+          return lax_parse(markup)
+        end
+      end
+    end
+
+    private
+
+    def strict_parse_with_error_context(markup)
+      strict_parse(markup)
+    rescue SyntaxError => e
+      e.markup_context = markup_context(markup)
+      raise e
+    end
+
+    def markup_context(markup)
+      "in \"#{markup.strip}\""
+    end
+  end
+end

lib/liquid/profiler.rb

@@ -0,0 +1,158 @@
+require 'liquid/profiler/hooks'
+
+module Liquid
+  # Profiler enables support for profiling template rendering to help track down performance issues.
+  #
+  # To enable profiling, first require 'liquid/profiler'.
+  # Then, to profile a parse/render cycle, pass the <tt>profile: true</tt> option to <tt>Liquid::Template.parse</tt>.
+  # After <tt>Liquid::Template#render</tt> is called, the template object makes available an instance of this
+  # class via the <tt>Liquid::Template#profiler</tt> method.
+  #
+  #   template = Liquid::Template.parse(template_content, profile: true)
+  #   output  = template.render
+  #   profile = template.profiler
+  #
+  # This object contains all profiling information, containing information on what tags were rendered,
+  # where in the templates these tags live, and how long each tag took to render.
+  #
+  # This is a tree structure that is Enumerable all the way down, and keeps track of tags and rendering times
+  # inside of <tt>{% include %}</tt> tags.
+  #
+  #   profile.each do |node|
+  #     # Access to the token itself
+  #     node.code
+  #
+  #     # Which template and line number of this node.
+  #     # If top level, this will be "<root>".
+  #     node.partial
+  #     node.line_number
+  #
+  #     # Render time in seconds of this node
+  #     node.render_time
+  #
+  #     # If the template used {% include %}, this node will also have children.
+  #     node.children.each do |child2|
+  #       # ...
+  #     end
+  #   end
+  #
+  # Profiler also exposes the total time of the template's render in <tt>Liquid::Profiler#total_render_time</tt>.
+  #
+  # All render times are in seconds. There is a small performance hit when profiling is enabled.
+  #
+  class Profiler
+    include Enumerable
+
+    class Timing
+      attr_reader :code, :partial, :line_number, :children
+
+      def initialize(token, partial)
+        @code        = token.respond_to?(:raw) ? token.raw : token
+        @partial     = partial
+        @line_number = token.respond_to?(:line_number) ? token.line_number : nil
+        @children    = []
+      end
+
+      def self.start(token, partial)
+        new(token, partial).tap(&:start)
+      end
+
+      def start
+        @start_time = Time.now
+      end
+
+      def finish
+        @end_time = Time.now
+      end
+
+      def render_time
+        @end_time - @start_time
+      end
+    end
+
+    def self.profile_token_render(token)
+      if Profiler.current_profile && token.respond_to?(:render)
+        Profiler.current_profile.start_token(token)
+        output = yield
+        Profiler.current_profile.end_token(token)
+        output
+      else
+        yield
+      end
+    end
+
+    def self.profile_children(template_name)
+      if Profiler.current_profile
+        Profiler.current_profile.push_partial(template_name)
+        output = yield
+        Profiler.current_profile.pop_partial
+        output
+      else
+        yield
+      end
+    end
+
+    def self.current_profile
+      Thread.current[:liquid_profiler]
+    end
+
+    def initialize
+      @partial_stack = ["<root>"]
+
+      @root_timing = Timing.new("", current_partial)
+      @timing_stack = [@root_timing]
+
+      @render_start_at = Time.now
+      @render_end_at = @render_start_at
+    end
+
+    def start
+      Thread.current[:liquid_profiler] = self
+      @render_start_at = Time.now
+    end
+
+    def stop
+      Thread.current[:liquid_profiler] = nil
+      @render_end_at = Time.now
+    end
+
+    def total_render_time
+      @render_end_at - @render_start_at
+    end
+
+    def each(&block)
+      @root_timing.children.each(&block)
+    end
+
+    def [](idx)
+      @root_timing.children[idx]
+    end
+
+    def length
+      @root_timing.children.length
+    end
+
+    def start_token(token)
+      @timing_stack.push(Timing.start(token, current_partial))
+    end
+
+    def end_token(_token)
+      timing = @timing_stack.pop
+      timing.finish
+
+      @timing_stack.last.children << timing
+    end
+
+    def current_partial
+      @partial_stack.last
+    end
+
+    def push_partial(partial_name)
+      @partial_stack.push(partial_name)
+    end
+
+    def pop_partial
+      @partial_stack.pop
+    end
+  end
+end

lib/liquid/profiler/hooks.rb

@@ -0,0 +1,23 @@
+module Liquid
+  class BlockBody
+    def render_token_with_profiling(token, context)
+      Profiler.profile_token_render(token) do
+        render_token_without_profiling(token, context)
+      end
+    end
+
+    alias_method :render_token_without_profiling, :render_token
+    alias_method :render_token, :render_token_with_profiling
+  end
+
+  class Include < Tag
+    def render_with_profiling(context)
+      Profiler.profile_children(context.evaluate(@template_name_expr).to_s) do
+        render_without_profiling(context)
+      end
+    end
+
+    alias_method :render_without_profiling, :render
+    alias_method :render, :render_with_profiling
+  end
+end

lib/liquid/range_lookup.rb

@@ -0,0 +1,22 @@
+module Liquid
+  class RangeLookup
+    def self.parse(start_markup, end_markup)
+      start_obj = Expression.parse(start_markup)
+      end_obj = Expression.parse(end_markup)
+      if start_obj.respond_to?(:evaluate) || end_obj.respond_to?(:evaluate)
+        new(start_obj, end_obj)
+      else
+        start_obj.to_i..end_obj.to_i
+      end
+    end
+
+    def initialize(start_obj, end_obj)
+      @start_obj = start_obj
+      @end_obj = end_obj
+    end
+
+    def evaluate(context)
+      context.evaluate(@start_obj).to_i..context.evaluate(@end_obj).to_i
+    end
+  end
+end

lib/liquid/resource_limits.rb

@@ -0,0 +1,23 @@
+module Liquid
+  class ResourceLimits
+    attr_accessor :render_length, :render_score, :assign_score,
+      :render_length_limit, :render_score_limit, :assign_score_limit
+
+    def initialize(limits)
+      @render_length_limit = limits[:render_length_limit]
+      @render_score_limit = limits[:render_score_limit]
+      @assign_score_limit = limits[:assign_score_limit]
+      reset
+    end
+
+    def reached?
+      (@render_length_limit && @render_length > @render_length_limit) ||
+        (@render_score_limit && @render_score > @render_score_limit) ||
+        (@assign_score_limit && @assign_score > @assign_score_limit)
+    end
+
+    def reset
+      @render_length = @render_score = @assign_score = 0
+    end
+  end
+end

lib/liquid/standardfilters.rb

@@ -2,14 +2,18 @@ require 'cgi'
 require 'bigdecimal'
 
 module Liquid
-
   module StandardFilters
-    HTML_ESCAPE = { '&' => '&amp;',  '>' => '&gt;',   '<' => '&lt;', '"' => '&quot;', "'" => '&#39;' }
+    HTML_ESCAPE = {
+      '&'.freeze => '&amp;'.freeze,
+      '>'.freeze => '&gt;'.freeze,
+      '<'.freeze => '&lt;'.freeze,
+      '"'.freeze => '&quot;'.freeze,
+      "'".freeze => '&#39;'.freeze
+    }
     HTML_ESCAPE_ONCE_REGEXP = /["><']|&(?!([a-zA-Z]+|(#\d+));)/
 
     # Return the size of an array or of an string
     def size(input)
-
       input.respond_to?(:size) ? input.size : 0
     end
 
@@ -29,29 +33,45 @@ module Liquid
     end
 
     def escape(input)
-      CGI.escapeHTML(input) rescue input
+      CGI.escapeHTML(input).untaint rescue input
     end
+    alias_method :h, :escape
 
     def escape_once(input)
       input.to_s.gsub(HTML_ESCAPE_ONCE_REGEXP, HTML_ESCAPE)
     end
 
-    alias_method :h, :escape
-
-    # Truncate a string down to x characters
-    def truncate(input, length = 50, truncate_string = "...")
-      if input.nil? then return end
-      l = length.to_i - truncate_string.length
-      l = 0 if l < 0
-      input.length > length.to_i ? input[0...l] + truncate_string : input
+    def url_encode(input)
+      CGI.escape(input) rescue input
     end
 
-    def truncatewords(input, words = 15, truncate_string = "...")
-      if input.nil? then return end
-      wordlist = input.to_s.split
-      l = words.to_i - 1
+    def slice(input, offset, length = nil)
+      offset = to_integer(offset)
+      length = length ? to_integer(length) : 1
+
+      if input.is_a?(Array)
+        input.slice(offset, length) || []
+      else
+        input.to_s.slice(offset, length) || ''
+      end
+    end
+
+    # Truncate a string down to x characters
+    def truncate(input, length = 50, truncate_string = "...".freeze)
+      return if input.nil?
+      length = to_integer(length)
+      l = length - truncate_string.length
       l = 0 if l < 0
-      wordlist.length > l ? wordlist[0..l].join(" ") + truncate_string : input
+      input.length > length ? input[0...l] + truncate_string : input
+    end
+
+    def truncatewords(input, words = 15, truncate_string = "...".freeze)
+      return if input.nil?
+      wordlist = input.to_s.split
+      words = to_integer(words)
+      l = words - 1
+      l = 0 if l < 0
+      wordlist.length > l ? wordlist[0..l].join(" ".freeze) + truncate_string : input
     end
 
     # Split input string into an array of substrings separated by given pattern.
@@ -60,7 +80,7 @@ module Liquid
     #   <div class="summary">{{ post | split '//' | first }}</div>
     #
     def split(input, pattern)
-      input.split(pattern)
+      input.to_s.split(pattern)
     end
 
     def strip(input)
@@ -76,44 +96,76 @@ module Liquid
     end
 
     def strip_html(input)
-      input.to_s.gsub(/<script.*?<\/script>/m, '').gsub(/<!--.*?-->/m, '').gsub(/<style.*?<\/style>/m, '').gsub(/<.*?>/m, '')
+      empty = ''.freeze
+      input.to_s.gsub(/<script.*?<\/script>/m, empty).gsub(/<!--.*?-->/m, empty).gsub(/<style.*?<\/style>/m, empty).gsub(/<.*?>/m, empty)
     end
 
     # Remove all newlines from the string
     def strip_newlines(input)
-      input.to_s.gsub(/\r?\n/, '')
+      input.to_s.gsub(/\r?\n/, ''.freeze)
+    end
+
+    # Remove whitespace between HTML tags
+    def strip_html_whitespace(input)
+      Spaceless.strip_html_whitespace(input.to_s)
     end
 
     # Join elements of the array with certain character between them
-    def join(input, glue = ' ')
-      [input].flatten.join(glue)
+    def join(input, glue = ' '.freeze)
+      InputIterator.new(input).join(glue)
     end
 
     # Sort elements of the array
     # provide optional property with which to sort an array of hashes or drops
     def sort(input, property = nil)
-      ary = flatten_if_necessary(input)
+      ary = InputIterator.new(input)
       if property.nil?
         ary.sort
-      elsif ary.first.respond_to?('[]') and !ary.first[property].nil?
-        ary.sort {|a,b| a[property] <=> b[property] }
+      elsif ary.first.respond_to?(:[]) && !ary.first[property].nil?
+        ary.sort { |a, b| a[property] <=> b[property] }
       elsif ary.first.respond_to?(property)
-        ary.sort {|a,b| a.send(property) <=> b.send(property) }
+        ary.sort { |a, b| a.send(property) <=> b.send(property) }
+      end
+    end
+
+    # Sort elements of an array ignoring case if strings
+    # provide optional property with which to sort an array of hashes or drops
+    def sort_natural(input, property = nil)
+      ary = InputIterator.new(input)
+
+      if property.nil?
+        ary.sort { |a, b| a.casecmp(b) }
+      elsif ary.first.respond_to?(:[]) && !ary.first[property].nil?
+        ary.sort { |a, b| a[property].casecmp(b[property]) }
+      elsif ary.first.respond_to?(property)
+        ary.sort { |a, b| a.send(property).casecmp(b.send(property)) }
+      end
+    end
+
+    # Remove duplicate elements from an array
+    # provide optional property with which to determine uniqueness
+    def uniq(input, property = nil)
+      ary = InputIterator.new(input)
+
+      if property.nil?
+        ary.uniq
+      elsif ary.first.respond_to?(:[])
+        ary.uniq{ |a| a[property] }
       end
     end
 
     # Reverse the elements of an array
     def reverse(input)
-      ary = [input].flatten
+      ary = InputIterator.new(input)
       ary.reverse
     end
 
     # map/collect on a given property
     def map(input, property)
-      flatten_if_necessary(input).map do |e|
+      InputIterator.new(input).map do |e|
         e = e.call if e.is_a?(Proc)
 
-        if property == "to_liquid"
+        if property == "to_liquid".freeze
           e
         elsif e.respond_to?(:[])
           e[property]
@@ -121,24 +173,38 @@ module Liquid
       end
     end
 
+    # Remove nils within an array
+    # provide optional property with which to check for nil
+    def compact(input, property = nil)
+      ary = InputIterator.new(input)
+
+      if property.nil?
+        ary.compact
+      elsif ary.first.respond_to?(:[])
+        ary.reject{ |a| a[property].nil? }
+      elsif ary.first.respond_to?(property)
+        ary.reject { |a| a.send(property).nil? }
+      end
+    end
+
     # Replace occurrences of a string with another
-    def replace(input, string, replacement = '')
-      input.to_s.gsub(string, replacement.to_s)
+    def replace(input, string, replacement = ''.freeze)
+      input.to_s.gsub(string.to_s, replacement.to_s)
     end
 
     # Replace the first occurrences of a string with another
-    def replace_first(input, string, replacement = '')
-      input.to_s.sub(string, replacement.to_s)
+    def replace_first(input, string, replacement = ''.freeze)
+      input.to_s.sub(string.to_s, replacement.to_s)
     end
 
     # remove a substring
     def remove(input, string)
-      input.to_s.gsub(string, '')
+      input.to_s.gsub(string.to_s, ''.freeze)
     end
 
     # remove the first occurrences of a substring
     def remove_first(input, string)
-      input.to_s.sub(string, '')
+      input.to_s.sub(string.to_s, ''.freeze)
     end
 
     # add one string to another
@@ -146,6 +212,10 @@ module Liquid
       input.to_s + string.to_s
     end
 
+    def concat(input, array)
+      InputIterator.new(input).concat(array)
+    end
+
     # prepend a string to another
     def prepend(input, string)
       string.to_s + input.to_s
@@ -153,10 +223,10 @@ module Liquid
 
     # Add <br /> tags in front of all newlines in input string
     def newline_to_br(input)
-      input.to_s.gsub(/\n/, "<br />\n")
+      input.to_s.gsub(/\n/, "<br />\n".freeze)
     end
 
-    # Reformat a date
+    # Reformat a date using Ruby's core Time#strftime( string ) -> string
     #
     #   %a - The abbreviated weekday name (``Sun'')
     #   %A - The  full  weekday  name (``Sunday'')
@@ -170,6 +240,7 @@ module Liquid
     #   %m - Month of the year (01..12)
     #   %M - Minute of the hour (00..59)
     #   %p - Meridian indicator (``AM''  or  ``PM'')
+    #   %s - Number of seconds since 1970-01-01 00:00:00 UTC.
     #   %S - Second of the minute (00..60)
     #   %U - Week  number  of the current year,
     #           starting with the first Sunday as the first
@@ -184,34 +255,14 @@ module Liquid
     #   %Y - Year with century
     #   %Z - Time zone name
     #   %% - Literal ``%'' character
+    #
+    #   See also: http://www.ruby-doc.org/core/Time.html#method-i-strftime
     def date(input, format)
+      return input if format.to_s.empty?
 
-      if format.to_s.empty?
-        return input.to_s
-      end
+      return input unless date = to_date(input)
 
-      if ((input.is_a?(String) && !/\A\d+\z/.match(input.to_s).nil?) || input.is_a?(Integer)) && input.to_i > 0
-        input = Time.at(input.to_i)
-      end
-
-      date = if input.is_a?(String)
-        case input.downcase
-        when 'now', 'today'
-          Time.now
-        else
-          Time.parse(input)
-        end
-      else
-        input
-      end
-
-      if date.respond_to?(:strftime)
-        date.strftime(format.to_s)
-      else
-        input
-      end
-    rescue
-      input
+      date.strftime(format.to_s)
     end
 
     # Get the first element of the passed in array
@@ -250,28 +301,52 @@ module Liquid
     # division
     def divided_by(input, operand)
       apply_operation(input, operand, :/)
+    rescue ::ZeroDivisionError => e
+      raise Liquid::ZeroDivisionError, e.message
     end
 
     def modulo(input, operand)
       apply_operation(input, operand, :%)
+    rescue ::ZeroDivisionError => e
+      raise Liquid::ZeroDivisionError, e.message
     end
 
-    def default(input, default_value = "")
+    def round(input, n = 0)
+      result = to_number(input).round(to_number(n))
+      result = result.to_f if result.is_a?(BigDecimal)
+      result = result.to_i if n == 0
+      result
+    rescue ::FloatDomainError => e
+      raise Liquid::FloatDomainError, e.message
+    end
+
+    def ceil(input)
+      to_number(input).ceil.to_i
+    rescue ::FloatDomainError => e
+      raise Liquid::FloatDomainError, e.message
+    end
+
+    def floor(input)
+      to_number(input).floor.to_i
+    rescue ::FloatDomainError => e
+      raise Liquid::FloatDomainError, e.message
+    end
+
+    def default(input, default_value = "".freeze)
       is_blank = input.respond_to?(:empty?) ? input.empty? : !input
       is_blank ? default_value : input
     end
 
     private
 
-    def flatten_if_necessary(input)
-      ary = if input.is_a?(Array)
-        input.flatten
-      elsif input.is_a?(Enumerable) && !input.is_a?(Hash)
-        input
-      else
-        [input].flatten
+    def to_integer(num)
+      return num if num.is_a?(Integer)
+      num = num.to_s
+      begin
+        Integer(num)
+      rescue ::ArgumentError
+        raise Liquid::ArgumentError, "invalid integer"
       end
-      ary.map{ |e| e.respond_to?(:to_liquid) ? e.to_liquid : e }
     end
 
     def to_number(obj)
@@ -287,10 +362,72 @@ module Liquid
       end
     end
 
+    def to_date(obj)
+      return obj if obj.respond_to?(:strftime)
+
+      if obj.is_a?(String)
+        return nil if obj.empty?
+        obj = obj.downcase
+      end
+
+      case obj
+      when 'now'.freeze, 'today'.freeze
+        Time.now
+      when /\A\d+\z/, Integer
+        Time.at(obj.to_i)
+      when String
+        Time.parse(obj)
+      end
+    rescue ArgumentError
+      nil
+    end
+
     def apply_operation(input, operand, operation)
       result = to_number(input).send(operation, to_number(operand))
       result.is_a?(BigDecimal) ? result.to_f : result
     end
+
+    class InputIterator
+      include Enumerable
+
+      def initialize(input)
+        @input = if input.is_a?(Array)
+          input.flatten
+        elsif input.is_a?(Hash)
+          [input]
+        elsif input.is_a?(Enumerable)
+          input
+        else
+          Array(input)
+        end
+      end
+
+      def join(glue)
+        to_a.join(glue)
+      end
+
+      def concat(args)
+        to_a.concat args
+      end
+
+      def reverse
+        reverse_each.to_a
+      end
+
+      def uniq(&block)
+        to_a.uniq(&block)
+      end
+
+      def compact
+        to_a.compact
+      end
+
+      def each
+        @input.each do |e|
+          yield(e.respond_to?(:to_liquid) ? e.to_liquid : e)
+        end
+      end
+    end
   end
 
   Template.register_filter(StandardFilters)

lib/liquid/strainer.rb

@@ -1,19 +1,19 @@
 require 'set'
 
 module Liquid
-
   # Strainer is the parent class for the filters system.
   # New filters are mixed into the strainer class which is then instantiated for each liquid template render run.
   #
   # The Strainer only allows method calls defined in filters given to it via Strainer.global_filter,
   # Context#add_filters or Template.register_filter
   class Strainer #:nodoc:
-    @@filters = []
-    @@known_filters = Set.new
-    @@known_methods = Set.new
+    @@global_strainer = Class.new(Strainer) do
+      @filter_methods = Set.new
+    end
     @@strainer_class_cache = Hash.new do |hash, filters|
-      hash[filters] = Class.new(Strainer) do
-        filters.each { |f| include f }
+      hash[filters] = Class.new(@@global_strainer) do
+        @filter_methods = @@global_strainer.filter_methods.dup
+        filters.each { |f| add_filter(f) }
       end
     end
 
@@ -21,33 +21,32 @@ module Liquid
       @context = context
     end
 
-    def self.global_filter(filter)
-      raise ArgumentError, "Passed filter is not a module" unless filter.is_a?(Module)
-      add_known_filter(filter)
-      @@filters << filter unless @@filters.include?(filter)
+    class << self
+      attr_reader :filter_methods
     end
 
-    def self.add_known_filter(filter)
-      unless @@known_filters.include?(filter)
-        @@method_blacklist ||= Set.new(Strainer.instance_methods.map(&:to_s))
-        new_methods = filter.instance_methods.map(&:to_s)
-        new_methods.reject!{ |m| @@method_blacklist.include?(m) }
-        @@known_methods.merge(new_methods)
-        @@known_filters.add(filter)
+    def self.add_filter(filter)
+      raise ArgumentError, "Expected module but got: #{f.class}" unless filter.is_a?(Module)
+      unless self.class.include?(filter)
+        send(:include, filter)
+        @filter_methods.merge(filter.public_instance_methods.map(&:to_s))
       end
     end
 
-    def self.strainer_class_cache
-      @@strainer_class_cache
+    def self.global_filter(filter)
+      @@global_strainer.add_filter(filter)
+    end
+
+    def self.invokable?(method)
+      @filter_methods.include?(method.to_s)
     end
 
     def self.create(context, filters = [])
-      filters = @@filters + filters
-      strainer_class_cache[filters].new(context)
+      @@strainer_class_cache[filters].new(context)
     end
 
     def invoke(method, *args)
-      if invokable?(method)
+      if self.class.invokable?(method)
         send(method, *args)
       else
         args.first
@@ -55,9 +54,5 @@ module Liquid
     rescue ::ArgumentError => e
       raise Liquid::ArgumentError.new(e.message)
     end
-
-    def invokable?(method)
-      @@known_methods.include?(method.to_s) && respond_to?(method)
-    end
   end
 end

lib/liquid/tag.rb

@@ -1,56 +1,42 @@
 module Liquid
   class Tag
-    attr_accessor :options
+    attr_accessor :options, :line_number
     attr_reader :nodelist, :warnings
+    include ParserSwitching
 
-    def self.new_with_options(tag_name, markup, tokens, options)
-      # Forgive me Matz for I have sinned. I know this code is weird
-      # but it was necessary to maintain API compatibility.
-      new_tag = self.allocate
-      new_tag.options = options
-      new_tag.send(:initialize, tag_name, markup, tokens)
-      new_tag
+    class << self
+      def parse(tag_name, markup, tokens, options)
+        tag = new(tag_name, markup, options)
+        tag.parse(tokens)
+        tag
+      end
+
+      private :new
     end
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
       @tag_name   = tag_name
       @markup     = markup
-      @options    ||= {} # needs || because might be set before initialize
+      @options    = options
+    end
+
+    def parse(_tokens)
+    end
+
+    def raw
+      "#{@tag_name} #{@markup}"
     end
 
     def name
       self.class.name.downcase
     end
 
-    def render(context)
-      ''
+    def render(_context)
+      ''.freeze
     end
 
     def blank?
-      @blank || false
+      false
     end
-
-    def parse_with_selected_parser(markup)
-      case @options[:error_mode] || Template.error_mode
-      when :strict then strict_parse_with_error_context(markup)
-      when :lax    then lax_parse(markup)
-      when :warn
-        begin
-          return strict_parse_with_error_context(markup)
-        rescue SyntaxError => e
-          @warnings ||= []
-          @warnings << e
-          return lax_parse(markup)
-        end
-      end
-    end
-
-    private
-    def strict_parse_with_error_context(markup)
-      strict_parse(markup)
-    rescue SyntaxError => e
-      e.message << " in \"#{markup.strip}\"" 
-      raise e
-    end
-  end # Tag
-end # Liquid
+  end
+end

lib/liquid/tags/assign.rb

@@ -1,5 +1,4 @@
 module Liquid
-
   # Assign sets a variable in your template.
   #
   #   {% assign foo = 'monkey' %}
@@ -9,24 +8,27 @@ module Liquid
   #  {{ foo }}
   #
   class Assign < Tag
-    Syntax = /(#{VariableSignature}+)\s*=\s*(.*)\s*/o
+    Syntax = /(#{VariableSignature}+)\s*=\s*(.*)\s*/om
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
       if markup =~ Syntax
         @to = $1
-        @from = Variable.new($2)
+        @from = Variable.new($2, options)
+        @from.line_number = line_number
       else
-        raise SyntaxError.new options[:locale].t("errors.syntax.assign")
+        raise SyntaxError.new options[:locale].t("errors.syntax.assign".freeze)
       end
-
-      super
     end
 
     def render(context)
       val = @from.render(context)
       context.scopes.last[@to] = val
-      context.increment_used_resources(:assign_score_current, val)
-      ''
+
+      inc = val.instance_of?(String) || val.instance_of?(Array) || val.instance_of?(Hash) ? val.length : 1
+      context.resource_limits.assign_score += inc
+
+      ''.freeze
     end
 
     def blank?
@@ -34,5 +36,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('assign', Assign)
+  Template.register_tag('assign'.freeze, Assign)
 end

lib/liquid/tags/break.rb

@@ -1,5 +1,4 @@
 module Liquid
-
   # Break tag to be used to break out of a for loop.
   #
   # == Basic Usage:
@@ -10,12 +9,10 @@ module Liquid
   #    {% endfor %}
   #
   class Break < Tag
-
     def interrupt
       BreakInterrupt.new
     end
-
   end
 
-  Template.register_tag('break', Break)
+  Template.register_tag('break'.freeze, Break)
 end

lib/liquid/tags/capture.rb

@@ -1,5 +1,4 @@
 module Liquid
-
   # Capture stores the result of a block into a variable without rendering it inplace.
   #
   #   {% capture heading %}
@@ -12,23 +11,22 @@ module Liquid
   # in a sidebar or footer.
   #
   class Capture < Block
-    Syntax = /(\w+)/
+    Syntax = /(#{VariableSignature}+)/o
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
       if markup =~ Syntax
         @to = $1
       else
         raise SyntaxError.new(options[:locale].t("errors.syntax.capture"))
       end
-
-      super
     end
 
     def render(context)
       output = super
       context.scopes.last[@to] = output
-      context.increment_used_resources(:assign_score_current, output)
-      ''
+      context.resource_limits.assign_score += output.length
+      ''.freeze
     end
 
     def blank?
@@ -36,5 +34,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('capture', Capture)
+  Template.register_tag('capture'.freeze, Capture)
 end

lib/liquid/tags/case.rb

@@ -1,30 +1,35 @@
 module Liquid
   class Case < Block
     Syntax     = /(#{QuotedFragment})/o
-    WhenSyntax = /(#{QuotedFragment})(?:(?:\s+or\s+|\s*\,\s*)(#{QuotedFragment}.*))?/o
+    WhenSyntax = /(#{QuotedFragment})(?:(?:\s+or\s+|\s*\,\s*)(#{QuotedFragment}.*))?/om
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
       @blocks = []
 
       if markup =~ Syntax
-        @left = $1
+        @left = Expression.parse($1)
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.case"))
+        raise SyntaxError.new(options[:locale].t("errors.syntax.case".freeze))
       end
+    end
 
-      super
+    def parse(tokens)
+      body = BlockBody.new
+      while parse_body(body, tokens)
+        body = @blocks.last.attachment
+      end
     end
 
     def nodelist
-      @blocks.map(&:attachment).flatten
+      @blocks.map(&:attachment)
     end
 
     def unknown_tag(tag, markup, tokens)
-      @nodelist = []
       case tag
-      when 'when'
+      when 'when'.freeze
         record_when_condition(markup)
-      when 'else'
+      when 'else'.freeze
         record_else_condition(markup)
       else
         super
@@ -38,10 +43,10 @@ module Liquid
         output = ''
         @blocks.each do |block|
           if block.else?
-            return render_all(block.attachment, context) if execute_else_block
+            return block.attachment.render(context) if execute_else_block
           elsif block.evaluate(context)
             execute_else_block = false
-            output << render_all(block.attachment, context)
+            output << block.attachment.render(context)
           end
         end
         output
@@ -51,30 +56,31 @@ module Liquid
     private
 
     def record_when_condition(markup)
+      body = BlockBody.new
+
       while markup
-        # Create a new nodelist and assign it to the new block
-        if not markup =~ WhenSyntax
-          raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_when"))
+        unless markup =~ WhenSyntax
+          raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_when".freeze))
         end
 
         markup = $2
 
-        block = Condition.new(@left, '==', $1)
-        block.attach(@nodelist)
-        @blocks.push(block)
+        block = Condition.new(@left, '=='.freeze, Expression.parse($1))
+        block.attach(body)
+        @blocks << block
       end
     end
 
     def record_else_condition(markup)
-      if not markup.strip.empty?
-        raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_else"))
+      unless markup.strip.empty?
+        raise SyntaxError.new(options[:locale].t("errors.syntax.case_invalid_else".freeze))
       end
 
       block = ElseCondition.new
-      block.attach(@nodelist)
+      block.attach(BlockBody.new)
       @blocks << block
     end
   end
 
-  Template.register_tag('case', Case)
+  Template.register_tag('case'.freeze, Case)
 end

lib/liquid/tags/comment.rb

@@ -1,10 +1,10 @@
 module Liquid
   class Comment < Block
-    def render(context)
-      ''
+    def render(_context)
+      ''.freeze
     end
 
-    def unknown_tag(tag, markup, tokens)
+    def unknown_tag(_tag, _markup, _tokens)
     end
 
     def blank?
@@ -12,5 +12,5 @@ module Liquid
     end
   end
 
-  Template.register_tag('comment', Comment)
+  Template.register_tag('comment'.freeze, Comment)
 end

lib/liquid/tags/continue.rb

@@ -1,5 +1,4 @@
 module Liquid
-
   # Continue tag to be used to break out of a for loop.
   #
   # == Basic Usage:
@@ -10,12 +9,10 @@ module Liquid
   #    {% endfor %}
   #
   class Continue < Tag
-
     def interrupt
       ContinueInterrupt.new
     end
-
   end
 
-  Template.register_tag('continue', Continue)
+  Template.register_tag('continue'.freeze, Continue)
 end

lib/liquid/tags/cycle.rb

@@ -13,29 +13,29 @@ module Liquid
   #
   class Cycle < Tag
     SimpleSyntax = /\A#{QuotedFragment}+/o
-    NamedSyntax  = /\A(#{QuotedFragment})\s*\:\s*(.*)/o
+    NamedSyntax  = /\A(#{QuotedFragment})\s*\:\s*(.*)/om
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
       case markup
       when NamedSyntax
         @variables = variables_from_string($2)
-        @name = $1
+        @name = Expression.parse($1)
       when SimpleSyntax
         @variables = variables_from_string(markup)
-        @name = "'#{@variables.to_s}'"
+        @name = @variables.to_s
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.cycle"))
+        raise SyntaxError.new(options[:locale].t("errors.syntax.cycle".freeze))
       end
-      super
     end
 
     def render(context)
       context.registers[:cycle] ||= Hash.new(0)
 
       context.stack do
-        key = context[@name]
+        key = context.evaluate(@name)
         iteration = context.registers[:cycle][key]
-        result = context[@variables[iteration]]
+        result = context.evaluate(@variables[iteration])
         iteration += 1
         iteration  = 0  if iteration >= @variables.size
         context.registers[:cycle][key] = iteration
@@ -43,15 +43,12 @@ module Liquid
       end
     end
 
-    def blank?
-      false
-    end
-
     private
+
     def variables_from_string(markup)
       markup.split(',').collect do |var|
         var =~ /\s*(#{QuotedFragment})\s*/o
-        $1 ? $1 : nil
+        $1 ? Expression.parse($1) : nil
       end.compact
     end
   end

lib/liquid/tags/decrement.rb

@@ -1,5 +1,4 @@
 module Liquid
-
   # decrement is used in a place where one needs to insert a counter
   #     into a template, and needs the counter to survive across
   #     multiple instantiations of the template.
@@ -19,21 +18,18 @@ module Liquid
   #    Hello: -3
   #
   class Decrement < Tag
-    def initialize(tag_name, markup, tokens)
-      @variable = markup.strip
-
+    def initialize(tag_name, markup, options)
       super
+      @variable = markup.strip
     end
 
     def render(context)
       value = context.environments.first[@variable] ||= 0
-      value = value - 1
+      value -= 1
       context.environments.first[@variable] = value
       value.to_s
     end
-
-    private
   end
 
-  Template.register_tag('decrement', Decrement)
+  Template.register_tag('decrement'.freeze, Decrement)
 end

lib/liquid/tags/for.rb

@@ -1,5 +1,4 @@
 module Liquid
-
   # "For" iterates over an array or collection.
   # Several useful variables are available to you within the loop.
   #
@@ -42,45 +41,48 @@ module Liquid
   #                   where 0 is the last item.
   # forloop.first:: Returns true if the item is the first item.
   # forloop.last:: Returns true if the item is the last item.
+  # forloop.parentloop:: Provides access to the parent loop, if present.
   #
   class For < Block
     Syntax = /\A(#{VariableSegment}+)\s+in\s+(#{QuotedFragment}+)\s*(reversed)?/o
 
-    def initialize(tag_name, markup, tokens)
-      parse_with_selected_parser(markup)
-      @nodelist = @for_block = []
+    def initialize(tag_name, markup, options)
       super
+      parse_with_selected_parser(markup)
+      @for_block = BlockBody.new
+    end
+
+    def parse(tokens)
+      return unless parse_body(@for_block, tokens)
+      parse_body(@else_block, tokens)
     end
 
     def nodelist
-      if @else_block
-        @for_block + @else_block
-      else
-        @for_block
-      end
+      @else_block ? [@for_block, @else_block] : [@for_block]
     end
 
     def unknown_tag(tag, markup, tokens)
-      return super unless tag == 'else'
-      @nodelist = @else_block = []
+      return super unless tag == 'else'.freeze
+      @else_block = BlockBody.new
     end
 
     def render(context)
-      context.registers[:for] ||= Hash.new(0)
+      for_offsets = context.registers[:for] ||= Hash.new(0)
+      for_stack = context.registers[:for_stack] ||= []
 
-      collection = context[@collection_name]
+      parent_loop = for_stack.last
+      for_stack.push(nil)
+
+      collection = context.evaluate(@collection_name)
       collection = collection.to_a if collection.is_a?(Range)
 
-      # Maintains Ruby 1.8.7 String#each behaviour on 1.9
-      return render_else(context) unless iterable?(collection)
-
-      from = if @attributes['offset'] == 'continue'
-        context.registers[:for][@name].to_i
+      from = if @from == :continue
+        for_offsets[@name].to_i
       else
-        context[@attributes['offset']].to_i
+        context.evaluate(@from).to_i
       end
 
-      limit = context[@attributes['limit']]
+      limit = context.evaluate(@limit)
       to    = limit ? limit.to_i + from : nil
 
       segment = Utils.slice_collection(collection, from, to)
@@ -94,32 +96,40 @@ module Liquid
       length = segment.length
 
       # Store our progress through the collection for the continue flag
-      context.registers[:for][@name] = from + segment.length
+      for_offsets[@name] = from + segment.length
 
       context.stack do
         segment.each_with_index do |item, index|
           context[@variable_name] = item
-          context['forloop'] = {
-            'name'    => @name,
-            'length'  => length,
-            'index'   => index + 1,
-            'index0'  => index,
-            'rindex'  => length - index,
-            'rindex0' => length - index - 1,
-            'first'   => (index == 0),
-          'last'    => (index == length - 1) }
+          loop_vars = {
+            'name'.freeze       => @name,
+            'length'.freeze     => length,
+            'index'.freeze      => index + 1,
+            'index0'.freeze     => index,
+            'rindex'.freeze     => length - index,
+            'rindex0'.freeze    => length - index - 1,
+            'first'.freeze      => (index == 0),
+            'last'.freeze       => (index == length - 1),
+            'parentloop'.freeze => parent_loop
+          }
 
-          result << render_all(@for_block, context)
+          context['forloop'.freeze] = loop_vars
+          for_stack[-1] = loop_vars
+
+          result << @for_block.render(context)
 
           # Handle any interrupts if they exist.
-          if context.has_interrupt?
+          if context.interrupt?
             interrupt = context.pop_interrupt
             break if interrupt.is_a? BreakInterrupt
             next if interrupt.is_a? ContinueInterrupt
           end
         end
       end
+
       result
+    ensure
+      for_stack.pop
     end
 
     protected
@@ -127,48 +137,56 @@ module Liquid
     def lax_parse(markup)
       if markup =~ Syntax
         @variable_name = $1
-        @collection_name = $2
-        @name = "#{$1}-#{$2}"
-        @reversed = $3
-        @attributes = {}
+        collection_name = $2
+        @reversed = !!$3
+        @name = "#{@variable_name}-#{collection_name}"
+        @collection_name = Expression.parse(collection_name)
         markup.scan(TagAttributes) do |key, value|
-          @attributes[key] = value
+          set_attribute(key, value)
         end
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.for"))
+        raise SyntaxError.new(options[:locale].t("errors.syntax.for".freeze))
       end
     end
 
     def strict_parse(markup)
       p = Parser.new(markup)
       @variable_name = p.consume(:id)
-      raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_in"))  unless p.id?('in')
-      @collection_name = p.expression
-      @name = "#{@variable_name}-#{@collection_name}"
-      @reversed = p.id?('reversed')
+      raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_in".freeze))  unless p.id?('in'.freeze)
+      collection_name = p.expression
+      @name = "#{@variable_name}-#{collection_name}"
+      @collection_name = Expression.parse(collection_name)
+      @reversed = p.id?('reversed'.freeze)
 
-      @attributes = {}
       while p.look(:id) && p.look(:colon, 1)
-        unless attribute = p.id?('limit') || p.id?('offset')
-          raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_attribute"))
+        unless attribute = p.id?('limit'.freeze) || p.id?('offset'.freeze)
+          raise SyntaxError.new(options[:locale].t("errors.syntax.for_invalid_attribute".freeze))
         end
         p.consume
-        val = p.expression
-        @attributes[attribute] = val
+        set_attribute(attribute, p.expression)
       end
       p.consume(:end_of_string)
     end
 
     private
 
-      def render_else(context)
-        return @else_block ? [render_all(@else_block, context)] : ''
+    def set_attribute(key, expr)
+      case key
+      when 'offset'.freeze
+        @from = if expr == 'continue'.freeze
+          :continue
+        else
+          Expression.parse(expr)
+        end
+      when 'limit'.freeze
+        @limit = Expression.parse(expr)
       end
+    end
 
-      def iterable?(collection)
-        collection.respond_to?(:each) || Utils.non_blank_string?(collection)
-      end
+    def render_else(context)
+      @else_block ? @else_block.render(context) : ''.freeze
+    end
   end
 
-  Template.register_tag('for', For)
+  Template.register_tag('for'.freeze, For)
 end

lib/liquid/tags/if.rb

@@ -14,18 +14,23 @@ module Liquid
     ExpressionsAndOperators = /(?:\b(?:\s?and\s?|\s?or\s?)\b|(?:\s*(?!\b(?:\s?and\s?|\s?or\s?)\b)(?:#{QuotedFragment}|\S+)\s*)+)/o
     BOOLEAN_OPERATORS = %w(and or)
 
-    def initialize(tag_name, markup, tokens)
-      @blocks = []
-      push_block('if', markup)
+    def initialize(tag_name, markup, options)
       super
+      @blocks = []
+      push_block('if'.freeze, markup)
+    end
+
+    def parse(tokens)
+      while parse_body(@blocks.last.attachment, tokens)
+      end
     end
 
     def nodelist
-      @blocks.map(&:attachment).flatten
+      @blocks.map(&:attachment)
     end
 
     def unknown_tag(tag, markup, tokens)
-      if ['elsif', 'else'].include?(tag)
+      if ['elsif'.freeze, 'else'.freeze].include?(tag)
         push_block(tag, markup)
       else
         super
@@ -36,71 +41,71 @@ module Liquid
       context.stack do
         @blocks.each do |block|
           if block.evaluate(context)
-            return render_all(block.attachment, context)
+            return block.attachment.render(context)
           end
         end
-        ''
+        ''.freeze
       end
     end
 
     private
 
-      def push_block(tag, markup)
-        block = if tag == 'else'
-          ElseCondition.new
-        else
-          parse_with_selected_parser(markup)
-        end
-
-        @blocks.push(block)
-        @nodelist = block.attach(Array.new)
+    def push_block(tag, markup)
+      block = if tag == 'else'.freeze
+        ElseCondition.new
+      else
+        parse_with_selected_parser(markup)
       end
 
-      def lax_parse(markup)
-        expressions = markup.scan(ExpressionsAndOperators).reverse
-        raise(SyntaxError.new(options[:locale].t("errors.syntax.if"))) unless expressions.shift =~ Syntax
+      @blocks.push(block)
+      block.attach(BlockBody.new)
+    end
 
-        condition = Condition.new($1, $2, $3)
+    def lax_parse(markup)
+      expressions = markup.scan(ExpressionsAndOperators)
+      raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless expressions.pop =~ Syntax
 
-        while not expressions.empty?
-          operator = (expressions.shift).to_s.strip
+      condition = Condition.new(Expression.parse($1), $2, Expression.parse($3))
 
-          raise(SyntaxError.new(options[:locale].t("errors.syntax.if"))) unless expressions.shift.to_s =~ Syntax
+      until expressions.empty?
+        operator = expressions.pop.to_s.strip
 
-          new_condition = Condition.new($1, $2, $3)
-          raise(SyntaxError.new(options[:locale].t("errors.syntax.if"))) unless BOOLEAN_OPERATORS.include?(operator)
-          new_condition.send(operator, condition)
-          condition = new_condition
-        end
+        raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless expressions.pop.to_s =~ Syntax
 
-        condition
+        new_condition = Condition.new(Expression.parse($1), $2, Expression.parse($3))
+        raise(SyntaxError.new(options[:locale].t("errors.syntax.if".freeze))) unless BOOLEAN_OPERATORS.include?(operator)
+        new_condition.send(operator, condition)
+        condition = new_condition
       end
 
-      def strict_parse(markup)
-        p = Parser.new(markup)
+      condition
+    end
 
-        condition = parse_comparison(p)
+    def strict_parse(markup)
+      p = Parser.new(markup)
+      condition = parse_binary_comparison(p)
+      p.consume(:end_of_string)
+      condition
+    end
 
-        while op = (p.id?('and') || p.id?('or'))
-          new_cond = parse_comparison(p)
-          new_cond.send(op, condition)
-          condition = new_cond
-        end
-        p.consume(:end_of_string)
-
-        condition
+    def parse_binary_comparison(p)
+      condition = parse_comparison(p)
+      if op = (p.id?('and'.freeze) || p.id?('or'.freeze))
+        condition.send(op, parse_binary_comparison(p))
       end
+      condition
+    end
 
-      def parse_comparison(p)
-        a = p.expression
-        if op = p.consume?(:comparison)
-          b = p.expression
-          Condition.new(a, op, b)
-        else
-          Condition.new(a)
-        end
+    def parse_comparison(p)
+      a = Expression.parse(p.expression)
+      if op = p.consume?(:comparison)
+        b = Expression.parse(p.expression)
+        Condition.new(a, op, b)
+      else
+        Condition.new(a)
       end
+    end
   end
 
-  Template.register_tag('if', If)
+  Template.register_tag('if'.freeze, If)
 end

lib/liquid/tags/ifchanged.rb

@@ -1,20 +1,18 @@
 module Liquid
   class Ifchanged < Block
-
     def render(context)
       context.stack do
-
         output = super
 
         if output != context.registers[:ifchanged]
           context.registers[:ifchanged] = output
           output
         else
-          ''
+          ''.freeze
         end
       end
     end
   end
 
-  Template.register_tag('ifchanged', Ifchanged)
+  Template.register_tag('ifchanged'.freeze, Ifchanged)
 end

lib/liquid/tags/include.rb

@@ -1,5 +1,4 @@
 module Liquid
-
   # Include allows templates to relate with other templates
   #
   # Simply include another template:
@@ -17,79 +16,96 @@ module Liquid
   class Include < Tag
     Syntax = /(#{QuotedFragment}+)(\s+(?:with|for)\s+(#{QuotedFragment}+))?/o
 
-    def initialize(tag_name, markup, tokens)
+    def initialize(tag_name, markup, options)
+      super
+
       if markup =~ Syntax
 
-        @template_name = $1
-        @variable_name = $3
-        @attributes    = {}
+        template_name = $1
+        variable_name = $3
+
+        @variable_name_expr = variable_name ? Expression.parse(variable_name) : nil
+        @template_name_expr = Expression.parse(template_name)
+        @attributes = {}
 
         markup.scan(TagAttributes) do |key, value|
-          @attributes[key] = value
+          @attributes[key] = Expression.parse(value)
         end
 
       else
-        raise SyntaxError.new(options[:locale].t("errors.syntax.include"))
+        raise SyntaxError.new(options[:locale].t("errors.syntax.include".freeze))
       end
-
-      super
     end
 
-    def blank?
-      false
+    def parse(_tokens)
     end
 
     def render(context)
-      partial = load_cached_partial(context)
-      variable = context[@variable_name || @template_name[1..-2]]
+      template_name = context.evaluate(@template_name_expr)
+      partial = load_cached_partial(template_name, context)
 
-      context.stack do
-        @attributes.each do |key, value|
-          context[key] = context[value]
-        end
+      context_variable_name = template_name.split('/'.freeze).last
 
-        context_variable_name = @template_name[1..-2].split('/').last
-        if variable.is_a?(Array)
-          variable.collect do |var|
-            context[context_variable_name] = var
+      variable = if @variable_name_expr
+        context.evaluate(@variable_name_expr)
+      else
+        context.find_variable(template_name)
+      end
+
+      old_template_name = context.template_name
+      begin
+        context.template_name = template_name
+        context.stack do
+          @attributes.each do |key, value|
+            context[key] = context.evaluate(value)
+          end
+
+          if variable.is_a?(Array)
+            variable.collect do |var|
+              context[context_variable_name] = var
+              partial.render(context)
+            end
+          else
+            context[context_variable_name] = variable
             partial.render(context)
           end
-        else
-          context[context_variable_name] = variable
-          partial.render(context)
         end
+      ensure
+        context.template_name = old_template_name
       end
     end
 
     private
-      def load_cached_partial(context)
-        cached_partials = context.registers[:cached_partials] || {}
-        template_name = context[@template_name]
 
-        if cached = cached_partials[template_name]
-          return cached
-        end
-        source = read_template_from_file_system(context)
-        partial = Liquid::Template.parse(source)
-        cached_partials[template_name] = partial
-        context.registers[:cached_partials] = cached_partials
-        partial
+    def load_cached_partial(template_name, context)
+      cached_partials = context.registers[:cached_partials] || {}
+
+      if cached = cached_partials[template_name]
+        return cached
       end
+      source = read_template_from_file_system(context)
+      partial = Liquid::Template.parse(source, pass_options)
+      cached_partials[template_name] = partial
+      context.registers[:cached_partials] = cached_partials
+      partial
+    end
 
-      def read_template_from_file_system(context)
-        file_system = context.registers[:file_system] || Liquid::Template.file_system
+    def read_template_from_file_system(context)
+      file_system = context.registers[:file_system] || Liquid::Template.file_system
 
-        # make read_template_file call backwards-compatible.
-        case file_system.method(:read_template_file).arity
-        when 1
-          file_system.read_template_file(context[@template_name])
-        when 2
-          file_system.read_template_file(context[@template_name], context)
-        else
-          raise ArgumentError, "file_system.read_template_file expects two parameters: (template_name, context)"
-        end
+      file_system.read_template_file(context.evaluate(@template_name_expr))
+    end
+
+    def pass_options
+      dont_pass = @options[:include_options_blacklist]
+      return { locale: @options[:locale] } if dont_pass == true
+      opts = @options.merge(included: true, include_options_blacklist: false)
+      if dont_pass.is_a?(Array)
+        dont_pass.each { |o| opts.delete(o) }
       end
+      opts
+    end
   end
 
-  Template.register_tag('include', Include)
+  Template.register_tag('include'.freeze, Include)
 end

lib/liquid/tags/increment.rb

@@ -15,9 +15,9 @@ module Liquid
   #    Hello: 2
   #
   class Increment < Tag
-    def initialize(tag_name, markup, tokens)
-      @variable = markup.strip
+    def initialize(tag_name, markup, options)
       super
+      @variable = markup.strip
     end
 
     def render(context)
@@ -25,11 +25,7 @@ module Liquid
       context.environments.first[@variable] = value + 1
       value.to_s
     end
-
-    def blank?
-      false
-    end
   end
 
-  Template.register_tag('increment', Increment)
+  Template.register_tag('increment'.freeze, Increment)
 end

lib/liquid/tags/raw.rb

@@ -1,19 +1,41 @@
 module Liquid
   class Raw < Block
-    FullTokenPossiblyInvalid = /\A(.*)#{TagStart}\s*(\w+)\s*(.*)?#{TagEnd}\z/o
+    Syntax = /\A\s*\z/
+    FullTokenPossiblyInvalid = /\A(.*)#{TagStart}\s*(\w+)\s*(.*)?#{TagEnd}\z/om
 
-    def parse_body(tokens)
-      @nodelist ||= []
-      @nodelist.clear
+    def initialize(tag_name, markup, options)
+      super
+
+      unless markup =~ Syntax
+        raise SyntaxError.new(@options[:locale].t("errors.syntax.tag_unexpected_args".freeze, tag: tag_name))
+      end
+    end
+
+    def parse(tokens)
+      @body = ''
       while token = tokens.shift
         if token =~ FullTokenPossiblyInvalid
-          @nodelist << $1 if $1 != ""
+          @body << $1 if $1 != "".freeze
           return if block_delimiter == $2
         end
-        @nodelist << token if not token.empty?
+        @body << token unless token.empty?
       end
+
+      raise SyntaxError.new(@options[:locale].t("errors.syntax.tag_never_closed".freeze, block_name: block_name))
+    end
+
+    def render(_context)
+      @body
+    end
+
+    def nodelist
+      [@body]
+    end
+
+    def blank?
+      @body.empty?
     end
   end
 
-  Template.register_tag('raw', Raw)
+  Template.register_tag('raw'.freeze, Raw)
 end

lib/liquid/tags/spaceless.rb

@@ -0,0 +1,24 @@
+module Liquid
+  # The spaceless tag strips whitespace between HTML tags using a simple regex.
+  #
+  # == Usage:
+  #    {% spaceless %}
+  #      <h1>
+  #        Hello
+  #      </h1>
+  #    {% endspaceless %}
+  #
+  class Spaceless < Block
+    HTML_STRIP_SPACE_REGEXP = />\s+</
+
+    def render(context)
+      self.class.strip_html_whitespace(super)
+    end
+
+    def self.strip_html_whitespace(input)
+      input.gsub(HTML_STRIP_SPACE_REGEXP, '><')
+    end
+  end
+
+  Template.register_tag('spaceless'.freeze, Spaceless)
+end

lib/liquid/tags/table_row.rb

@@ -0,0 +1,69 @@
+module Liquid
+  class TableRow < Block
+    Syntax = /(\w+)\s+in\s+(#{QuotedFragment}+)/o
+
+    def initialize(tag_name, markup, options)
+      super
+      if markup =~ Syntax
+        @variable_name = $1
+        @collection_name = Expression.parse($2)
+        @attributes = {}
+        markup.scan(TagAttributes) do |key, value|
+          @attributes[key] = Expression.parse(value)
+        end
+      else
+        raise SyntaxError.new(options[:locale].t("errors.syntax.table_row".freeze))
+      end
+    end
+
+    def render(context)
+      collection = context.evaluate(@collection_name) or return ''.freeze
+
+      from = @attributes.key?('offset'.freeze) ? context.evaluate(@attributes['offset'.freeze]).to_i : 0
+      to = @attributes.key?('limit'.freeze) ? from + context.evaluate(@attributes['limit'.freeze]).to_i : nil
+
+      collection = Utils.slice_collection(collection, from, to)
+
+      length = collection.length
+
+      cols = context.evaluate(@attributes['cols'.freeze]).to_i
+
+      row = 1
+      col = 0
+
+      result = "<tr class=\"row1\">\n"
+      context.stack do
+        collection.each_with_index do |item, index|
+          context[@variable_name] = item
+          context['tablerowloop'.freeze] = {
+            'length'.freeze    => length,
+            'index'.freeze     => index + 1,
+            'index0'.freeze    => index,
+            'col'.freeze       => col + 1,
+            'col0'.freeze      => col,
+            'rindex'.freeze    => length - index,
+            'rindex0'.freeze   => length - index - 1,
+            'first'.freeze     => (index == 0),
+            'last'.freeze      => (index == length - 1),
+            'col_first'.freeze => (col == 0),
+            'col_last'.freeze  => (col == cols - 1)
+          }
+
+          col += 1
+
+          result << "<td class=\"col#{col}\">" << super << '</td>'
+
+          if col == cols && (index != length - 1)
+            col  = 0
+            row += 1
+            result << "</tr>\n<tr class=\"row#{row}\">"
+          end
+        end
+      end
+      result << "</tr>\n"
+      result
+    end
+  end
+
+  Template.register_tag('tablerow'.freeze, TableRow)
+end

lib/liquid/tags/unless.rb

@@ -1,33 +1,30 @@
-require File.dirname(__FILE__) + '/if'
+require_relative 'if'
 
 module Liquid
-
   # Unless is a conditional just like 'if' but works on the inverse logic.
   #
-  #   {% unless x < 0 %} x is greater than zero {% end %}
+  #   {% unless x < 0 %} x is greater than zero {% endunless %}
   #
   class Unless < If
     def render(context)
       context.stack do
-
         # First condition is interpreted backwards ( if not )
         first_block = @blocks.first
         unless first_block.evaluate(context)
-          return render_all(first_block.attachment, context)
+          return first_block.attachment.render(context)
         end
 
         # After the first condition unless works just like if
         @blocks[1..-1].each do |block|
           if block.evaluate(context)
-            return render_all(block.attachment, context)
+            return block.attachment.render(context)
           end
         end
 
-        ''
+        ''.freeze
       end
     end
   end
 
-
-  Template.register_tag('unless', Unless)
+  Template.register_tag('unless'.freeze, Unless)
 end

lib/liquid/template.rb

@@ -1,5 +1,4 @@
 module Liquid
-
   # Templates are central to liquid.
   # Interpretating templates is a two step process. First you compile the
   # source code you got. During compile time some extensive error checking is performed.
@@ -14,14 +13,56 @@ module Liquid
   #   template.render('user_name' => 'bob')
   #
   class Template
-    DEFAULT_OPTIONS = {
-      :locale => I18n.new
-    }
+    attr_accessor :root
+    attr_reader :resource_limits
 
-    attr_accessor :root, :resource_limits
     @@file_system = BlankFileSystem.new
 
+    class TagRegistry
+      def initialize
+        @tags  = {}
+        @cache = {}
+      end
+
+      def [](tag_name)
+        return nil unless @tags.key?(tag_name)
+        return @cache[tag_name] if Liquid.cache_classes
+
+        lookup_class(@tags[tag_name]).tap { |o| @cache[tag_name] = o }
+      end
+
+      def []=(tag_name, klass)
+        @tags[tag_name]  = klass.name
+        @cache[tag_name] = klass
+      end
+
+      def delete(tag_name)
+        @tags.delete(tag_name)
+        @cache.delete(tag_name)
+      end
+
+      private
+
+      def lookup_class(name)
+        name.split("::").reject(&:empty?).reduce(Object) { |scope, const| scope.const_get(const) }
+      end
+    end
+
+    attr_reader :profiler
+
     class << self
+      # Sets how strict the parser should be.
+      # :lax acts like liquid 2.5 and silently ignores malformed tags in most cases.
+      # :warn is the default and will give deprecation warnings when invalid syntax is used.
+      # :strict will enforce correct syntax.
+      attr_writer :error_mode
+
+      # Sets how strict the taint checker should be.
+      # :lax is the default, and ignores the taint flag completely
+      # :warn adds a warning, but does not interrupt the rendering
+      # :error raises an error when tainted output is used
+      attr_writer :taint_mode
+
       def file_system
         @@file_system
       end
@@ -35,44 +76,47 @@ module Liquid
       end
 
       def tags
-        @tags ||= {}
-      end
-
-      # Sets how strict the parser should be.
-      # :lax acts like liquid 2.5 and silently ignores malformed tags in most cases.
-      # :warn is the default and will give deprecation warnings when invalid syntax is used.
-      # :strict will enforce correct syntax.
-      def error_mode=(mode)
-        @error_mode = mode
+        @tags ||= TagRegistry.new
       end
 
       def error_mode
         @error_mode || :lax
       end
 
+      def taint_mode
+        @taint_mode || :lax
+      end
+
       # Pass a module with filter methods which should be available
       # to all liquid views. Good for registering the standard library
       def register_filter(mod)
         Strainer.global_filter(mod)
       end
 
+      def default_resource_limits
+        @default_resource_limits ||= {}
+      end
+
       # creates a new <tt>Template</tt> object from liquid source code
+      # To enable profiling, pass in <tt>profile: true</tt> as an option.
+      # See Liquid::Profiler for more information
       def parse(source, options = {})
         template = Template.new
         template.parse(source, options)
-        template
       end
     end
 
-    # creates a new <tt>Template</tt> from an array of tokens. Use <tt>Template.parse</tt> instead
     def initialize
-      @resource_limits = {}
+      @resource_limits = ResourceLimits.new(self.class.default_resource_limits)
     end
 
     # Parse source code.
     # Returns self for easy chaining
     def parse(source, options = {})
-      @root = Document.new(tokenize(source), DEFAULT_OPTIONS.merge(options))
+      @options = options
+      @profiling = options[:profile]
+      @line_numbers = options[:line_numbers] || @profiling
+      @root = Document.parse(tokenize(source), options)
       @warnings = nil
       self
     end
@@ -103,6 +147,9 @@ module Liquid
     # if you use the same filters over and over again consider registering them globally
     # with <tt>Template.register_filter</tt>
     #
+    # if profiling was enabled in <tt>Template#parse</tt> then the resulting profiling information
+    # will be available via <tt>Template#profiler</tt>
+    #
     # Following options can be passed:
     #
     #  * <tt>filters</tt> : array with local filters
@@ -110,11 +157,17 @@ module Liquid
     #    filters and tags and might be useful to integrate liquid more with its host application
     #
     def render(*args)
-      return '' if @root.nil?
+      return ''.freeze if @root.nil?
 
       context = case args.first
       when Liquid::Context
-        args.shift
+        c = args.shift
+
+        if @rethrow_errors
+          c.exception_handler = ->(e) { raise }
+        end
+
+        c
       when Liquid::Drop
         drop = args.shift
         drop.context = Context.new([drop, assigns], instance_assigns, registers, @rethrow_errors, @resource_limits)
@@ -131,23 +184,31 @@ module Liquid
         options = args.pop
 
         if options[:registers].is_a?(Hash)
-          self.registers.merge!(options[:registers])
+          registers.merge!(options[:registers])
         end
 
         if options[:filters]
           context.add_filters(options[:filters])
         end
 
+        if options[:exception_handler]
+          context.exception_handler = options[:exception_handler]
+        end
       when Module
         context.add_filters(args.pop)
       when Array
         context.add_filters(args.pop)
       end
 
+      # Retrying a render resets resource usage
+      context.resource_limits.reset
+
       begin
         # render the nodelist.
         # for performance reasons we get an array back here. join will make a string out of it.
-        result = @root.render(context)
+        result = with_profiling do
+          @root.render(context)
+        end
         result.respond_to?(:join) ? result.join : result
       rescue Liquid::MemoryError => e
         context.handle_error(e)
@@ -157,15 +218,31 @@ module Liquid
     end
 
     def render!(*args)
-      @rethrow_errors = true; render(*args)
+      @rethrow_errors = true
+      render(*args)
     end
 
     private
 
     def tokenize(source)
-      source = source.source if source.respond_to?(:source)
-      Tokenizer.new(source.to_s)
+      Tokenizer.new(source, @line_numbers)
     end
 
+    def with_profiling
+      if @profiling && !@options[:included]
+        raise "Profiler not loaded, require 'liquid/profiler' first" unless defined?(Liquid::Profiler)
+
+        @profiler = Profiler.new
+        @profiler.start
+
+        begin
+          yield
+        ensure
+          @profiler.stop
+        end
+      else
+        yield
+      end
+    end
   end
 end

lib/liquid/token.rb

@@ -0,0 +1,18 @@
+module Liquid
+  class Token < String
+    attr_reader :line_number
+
+    def initialize(content, line_number)
+      super(content)
+      @line_number = line_number
+    end
+
+    def raw
+      "<raw>"
+    end
+
+    def child(string)
+      Token.new(string, @line_number)
+    end
+  end
+end

lib/liquid/tokenizer.rb

@@ -0,0 +1,37 @@
+module Liquid
+  class Tokenizer
+    def initialize(source, line_numbers = false)
+      @source = source
+      @line_numbers = line_numbers
+      @tokens = tokenize
+    end
+
+    def shift
+      @tokens.shift
+    end
+
+    private
+
+    def tokenize
+      @source = @source.source if @source.respond_to?(:source)
+      return [] if @source.to_s.empty?
+
+      tokens = @source.split(TemplateParser)
+      tokens = @line_numbers ? calculate_line_numbers(tokens) : tokens
+
+      # removes the rogue empty element at the beginning of the array
+      tokens.shift if tokens[0] && tokens[0].empty?
+
+      tokens
+    end
+
+    def calculate_line_numbers(tokens)
+      current_line = 1
+      tokens.map do |token|
+        Token.new(token, current_line).tap do
+          current_line += token.count("\n")
+        end
+      end
+    end
+  end
+end

lib/liquid/utils.rb

@@ -1,27 +1,24 @@
 module Liquid
   module Utils
-
     def self.slice_collection(collection, from, to)
-      if (from != 0 || to != nil) && collection.respond_to?(:load_slice)
+      if (from != 0 || !to.nil?) && collection.respond_to?(:load_slice)
         collection.load_slice(from, to)
       else
         slice_collection_using_each(collection, from, to)
       end
     end
 
-    def self.non_blank_string?(collection)
-      collection.is_a?(String) && collection != ''
-    end
-
     def self.slice_collection_using_each(collection, from, to)
       segments = []
       index = 0
 
       # Maintains Ruby 1.8.7 String#each behaviour on 1.9
-      return [collection] if non_blank_string?(collection)
+      if collection.is_a?(String)
+        return collection.empty? ? [] : [collection]
+      end
+      return [] unless collection.respond_to?(:each)
 
       collection.each do |item|
-
         if to && to <= index
           break
         end

lib/liquid/variable.rb

@@ -1,5 +1,4 @@
 module Liquid
-
   # Holds variables. Variables are only loaded "just in time"
   # and are not evaluated as part of the render stage
   #
@@ -11,96 +10,112 @@ module Liquid
   #   {{ user | link }}
   #
   class Variable
-    EasyParse = /\A *(\w+(?:\.\w+)*) *\z/
+    FilterParser = /(?:\s+|#{QuotedFragment}|#{ArgumentSeparator})+/o
     attr_accessor :filters, :name, :warnings
+    attr_accessor :line_number
+    include ParserSwitching
 
     def initialize(markup, options = {})
       @markup  = markup
       @name    = nil
       @options = options || {}
-      
 
-      case @options[:error_mode] || Template.error_mode
-      when :strict then strict_parse(markup)
-      when :lax    then lax_parse(markup)
-      when :warn
-        begin
-          strict_parse(markup)
-        rescue SyntaxError => e
-          @warnings ||= []
-          @warnings << e
-          lax_parse(markup)
+      parse_with_selected_parser(markup)
+    end
+
+    def raw
+      @markup
+    end
+
+    def markup_context(markup)
+      "in \"{{#{markup}}}\""
+    end
+
+    def lax_parse(markup)
+      @filters = []
+      return unless markup =~ /(#{QuotedFragment})(.*)/om
+
+      name_markup = $1
+      filter_markup = $2
+      @name = Expression.parse(name_markup)
+      if filter_markup =~ /#{FilterSeparator}\s*(.*)/om
+        filters = $1.scan(FilterParser)
+        filters.each do |f|
+          next unless f =~ /\w+/
+          filtername = Regexp.last_match(0)
+          filterargs = f.scan(/(?:#{FilterArgumentSeparator}|#{ArgumentSeparator})\s*((?:\w+\s*\:\s*)?#{QuotedFragment})/o).flatten
+          @filters << parse_filter_expressions(filtername, filterargs)
         end
       end
     end
 
-#     def lax_parse(markup)
-#       @filters = []
-#       if match = markup.match(/\s*(#{QuotedFragment})(.*)/o)
-#         @name = match[1]
-#         if match[2].match(/#{FilterSeparator}\s*(.*)/o)
-#           filters = Regexp.last_match(1).scan(FilterParser)
-#           filters.each do |f|
-#             if matches = f.match(/\s*(\w+)/)
-#               filtername = matches[1]
-#               filterargs = f.scan(/(?:#{FilterArgumentSeparator}|#{ArgumentSeparator})\s*((?:\w+\s*\:\s*)?#{QuotedFragment})/o).flatten
-#               @filters << [filtername, filterargs]
-#             end
-#           end
-#         end
-#       end
-#     end
-
     def strict_parse(markup)
-      # Very simple valid cases
-      if markup =~ EasyParse
-        @name = $1
-        @filters = []
-        return
-      end
-
       @filters = []
       p = Parser.new(markup)
-      # Could be just filters with no input
-      @name = p.look(:pipe) ? '' : p.expression
+
+      @name = Expression.parse(p.expression)
       while p.consume?(:pipe)
         filtername = p.consume(:id)
         filterargs = p.consume?(:colon) ? parse_filterargs(p) : []
-        @filters << [filtername, filterargs]
+        @filters << parse_filter_expressions(filtername, filterargs)
       end
       p.consume(:end_of_string)
-    rescue SyntaxError => e
-      e.message << " in \"{{#{markup}}}\""
-      raise e
     end
 
     def parse_filterargs(p)
       # first argument
       filterargs = [p.argument]
       # followed by comma separated others
-      while p.consume?(:comma)
-        filterargs << p.argument
-      end
+      filterargs << p.argument while p.consume?(:comma)
       filterargs
     end
 
     def render(context)
-      return '' if @name.nil?
-      @filters.inject(context[@name]) do |output, filter|
-        filterargs = []
-        keyword_args = {}
-        filter[1].to_a.each do |a|
-          if matches = a.match(/\A#{TagAttributes}\z/o)
-            keyword_args[matches[1]] = context[matches[2]]
-          else
-            filterargs << context[a]
-          end
+      @filters.inject(context.evaluate(@name)) do |output, (filter_name, filter_args, filter_kwargs)|
+        filter_args = evaluate_filter_expressions(context, filter_args, filter_kwargs)
+        context.invoke(filter_name, output, *filter_args)
+      end.tap{ |obj| taint_check(obj) }
+    end
+
+    private
+
+    def parse_filter_expressions(filter_name, unparsed_args)
+      filter_args = []
+      keyword_args = {}
+      unparsed_args.each do |a|
+        if matches = a.match(/\A#{TagAttributes}\z/o)
+          keyword_args[matches[1]] = Expression.parse(matches[2])
+        else
+          filter_args << Expression.parse(a)
         end
-        filterargs << keyword_args unless keyword_args.empty?
-        begin
-          output = context.invoke(filter[0], output, *filterargs)
-        rescue FilterNotFound
-          raise FilterNotFound, "Error - filter '#{filter[0]}' in '#{@markup.strip}' could not be found."
+      end
+      result = [filter_name, filter_args]
+      result << keyword_args unless keyword_args.empty?
+      result
+    end
+
+    def evaluate_filter_expressions(context, filter_args, filter_kwargs)
+      parsed_args = filter_args.map{ |expr| context.evaluate(expr) }
+      if filter_kwargs
+        parsed_kwargs = {}
+        filter_kwargs.each do |key, expr|
+          parsed_kwargs[key] = context.evaluate(expr)
+        end
+        parsed_args << parsed_kwargs
+      end
+      parsed_args
+    end
+
+    def taint_check(obj)
+      if obj.tainted?
+        @markup =~ QuotedFragment
+        name = Regexp.last_match(0)
+        case Template.taint_mode
+        when :warn
+          @warnings ||= []
+          @warnings << "variable '#{name}' is tainted and was not escaped"
+        when :error
+          raise TaintedError, "Error - variable '#{name}' is tainted and was not escaped"
         end
       end
     end

lib/liquid/variable_lookup.rb

@@ -0,0 +1,80 @@
+module Liquid
+  class VariableLookup
+    SQUARE_BRACKETED = /\A\[(.*)\]\z/m
+    COMMAND_METHODS = ['size'.freeze, 'first'.freeze, 'last'.freeze]
+
+    attr_reader :name, :lookups
+
+    def self.parse(markup)
+      new(markup)
+    end
+
+    def initialize(markup)
+      lookups = markup.scan(VariableParser)
+
+      name = lookups.shift
+      if name =~ SQUARE_BRACKETED
+        name = Expression.parse($1)
+      end
+      @name = name
+
+      @lookups = lookups
+      @command_flags = 0
+
+      @lookups.each_index do |i|
+        lookup = lookups[i]
+        if lookup =~ SQUARE_BRACKETED
+          lookups[i] = Expression.parse($1)
+        elsif COMMAND_METHODS.include?(lookup)
+          @command_flags |= 1 << i
+        end
+      end
+    end
+
+    def evaluate(context)
+      name = context.evaluate(@name)
+      object = context.find_variable(name)
+
+      @lookups.each_index do |i|
+        key = context.evaluate(@lookups[i])
+
+        # If object is a hash- or array-like object we look for the
+        # presence of the key and if its available we return it
+        if object.respond_to?(:[]) &&
+            ((object.respond_to?(:key?) && object.key?(key)) ||
+             (object.respond_to?(:fetch) && key.is_a?(Integer)))
+
+          # if its a proc we will replace the entry with the proc
+          res = context.lookup_and_evaluate(object, key)
+          object = res.to_liquid
+
+          # Some special cases. If the part wasn't in square brackets and
+          # no key with the same name was found we interpret following calls
+          # as commands and call them on the current object
+        elsif @command_flags & (1 << i) != 0 && object.respond_to?(key)
+          object = object.send(key).to_liquid
+
+          # No key was present with the desired value and it wasn't one of the directly supported
+          # keywords either. The only thing we got left is to return nil
+        else
+          return nil
+        end
+
+        # If we are dealing with a drop here we have to
+        object.context = context if object.respond_to?(:context=)
+      end
+
+      object
+    end
+
+    def ==(other)
+      self.class == other.class && state == other.state
+    end
+
+    protected
+
+    def state
+      [@name, @lookups, @command_flags]
+    end
+  end
+end

lib/liquid/version.rb

@@ -1,4 +1,4 @@
 # encoding: utf-8
 module Liquid
-  VERSION = "3.0.0"
+  VERSION = "4.0.0.alpha"
 end

liquid.gemspec

@@ -1,6 +1,6 @@
 # encoding: utf-8
 lib = File.expand_path('../lib/', __FILE__)
-$:.unshift lib unless $:.include?(lib)
+$LOAD_PATH.unshift lib unless $LOAD_PATH.include?(lib)
 
 require "liquid/version"
 
@@ -9,24 +9,21 @@ Gem::Specification.new do |s|
   s.version     = Liquid::VERSION
   s.platform    = Gem::Platform::RUBY
   s.summary     = "A secure, non-evaling end user template engine with aesthetic markup."
-  s.authors     = ["Tobias Luetke"]
+  s.authors     = ["Tobias Lütke"]
   s.email       = ["tobi@leetsoft.com"]
   s.homepage    = "http://www.liquidmarkup.org"
   s.license     = "MIT"
-  #s.description = "A secure, non-evaling end user template engine with aesthetic markup."
+  # s.description = "A secure, non-evaling end user template engine with aesthetic markup."
 
   s.required_rubygems_version = ">= 1.3.7"
 
   s.test_files  = Dir.glob("{test}/**/*")
-  s.files       = Dir.glob("{lib,ext}/**/*") + %w(MIT-LICENSE README.md)
-  s.extensions  = ['ext/liquid/extconf.rb']
+  s.files       = Dir.glob("{lib}/**/*") + %w(MIT-LICENSE README.md)
 
   s.extra_rdoc_files  = ["History.md", "README.md"]
 
   s.require_path = "lib"
 
-  s.add_development_dependency 'rake-compiler'
-  s.add_development_dependency 'stackprof'
   s.add_development_dependency 'rake'
-  s.add_development_dependency 'activesupport'
+  s.add_development_dependency 'minitest'
 end

performance/benchmark.rb

@@ -1,12 +1,17 @@
-require 'rubygems'
-require 'benchmark'
-require File.dirname(__FILE__) + '/theme_runner'
+require 'benchmark/ips'
+require_relative 'theme_runner'
 
 Liquid::Template.error_mode = ARGV.first.to_sym if ARGV.first
 profiler = ThemeRunner.new
 
-Benchmark.bmbm do |x|
-  x.report("parse:")   { 100.times { profiler.compile } }
-  x.report("parse & run:")   { 100.times { profiler.run } }
-end
+Benchmark.ips do |x|
+  x.time = 60
+  x.warmup = 5
 
+  puts
+  puts "Running benchmark for #{x.time} seconds (with #{x.warmup} seconds warmup)."
+  puts
+
+  x.report("parse:") { profiler.compile }
+  x.report("parse & run:") { profiler.run }
+end

performance/profile.rb

@@ -1,19 +1,24 @@
-require 'rubygems'
-require 'ruby-prof' rescue fail("install ruby-prof extension/gem")
-require File.dirname(__FILE__) + '/theme_runner'
+require 'stackprof'
+require_relative 'theme_runner'
 
+Liquid::Template.error_mode = ARGV.first.to_sym if ARGV.first
 profiler = ThemeRunner.new
+profiler.run
 
-puts 'Running profiler...'
+[:cpu, :object].each do |profile_type|
+  puts "Profiling in #{profile_type} mode..."
+  results = StackProf.run(mode: profile_type) do
+    200.times do
+      profiler.run
+    end
+  end
 
-results  = profiler.run_profile
+  if profile_type == :cpu && graph_filename = ENV['GRAPH_FILENAME']
+    File.open(graph_filename, 'w') do |f|
+      StackProf::Report.new(results).print_graphviz(nil, f)
+    end
+  end
 
-puts 'Success'
-puts
-
-[RubyProf::FlatPrinter, RubyProf::GraphHtmlPrinter, RubyProf::CallTreePrinter, RubyProf::DotPrinter].each do |klass|
-  filename = (ENV['TMP'] || '/tmp') + (klass.name.include?('Html') ? "/liquid.#{klass.name.downcase}.html" : "/callgrind.liquid.#{klass.name.downcase}.txt")
-  filename.gsub!(/:+/, '_')
-  File.open(filename, "w+") { |fp| klass.new(results).print(fp, :print_file => true, :min_percent => 3) }
-  $stderr.puts "wrote #{klass.name} output to #{filename}"
+  StackProf::Report.new(results).print_text(false, 20)
+  File.write(ENV['FILENAME'] + "." + profile_type.to_s, Marshal.dump(results)) if ENV['FILENAME']
 end

performance/shopify/comment_form.rb

@@ -1,15 +1,15 @@
 class CommentForm < Liquid::Block
   Syntax = /(#{Liquid::VariableSignature}+)/
 
-  def initialize(tag_name, markup, tokens)
+  def initialize(tag_name, markup, options)
+    super
+
     if markup =~ Syntax
       @variable_name = $1
       @attributes = {}
     else
       raise SyntaxError.new("Syntax Error in 'comment_form' - Valid syntax: comment_form [article]")
     end
-
-    super
   end
 
   def render(context)
@@ -28,6 +28,6 @@ class CommentForm < Liquid::Block
   end
 
   def wrap_in_form(article, input)
-    %Q{<form id="article-#{article.id}-comment-form" class="comment-form" method="post" action="">\n#{input}\n</form>}
+    %(<form id="article-#{article.id}-comment-form" class="comment-form" method="post" action="">\n#{input}\n</form>)
   end
 end

performance/shopify/database.rb

@@ -1,11 +1,11 @@
 require 'yaml'
-module Database
 
+module Database
   # Load the standard vision toolkit database and re-arrage it to be simply exportable
   # to liquid as assigns. All this is based on Shopify
   def self.tables
     @tables ||= begin
-      db = YAML.load_file(File.dirname(__FILE__) + '/vision.database.yml')
+      db = YAML.load_file("#{__dir__}/vision.database.yml")
 
       # From vision source
       db['products'].each do |product|
@@ -39,7 +39,7 @@ module Database
   end
 end
 
-if __FILE__ == $0
+if __FILE__ == $PROGRAM_NAME
   p Database.tables['collections']['frontpage'].keys
-  #p Database.tables['blog']['articles']
+  # p Database.tables['blog']['articles']
 end

performance/shopify/json_filter.rb

@@ -1,7 +1,7 @@
+require 'json'
+
 module JsonFilter
-
   def json(object)
-    object.reject {|k,v| k == "collections" }.to_json
+    JSON.dump(object.reject { |k, v| k == "collections" })
   end
-
 end

performance/shopify/liquid.rb

@@ -1,13 +1,13 @@
-$:.unshift File.dirname(__FILE__) + '/../../lib'
-require File.dirname(__FILE__) + '/../../lib/liquid'
+$:.unshift __dir__ + '/../../lib'
+require_relative '../../lib/liquid'
 
-require File.dirname(__FILE__) + '/comment_form'
-require File.dirname(__FILE__) + '/paginate'
-require File.dirname(__FILE__) + '/json_filter'
-require File.dirname(__FILE__) + '/money_filter'
-require File.dirname(__FILE__) + '/shop_filter'
-require File.dirname(__FILE__) + '/tag_filter'
-require File.dirname(__FILE__) + '/weight_filter'
+require_relative 'comment_form'
+require_relative 'paginate'
+require_relative 'json_filter'
+require_relative 'money_filter'
+require_relative 'shop_filter'
+require_relative 'tag_filter'
+require_relative 'weight_filter'
 
 Liquid::Template.register_tag 'paginate', Paginate
 Liquid::Template.register_tag 'form', CommentForm

performance/shopify/money_filter.rb

@@ -1,13 +1,12 @@
 module MoneyFilter
-
   def money_with_currency(money)
     return '' if money.nil?
-    sprintf("$ %.2f USD", money/100.0)
+    sprintf("$ %.2f USD", money / 100.0)
   end
 
   def money(money)
     return '' if money.nil?
-    sprintf("$ %.2f", money/100.0)
+    sprintf("$ %.2f", money / 100.0)
   end
 
   private

performance/shopify/paginate.rb

@@ -1,8 +1,8 @@
 class Paginate < Liquid::Block
   Syntax     = /(#{Liquid::QuotedFragment})\s*(by\s*(\d+))?/
 
-  def initialize(tag_name, markup, tokens)
-    @nodelist = []
+  def initialize(tag_name, markup, options)
+    super
 
     if markup =~ Syntax
       @collection_name = $1
@@ -19,8 +19,6 @@ class Paginate < Liquid::Block
     else
       raise SyntaxError.new("Syntax Error in tag 'paginate' - Valid syntax: paginate [collection] by number")
     end
-
-    super
   end
 
   def render(context)
@@ -44,23 +42,22 @@ class Paginate < Liquid::Block
       page_count = (collection_size.to_f / @page_size.to_f).to_f.ceil + 1
 
       pagination['items']      = collection_size
-      pagination['pages']      = page_count -1
-      pagination['previous']   = link('&laquo; Previous', current_page-1 )  unless 1 >= current_page
-      pagination['next']       = link('Next &raquo;', current_page+1 )      unless page_count <= current_page+1
+      pagination['pages']      = page_count - 1
+      pagination['previous']   = link('&laquo; Previous', current_page - 1)  unless 1 >= current_page
+      pagination['next']       = link('Next &raquo;', current_page + 1)      unless page_count <= current_page + 1
       pagination['parts']      = []
 
       hellip_break = false
 
       if page_count > 2
-        1.upto(page_count-1) do |page|
-
+        1.upto(page_count - 1) do |page|
           if current_page == page
             pagination['parts'] << no_link(page)
           elsif page == 1
             pagination['parts'] << link(page, page)
-          elsif page == page_count -1
+          elsif page == page_count - 1
             pagination['parts'] << link(page, page)
-          elsif page <= current_page - @attributes['window_size'] or page >= current_page + @attributes['window_size']
+          elsif page <= current_page - @attributes['window_size'] || page >= current_page + @attributes['window_size']
             next if hellip_break
             pagination['parts'] << no_link('&hellip;')
             hellip_break = true
@@ -73,18 +70,18 @@ class Paginate < Liquid::Block
         end
       end
 
-      render_all(@nodelist, context)
+      super
     end
   end
 
   private
 
   def no_link(title)
-    { 'title' => title, 'is_link' => false}
+    { 'title' => title, 'is_link' => false }
   end
 
   def link(title, page)
-    { 'title' => title, 'url' => current_url + "?page=#{page}", 'is_link' => true}
+    { 'title' => title, 'url' => current_url + "?page=#{page}", 'is_link' => true }
   end
 
   def current_url

performance/shopify/shop_filter.rb

@@ -1,5 +1,4 @@
 module ShopFilter
-
   def asset_url(input)
     "/files/1/[shop_id]/[shop_id]/assets/#{input}"
   end
@@ -16,16 +15,16 @@ module ShopFilter
     %(<script src="#{url}" type="text/javascript"></script>)
   end
 
-  def stylesheet_tag(url, media="all")
+  def stylesheet_tag(url, media = "all")
     %(<link href="#{url}" rel="stylesheet" type="text/css"  media="#{media}"  />)
   end
 
-  def link_to(link, url, title="")
-    %|<a href="#{url}" title="#{title}">#{link}</a>|
+  def link_to(link, url, title = "")
+    %(<a href="#{url}" title="#{title}">#{link}</a>)
   end
 
-  def img_tag(url, alt="")
-    %|<img src="#{url}" alt="#{alt}" />|
+  def img_tag(url, alt = "")
+    %(<img src="#{url}" alt="#{alt}" />)
   end
 
   def link_to_vendor(vendor)
@@ -45,15 +44,14 @@ module ShopFilter
   end
 
   def url_for_vendor(vendor_title)
-    "/collections/#{vendor_title.to_handle}"
+    "/collections/#{to_handle(vendor_title)}"
   end
 
   def url_for_type(type_title)
-    "/collections/#{type_title.to_handle}"
+    "/collections/#{to_handle(type_title)}"
   end
 
   def product_img_url(url, style = 'small')
-
     unless url =~ /\Aproducts\/([\w\-\_]+)\.(\w{2,4})/
       raise ArgumentError, 'filter "size" can only be called on product images'
     end
@@ -69,7 +67,6 @@ module ShopFilter
   end
 
   def default_pagination(paginate)
-
     html = []
     html << %(<span class="prev">#{link_to(paginate['previous']['title'], paginate['previous']['url'])}</span>) if paginate['previous']
 
@@ -95,4 +92,15 @@ module ShopFilter
     input == 1 ? singular : plural
   end
 
+  private
+
+  def to_handle(str)
+    result = str.dup
+    result.downcase!
+    result.delete!("'\"()[]")
+    result.gsub!(/\W+/, '-')
+    result.gsub!(/-+\z/, '') if result[-1] == '-'
+    result.gsub!(/\A-+/, '') if result[0] == '-'
+    result
+  end
 end

performance/shopify/tag_filter.rb

@@ -1,10 +1,9 @@
 module TagFilter
-
   def link_to_tag(label, tag)
     "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tag}\">#{label}</a>"
   end
 
-  def highlight_active_tag(tag, css_class='active')
+  def highlight_active_tag(tag, css_class = 'active')
     if @context['current_tags'].include?(tag)
       "<span class=\"#{css_class}\">#{tag}</span>"
     else
@@ -21,5 +20,4 @@ module TagFilter
     tags = (@context['current_tags'] - [tag]).uniq
     "<a title=\"Show tag #{tag}\" href=\"/collections/#{@context['handle']}/#{tags.join("+")}\">#{label}</a>"
   end
-
 end

performance/shopify/weight_filter.rb

@@ -1,5 +1,4 @@
 module WeightFilter
-
   def weight(grams)
     sprintf("%.2f", grams / 1000)
   end
@@ -7,5 +6,4 @@ module WeightFilter
   def weight_with_unit(grams)
     "#{weight(grams)} kg"
   end
-
 end

performance/stackprof.rb

@@ -1,15 +0,0 @@
-require 'stackprof' rescue fail("install stackprof extension/gem")
-require File.dirname(__FILE__) + '/theme_runner'
-
-profiler = ThemeRunner.new
-profiler.run
-results = StackProf.run(mode: :cpu, out: ENV['FILENAME']) do
-  100.times do
-    profiler.run
-  end
-end
-if results.kind_of?(File)
-  puts "wrote stackprof dump to #{results.path}"
-else
-  StackProf::Report.new(results).print_text(false, 20)
-end

performance/theme_runner.rb

@@ -6,22 +6,17 @@
 # Shopify which is likely the biggest user of liquid in the world which something to the tune of several
 # million Template#render calls a day.
 
-require 'rubygems'
-require 'active_support'
-require 'yaml'
-require 'digest/md5'
-require File.dirname(__FILE__) + '/shopify/liquid'
-require File.dirname(__FILE__) + '/shopify/database.rb'
+require_relative 'shopify/liquid'
+require_relative 'shopify/database'
 
 class ThemeRunner
   class FileSystem
-
     def initialize(path)
       @path = path
     end
 
     # Called by Liquid to retrieve a template file
-    def read_template_file(template_path, context)
+    def read_template_file(template_path)
       File.read(@path + '/' + template_path + '.liquid')
     end
   end
@@ -29,7 +24,7 @@ class ThemeRunner
   # Load all templates into memory, do this now so that
   # we don't profile IO.
   def initialize
-    @tests = Dir[File.dirname(__FILE__) + '/tests/**/*.liquid'].collect do |test|
+    @tests = Dir[__dir__ + '/tests/**/*.liquid'].collect do |test|
       next if File.basename(test) == 'theme.liquid'
 
       theme_path = File.dirname(test) + '/theme.liquid'
@@ -42,7 +37,6 @@ class ThemeRunner
     # Dup assigns because will make some changes to them
 
     @tests.each do |liquid, layout, template_name|
-
       tmpl = Liquid::Template.new
       tmpl.parse(liquid)
       tmpl = Liquid::Template.new
@@ -50,71 +44,30 @@ class ThemeRunner
     end
   end
 
-   def run
+  def run
     # Dup assigns because will make some changes to them
     assigns = Database.tables.dup
 
     @tests.each do |liquid, layout, template_name|
-
       # Compute page_tempalte outside of profiler run, uninteresting to profiler
       page_template = File.basename(template_name, File.extname(template_name))
       compile_and_render(liquid, layout, assigns, page_template, template_name)
-
     end
   end
 
-
-  def run_profile
-    RubyProf.measure_mode = RubyProf::WALL_TIME
-
-    # Dup assigns because will make some changes to them
-    assigns = Database.tables.dup
-
-    @tests.each do |liquid, layout, template_name|
-
-      # Compute page_tempalte outside of profiler run, uninteresting to profiler
-      html = nil
-      page_template = File.basename(template_name, File.extname(template_name))
-
-      unless @started
-        RubyProf.start
-        RubyProf.pause
-        @started = true
-      end
-
-      html = nil
-
-      RubyProf.resume
-      html = compile_and_render(liquid, layout, assigns, page_template, template_name)
-      RubyProf.pause
-
-
-      # return the result and the MD5 of the content, this can be used to detect regressions between liquid version
-      $stdout.puts "* rendered template %s, content: %s" % [template_name, Digest::MD5.hexdigest(html)]
-
-      # Uncomment to dump html files to /tmp so that you can inspect for errors
-      # File.open("/tmp/#{File.basename(template_name)}.html", "w+") { |fp| fp <<html}
-    end
-
-    RubyProf.stop
-  end
-
   def compile_and_render(template, layout, assigns, page_template, template_file)
     tmpl = Liquid::Template.new
     tmpl.assigns['page_title'] = 'Page title'
     tmpl.assigns['template'] = page_template
     tmpl.registers[:file_system] = ThemeRunner::FileSystem.new(File.dirname(template_file))
 
-    content_for_layout = tmpl.parse(template).render(assigns)
+    content_for_layout = tmpl.parse(template).render!(assigns)
 
     if layout
       assigns['content_for_layout'] = content_for_layout
-      tmpl.parse(layout).render(assigns)
+      tmpl.parse(layout).render!(assigns)
     else
       content_for_layout
     end
   end
 end
-
-
-

test/integration/assign_test.rb

@@ -0,0 +1,48 @@
+require 'test_helper'
+
+class AssignTest < Minitest::Test
+  include Liquid
+
+  def test_assign_with_hyphen_in_variable_name
+    template_source = <<-END_TEMPLATE
+    {% assign this-thing = 'Print this-thing' %}
+    {{ this-thing }}
+    END_TEMPLATE
+    template = Template.parse(template_source)
+    rendered = template.render!
+    assert_equal "Print this-thing", rendered.strip
+  end
+
+  def test_assigned_variable
+    assert_template_result('.foo.',
+      '{% assign foo = values %}.{{ foo[0] }}.',
+      'values' => %w(foo bar baz))
+
+    assert_template_result('.bar.',
+      '{% assign foo = values %}.{{ foo[1] }}.',
+      'values' => %w(foo bar baz))
+  end
+
+  def test_assign_with_filter
+    assert_template_result('.bar.',
+      '{% assign foo = values | split: "," %}.{{ foo[1] }}.',
+      'values' => "foo,bar,baz")
+  end
+
+  def test_assign_syntax_error
+    assert_match_syntax_error(/assign/,
+      '{% assign foo not values %}.',
+      'values' => "foo,bar,baz")
+  end
+
+  def test_assign_uses_error_mode
+    with_error_mode(:strict) do
+      assert_raises(SyntaxError) do
+        Template.parse("{% assign foo = ('X' | downcase) %}")
+      end
+    end
+    with_error_mode(:lax) do
+      assert Template.parse("{% assign foo = ('X' | downcase) %}")
+    end
+  end
+end # AssignTest

test/integration/blank_test.rb

@@ -9,12 +9,12 @@ class FoobarTag < Liquid::Tag
 end
 
 class BlankTestFileSystem
-  def read_template_file(template_path, context)
+  def read_template_file(template_path)
     template_path
   end
 end
 
-class BlankTest < Test::Unit::TestCase
+class BlankTest < Minitest::Test
   include Liquid
   N = 10
 
@@ -31,7 +31,7 @@ class BlankTest < Test::Unit::TestCase
   end
 
   def test_new_tags_are_not_blank_by_default
-    assert_template_result(" "*N, wrap_in_for("{% foobar %}"))
+    assert_template_result(" " * N, wrap_in_for("{% foobar %}"))
   end
 
   def test_loops_are_blank
@@ -47,7 +47,7 @@ class BlankTest < Test::Unit::TestCase
   end
 
   def test_mark_as_blank_only_during_parsing
-    assert_template_result(" "*(N+1), wrap(" {% if false %} this never happens, but still, this block is not blank {% endif %}"))
+    assert_template_result(" " * (N + 1), wrap(" {% if false %} this never happens, but still, this block is not blank {% endif %}"))
   end
 
   def test_comments_are_blank
@@ -60,9 +60,9 @@ class BlankTest < Test::Unit::TestCase
 
   def test_nested_blocks_are_blank_but_only_if_all_children_are
     assert_template_result("", wrap(wrap(" ")))
-    assert_template_result("\n       but this is not "*(N+1),
-      wrap(%q{{% if true %} {% comment %} this is blank {% endcomment %} {% endif %}
-      {% if true %} but this is not {% endif %}}))
+    assert_template_result("\n       but this is not " * (N + 1),
+      wrap('{% if true %} {% comment %} this is blank {% endcomment %} {% endif %}
+      {% if true %} but this is not {% endif %}'))
   end
 
   def test_assigns_are_blank
@@ -76,31 +76,31 @@ class BlankTest < Test::Unit::TestCase
 
   def test_whitespace_is_not_blank_if_other_stuff_is_present
     body = "     x "
-    assert_template_result(body*(N+1), wrap(body))
+    assert_template_result(body * (N + 1), wrap(body))
   end
 
   def test_increment_is_not_blank
-    assert_template_result(" 0"*2*(N+1), wrap("{% assign foo = 0 %} {% increment foo %} {% decrement foo %}"))
+    assert_template_result(" 0" * 2 * (N + 1), wrap("{% assign foo = 0 %} {% increment foo %} {% decrement foo %}"))
   end
 
   def test_cycle_is_not_blank
-    assert_template_result("  "*((N+1)/2)+" ", wrap("{% cycle ' ', ' ' %}"))
+    assert_template_result("  " * ((N + 1) / 2) + " ", wrap("{% cycle ' ', ' ' %}"))
   end
 
   def test_raw_is_not_blank
-    assert_template_result("  "*(N+1), wrap(" {% raw %} {% endraw %}"))
+    assert_template_result("  " * (N + 1), wrap(" {% raw %} {% endraw %}"))
   end
 
   def test_include_is_blank
     Liquid::Template.file_system = BlankTestFileSystem.new
-    assert_equal "foobar"*(N+1), Template.parse(wrap("{% include 'foobar' %}")).render()
-    assert_equal " foobar "*(N+1), Template.parse(wrap("{% include ' foobar ' %}")).render()
-    assert_equal "   ", Template.parse(" {% include ' ' %} ").render()
+    assert_template_result "foobar" * (N + 1), wrap("{% include 'foobar' %}")
+    assert_template_result " foobar " * (N + 1), wrap("{% include ' foobar ' %}")
+    assert_template_result "   " * (N + 1), wrap(" {% include ' ' %} ")
   end
 
   def test_case_is_blank
     assert_template_result("", wrap(" {% assign foo = 'bar' %} {% case foo %} {% when 'bar' %} {% when 'whatever' %} {% else %} {% endcase %} "))
     assert_template_result("", wrap(" {% assign foo = 'else' %} {% case foo %} {% when 'bar' %} {% when 'whatever' %} {% else %} {% endcase %} "))
-    assert_template_result("   x  "*(N+1), wrap(" {% assign foo = 'else' %} {% case foo %} {% when 'bar' %} {% when 'whatever' %} {% else %} x {% endcase %} "))
+    assert_template_result("   x  " * (N + 1), wrap(" {% assign foo = 'else' %} {% case foo %} {% when 'bar' %} {% when 'whatever' %} {% else %} x {% endcase %} "))
   end
 end

test/integration/capture_test.rb

@@ -1,12 +1,22 @@
 require 'test_helper'
 
-class CaptureTest < Test::Unit::TestCase
+class CaptureTest < Minitest::Test
   include Liquid
 
   def test_captures_block_content_in_variable
     assert_template_result("test string", "{% capture 'var' %}test string{% endcapture %}{{var}}", {})
   end
 
+  def test_capture_with_hyphen_in_variable_name
+    template_source = <<-END_TEMPLATE
+    {% capture this-thing %}Print this-thing{% endcapture %}
+    {{ this-thing }}
+    END_TEMPLATE
+    template = Template.parse(template_source)
+    rendered = template.render!
+    assert_equal "Print this-thing", rendered.strip
+  end
+
   def test_capture_to_variable_from_outer_scope_if_existing
     template_source = <<-END_TEMPLATE
     {% assign var = '' %}
@@ -19,7 +29,7 @@ class CaptureTest < Test::Unit::TestCase
     {{var}}
     END_TEMPLATE
     template = Template.parse(template_source)
-    rendered = template.render
+    rendered = template.render!
     assert_equal "test-string", rendered.gsub(/\s/, '')
   end
 
@@ -34,7 +44,7 @@ class CaptureTest < Test::Unit::TestCase
     {{ first }}-{{ second }}
     END_TEMPLATE
     template = Template.parse(template_source)
-    rendered = template.render
+    rendered = template.render!
     assert_equal "3-3", rendered.gsub(/\s/, '')
   end
 end # CaptureTest

test/integration/context_test.rb

@@ -0,0 +1,32 @@
+require 'test_helper'
+
+class ContextTest < Minitest::Test
+  include Liquid
+
+  def test_override_global_filter
+    global = Module.new do
+      def notice(output)
+        "Global #{output}"
+      end
+    end
+
+    local = Module.new do
+      def notice(output)
+        "Local #{output}"
+      end
+    end
+
+    with_global_filter(global) do
+      assert_equal 'Global test', Template.parse("{{'test' | notice }}").render!
+      assert_equal 'Local test', Template.parse("{{'test' | notice }}").render!({}, filters: [local])
+    end
+  end
+
+  def test_has_key_will_not_add_an_error_for_missing_keys
+    with_error_mode :strict do
+      context = Context.new
+      context.key?('unknown')
+      assert_empty context.errors
+    end
+  end
+end

test/integration/document_test.rb

@@ -0,0 +1,19 @@
+require 'test_helper'
+
+class DocumentTest < Minitest::Test
+  include Liquid
+
+  def test_unexpected_outer_tag
+    exc = assert_raises(SyntaxError) do
+      Template.parse("{% else %}")
+    end
+    assert_equal exc.message, "Liquid syntax error: Unexpected outer 'else' tag"
+  end
+
+  def test_unknown_tag
+    exc = assert_raises(SyntaxError) do
+      Template.parse("{% foo %}")
+    end
+    assert_equal exc.message, "Liquid syntax error: Unknown tag 'foo'"
+  end
+end

test/integration/drop_test.rb

@@ -0,0 +1,271 @@
+require 'test_helper'
+
+class ContextDrop < Liquid::Drop
+  def scopes
+    @context.scopes.size
+  end
+
+  def scopes_as_array
+    (1..@context.scopes.size).to_a
+  end
+
+  def loop_pos
+    @context['forloop.index']
+  end
+
+  def before_method(method)
+    @context[method]
+  end
+end
+
+class ProductDrop < Liquid::Drop
+  class TextDrop < Liquid::Drop
+    def array
+      ['text1', 'text2']
+    end
+
+    def text
+      'text1'
+    end
+  end
+
+  class CatchallDrop < Liquid::Drop
+    def before_method(method)
+      'method: ' << method.to_s
+    end
+  end
+
+  def texts
+    TextDrop.new
+  end
+
+  def catchall
+    CatchallDrop.new
+  end
+
+  def context
+    ContextDrop.new
+  end
+
+  def user_input
+    "foo".taint
+  end
+
+  protected
+
+  def callmenot
+    "protected"
+  end
+end
+
+class EnumerableDrop < Liquid::Drop
+  def before_method(method)
+    method
+  end
+
+  def size
+    3
+  end
+
+  def first
+    1
+  end
+
+  def count
+    3
+  end
+
+  def min
+    1
+  end
+
+  def max
+    3
+  end
+
+  def each
+    yield 1
+    yield 2
+    yield 3
+  end
+end
+
+class RealEnumerableDrop < Liquid::Drop
+  include Enumerable
+
+  def before_method(method)
+    method
+  end
+
+  def each
+    yield 1
+    yield 2
+    yield 3
+  end
+end
+
+class DropsTest < Minitest::Test
+  include Liquid
+
+  def test_product_drop
+    tpl = Liquid::Template.parse('  ')
+    assert_equal '  ', tpl.render!('product' => ProductDrop.new)
+  end
+
+  def test_rendering_raises_on_tainted_attr
+    with_taint_mode(:error) do
+      tpl = Liquid::Template.parse('{{ product.user_input }}')
+      assert_raises TaintedError do
+        tpl.render!('product' => ProductDrop.new)
+      end
+    end
+  end
+
+  def test_rendering_warns_on_tainted_attr
+    with_taint_mode(:warn) do
+      tpl = Liquid::Template.parse('{{ product.user_input }}')
+      tpl.render!('product' => ProductDrop.new)
+      assert_match /tainted/, tpl.warnings.first
+    end
+  end
+
+  def test_rendering_doesnt_raise_on_escaped_tainted_attr
+    with_taint_mode(:error) do
+      tpl = Liquid::Template.parse('{{ product.user_input | escape }}')
+      tpl.render!('product' => ProductDrop.new)
+    end
+  end
+
+  def test_drop_does_only_respond_to_whitelisted_methods
+    assert_equal "", Liquid::Template.parse("{{ product.inspect }}").render!('product' => ProductDrop.new)
+    assert_equal "", Liquid::Template.parse("{{ product.pretty_inspect }}").render!('product' => ProductDrop.new)
+    assert_equal "", Liquid::Template.parse("{{ product.whatever }}").render!('product' => ProductDrop.new)
+    assert_equal "", Liquid::Template.parse('{{ product | map: "inspect" }}').render!('product' => ProductDrop.new)
+    assert_equal "", Liquid::Template.parse('{{ product | map: "pretty_inspect" }}').render!('product' => ProductDrop.new)
+    assert_equal "", Liquid::Template.parse('{{ product | map: "whatever" }}').render!('product' => ProductDrop.new)
+  end
+
+  def test_drops_respond_to_to_liquid
+    assert_equal "text1", Liquid::Template.parse("{{ product.to_liquid.texts.text }}").render!('product' => ProductDrop.new)
+    assert_equal "text1", Liquid::Template.parse('{{ product | map: "to_liquid" | map: "texts" | map: "text" }}').render!('product' => ProductDrop.new)
+  end
+
+  def test_text_drop
+    output = Liquid::Template.parse(' {{ product.texts.text }} ').render!('product' => ProductDrop.new)
+    assert_equal ' text1 ', output
+  end
+
+  def test_unknown_method
+    output = Liquid::Template.parse(' {{ product.catchall.unknown }} ').render!('product' => ProductDrop.new)
+    assert_equal ' method: unknown ', output
+  end
+
+  def test_integer_argument_drop
+    output = Liquid::Template.parse(' {{ product.catchall[8] }} ').render!('product' => ProductDrop.new)
+    assert_equal ' method: 8 ', output
+  end
+
+  def test_text_array_drop
+    output = Liquid::Template.parse('{% for text in product.texts.array %} {{text}} {% endfor %}').render!('product' => ProductDrop.new)
+    assert_equal ' text1  text2 ', output
+  end
+
+  def test_context_drop
+    output = Liquid::Template.parse(' {{ context.bar }} ').render!('context' => ContextDrop.new, 'bar' => "carrot")
+    assert_equal ' carrot ', output
+  end
+
+  def test_nested_context_drop
+    output = Liquid::Template.parse(' {{ product.context.foo }} ').render!('product' => ProductDrop.new, 'foo' => "monkey")
+    assert_equal ' monkey ', output
+  end
+
+  def test_protected
+    output = Liquid::Template.parse(' {{ product.callmenot }} ').render!('product' => ProductDrop.new)
+    assert_equal '  ', output
+  end
+
+  def test_object_methods_not_allowed
+    [:dup, :clone, :singleton_class, :eval, :class_eval, :inspect].each do |method|
+      output = Liquid::Template.parse(" {{ product.#{method} }} ").render!('product' => ProductDrop.new)
+      assert_equal '  ', output
+    end
+  end
+
+  def test_scope
+    assert_equal '1', Liquid::Template.parse('{{ context.scopes }}').render!('context' => ContextDrop.new)
+    assert_equal '2', Liquid::Template.parse('{%for i in dummy%}{{ context.scopes }}{%endfor%}').render!('context' => ContextDrop.new, 'dummy' => [1])
+    assert_equal '3', Liquid::Template.parse('{%for i in dummy%}{%for i in dummy%}{{ context.scopes }}{%endfor%}{%endfor%}').render!('context' => ContextDrop.new, 'dummy' => [1])
+  end
+
+  def test_scope_though_proc
+    assert_equal '1', Liquid::Template.parse('{{ s }}').render!('context' => ContextDrop.new, 's' => proc{ |c| c['context.scopes'] })
+    assert_equal '2', Liquid::Template.parse('{%for i in dummy%}{{ s }}{%endfor%}').render!('context' => ContextDrop.new, 's' => proc{ |c| c['context.scopes'] }, 'dummy' => [1])
+    assert_equal '3', Liquid::Template.parse('{%for i in dummy%}{%for i in dummy%}{{ s }}{%endfor%}{%endfor%}').render!('context' => ContextDrop.new, 's' => proc{ |c| c['context.scopes'] }, 'dummy' => [1])
+  end
+
+  def test_scope_with_assigns
+    assert_equal 'variable', Liquid::Template.parse('{% assign a = "variable"%}{{a}}').render!('context' => ContextDrop.new)
+    assert_equal 'variable', Liquid::Template.parse('{% assign a = "variable"%}{%for i in dummy%}{{a}}{%endfor%}').render!('context' => ContextDrop.new, 'dummy' => [1])
+    assert_equal 'test', Liquid::Template.parse('{% assign header_gif = "test"%}{{header_gif}}').render!('context' => ContextDrop.new)
+    assert_equal 'test', Liquid::Template.parse("{% assign header_gif = 'test'%}{{header_gif}}").render!('context' => ContextDrop.new)
+  end
+
+  def test_scope_from_tags
+    assert_equal '1', Liquid::Template.parse('{% for i in context.scopes_as_array %}{{i}}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1])
+    assert_equal '12', Liquid::Template.parse('{%for a in dummy%}{% for i in context.scopes_as_array %}{{i}}{% endfor %}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1])
+    assert_equal '123', Liquid::Template.parse('{%for a in dummy%}{%for a in dummy%}{% for i in context.scopes_as_array %}{{i}}{% endfor %}{% endfor %}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1])
+  end
+
+  def test_access_context_from_drop
+    assert_equal '123', Liquid::Template.parse('{%for a in dummy%}{{ context.loop_pos }}{% endfor %}').render!('context' => ContextDrop.new, 'dummy' => [1, 2, 3])
+  end
+
+  def test_enumerable_drop
+    assert_equal '123', Liquid::Template.parse('{% for c in collection %}{{c}}{% endfor %}').render!('collection' => EnumerableDrop.new)
+  end
+
+  def test_enumerable_drop_size
+    assert_equal '3', Liquid::Template.parse('{{collection.size}}').render!('collection' => EnumerableDrop.new)
+  end
+
+  def test_enumerable_drop_will_invoke_before_method_for_clashing_method_names
+    ["select", "each", "map", "cycle"].each do |method|
+      assert_equal method.to_s, Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => EnumerableDrop.new)
+      assert_equal method.to_s, Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => EnumerableDrop.new)
+      assert_equal method.to_s, Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => RealEnumerableDrop.new)
+      assert_equal method.to_s, Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => RealEnumerableDrop.new)
+    end
+  end
+
+  def test_some_enumerable_methods_still_get_invoked
+    [ :count, :max ].each do |method|
+      assert_equal "3", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => RealEnumerableDrop.new)
+      assert_equal "3", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => RealEnumerableDrop.new)
+      assert_equal "3", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => EnumerableDrop.new)
+      assert_equal "3", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => EnumerableDrop.new)
+    end
+
+    assert_equal "yes", Liquid::Template.parse("{% if collection contains 3 %}yes{% endif %}").render!('collection' => RealEnumerableDrop.new)
+
+    [ :min, :first ].each do |method|
+      assert_equal "1", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => RealEnumerableDrop.new)
+      assert_equal "1", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => RealEnumerableDrop.new)
+      assert_equal "1", Liquid::Template.parse("{{collection.#{method}}}").render!('collection' => EnumerableDrop.new)
+      assert_equal "1", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render!('collection' => EnumerableDrop.new)
+    end
+  end
+
+  def test_empty_string_value_access
+    assert_equal '', Liquid::Template.parse('{{ product[value] }}').render!('product' => ProductDrop.new, 'value' => '')
+  end
+
+  def test_nil_value_access
+    assert_equal '', Liquid::Template.parse('{{ product[value] }}').render!('product' => ProductDrop.new, 'value' => nil)
+  end
+
+  def test_default_to_s_on_drops
+    assert_equal 'ProductDrop', Liquid::Template.parse("{{ product }}").render!('product' => ProductDrop.new)
+    assert_equal 'EnumerableDrop', Liquid::Template.parse('{{ collection }}').render!('collection' => EnumerableDrop.new)
+  end
+end # DropsTest

test/integration/error_handling_test.rb

@@ -0,0 +1,226 @@
+require 'test_helper'
+
+class ErrorHandlingTest < Minitest::Test
+  include Liquid
+
+  def test_templates_parsed_with_line_numbers_renders_them_in_errors
+    template = <<-LIQUID
+      Hello,
+
+      {{ errors.standard_error }} will raise a standard error.
+
+      Bla bla test.
+
+      {{ errors.syntax_error }} will raise a syntax error.
+
+      This is an argument error: {{ errors.argument_error }}
+
+      Bla.
+    LIQUID
+
+    expected = <<-TEXT
+      Hello,
+
+      Liquid error (line 3): standard error will raise a standard error.
+
+      Bla bla test.
+
+      Liquid syntax error (line 7): syntax error will raise a syntax error.
+
+      This is an argument error: Liquid error (line 9): argument error
+
+      Bla.
+    TEXT
+
+    output = Liquid::Template.parse(template, line_numbers: true).render('errors' => ErrorDrop.new)
+    assert_equal expected, output
+  end
+
+  def test_standard_error
+    template = Liquid::Template.parse(' {{ errors.standard_error }} ')
+    assert_equal ' Liquid error: standard error ', template.render('errors' => ErrorDrop.new)
+
+    assert_equal 1, template.errors.size
+    assert_equal StandardError, template.errors.first.class
+  end
+
+  def test_syntax
+    template = Liquid::Template.parse(' {{ errors.syntax_error }} ')
+    assert_equal ' Liquid syntax error: syntax error ', template.render('errors' => ErrorDrop.new)
+
+    assert_equal 1, template.errors.size
+    assert_equal SyntaxError, template.errors.first.class
+  end
+
+  def test_argument
+    template = Liquid::Template.parse(' {{ errors.argument_error }} ')
+    assert_equal ' Liquid error: argument error ', template.render('errors' => ErrorDrop.new)
+
+    assert_equal 1, template.errors.size
+    assert_equal ArgumentError, template.errors.first.class
+  end
+
+  def test_missing_endtag_parse_time_error
+    assert_raises(Liquid::SyntaxError) do
+      Liquid::Template.parse(' {% for a in b %} ... ')
+    end
+  end
+
+  def test_unrecognized_operator
+    with_error_mode(:strict) do
+      assert_raises(SyntaxError) do
+        Liquid::Template.parse(' {% if 1 =! 2 %}ok{% endif %} ')
+      end
+    end
+  end
+
+  def test_lax_unrecognized_operator
+    template = Liquid::Template.parse(' {% if 1 =! 2 %}ok{% endif %} ', error_mode: :lax)
+    assert_equal ' Liquid error: Unknown operator =! ', template.render
+    assert_equal 1, template.errors.size
+    assert_equal Liquid::ArgumentError, template.errors.first.class
+  end
+
+  def test_with_line_numbers_adds_numbers_to_parser_errors
+    err = assert_raises(SyntaxError) do
+      Liquid::Template.parse(%q(
+          foobar
+
+          {% "cat" | foobar %}
+
+          bla
+        ),
+        line_numbers: true
+      )
+    end
+
+    assert_match /Liquid syntax error \(line 4\)/, err.message
+  end
+
+  def test_parsing_warn_with_line_numbers_adds_numbers_to_lexer_errors
+    template = Liquid::Template.parse('
+        foobar
+
+        {% if 1 =! 2 %}ok{% endif %}
+
+        bla
+            ',
+      error_mode: :warn,
+      line_numbers: true
+                                     )
+
+    assert_equal ['Liquid syntax error (line 4): Unexpected character = in "1 =! 2"'],
+      template.warnings.map(&:message)
+  end
+
+  def test_parsing_strict_with_line_numbers_adds_numbers_to_lexer_errors
+    err = assert_raises(SyntaxError) do
+      Liquid::Template.parse('
+          foobar
+
+          {% if 1 =! 2 %}ok{% endif %}
+
+          bla
+                ',
+        error_mode: :strict,
+        line_numbers: true
+                            )
+    end
+
+    assert_equal 'Liquid syntax error (line 4): Unexpected character = in "1 =! 2"', err.message
+  end
+
+  def test_syntax_errors_in_nested_blocks_have_correct_line_number
+    err = assert_raises(SyntaxError) do
+      Liquid::Template.parse('
+          foobar
+
+          {% if 1 != 2 %}
+            {% foo %}
+          {% endif %}
+
+          bla
+                ',
+        line_numbers: true
+                            )
+    end
+
+    assert_equal "Liquid syntax error (line 5): Unknown tag 'foo'", err.message
+  end
+
+  def test_strict_error_messages
+    err = assert_raises(SyntaxError) do
+      Liquid::Template.parse(' {% if 1 =! 2 %}ok{% endif %} ', error_mode: :strict)
+    end
+    assert_equal 'Liquid syntax error: Unexpected character = in "1 =! 2"', err.message
+
+    err = assert_raises(SyntaxError) do
+      Liquid::Template.parse('{{%%%}}', error_mode: :strict)
+    end
+    assert_equal 'Liquid syntax error: Unexpected character % in "{{%%%}}"', err.message
+  end
+
+  def test_warnings
+    template = Liquid::Template.parse('{% if ~~~ %}{{%%%}}{% else %}{{ hello. }}{% endif %}', error_mode: :warn)
+    assert_equal 3, template.warnings.size
+    assert_equal 'Unexpected character ~ in "~~~"', template.warnings[0].to_s(false)
+    assert_equal 'Unexpected character % in "{{%%%}}"', template.warnings[1].to_s(false)
+    assert_equal 'Expected id but found end_of_string in "{{ hello. }}"', template.warnings[2].to_s(false)
+    assert_equal '', template.render
+  end
+
+  def test_warning_line_numbers
+    template = Liquid::Template.parse("{% if ~~~ %}\n{{%%%}}{% else %}\n{{ hello. }}{% endif %}", error_mode: :warn, line_numbers: true)
+    assert_equal 'Liquid syntax error (line 1): Unexpected character ~ in "~~~"', template.warnings[0].message
+    assert_equal 'Liquid syntax error (line 2): Unexpected character % in "{{%%%}}"', template.warnings[1].message
+    assert_equal 'Liquid syntax error (line 3): Expected id but found end_of_string in "{{ hello. }}"', template.warnings[2].message
+    assert_equal 3, template.warnings.size
+    assert_equal [1, 2, 3], template.warnings.map(&:line_number)
+  end
+
+  # Liquid should not catch Exceptions that are not subclasses of StandardError, like Interrupt and NoMemoryError
+  def test_exceptions_propagate
+    assert_raises Exception do
+      template = Liquid::Template.parse('{{ errors.exception }}')
+      template.render('errors' => ErrorDrop.new)
+    end
+  end
+
+  def test_exception_handler_with_string_result
+    template = Liquid::Template.parse('This is an argument error: {{ errors.argument_error }}')
+    output = template.render({ 'errors' => ErrorDrop.new }, exception_handler: ->(e) { '' })
+    assert_equal 'This is an argument error: ', output
+    assert_equal [ArgumentError], template.errors.map(&:class)
+  end
+
+  class InternalError < Liquid::Error
+  end
+
+  def test_exception_handler_with_exception_result
+    template = Liquid::Template.parse('This is a runtime error: {{ errors.runtime_error }}', line_numbers: true)
+    handler = ->(e) { e.is_a?(Liquid::Error) ? e : InternalError.new('internal') }
+    output = template.render({ 'errors' => ErrorDrop.new }, exception_handler: handler)
+    assert_equal 'This is a runtime error: Liquid error (line 1): internal', output
+    assert_equal [InternalError], template.errors.map(&:class)
+  end
+
+  class TestFileSystem
+    def read_template_file(template_path)
+      "{{ errors.argument_error }}"
+    end
+  end
+
+  def test_included_template_name_with_line_numbers
+    old_file_system = Liquid::Template.file_system
+
+    begin
+      Liquid::Template.file_system = TestFileSystem.new
+      template = Liquid::Template.parse("Argument error:\n{% include 'product' %}", line_numbers: true)
+      page = template.render('errors' => ErrorDrop.new)
+    ensure
+      Liquid::Template.file_system = old_file_system
+    end
+    assert_equal "Argument error:\nLiquid error (product line 1): argument error", page
+    assert_equal "product", template.errors.first.template_name
+  end
+end

test/integration/filter_test.rb

@@ -0,0 +1,189 @@
+require 'test_helper'
+
+module MoneyFilter
+  def money(input)
+    sprintf(' %d$ ', input)
+  end
+
+  def money_with_underscore(input)
+    sprintf(' %d$ ', input)
+  end
+end
+
+module CanadianMoneyFilter
+  def money(input)
+    sprintf(' %d$ CAD ', input)
+  end
+end
+
+module SubstituteFilter
+  def substitute(input, params = {})
+    input.gsub(/%\{(\w+)\}/) { |match| params[$1] }
+  end
+end
+
+class FiltersTest < Minitest::Test
+  include Liquid
+
+  module OverrideObjectMethodFilter
+    def tap(input)
+      "tap overridden"
+    end
+  end
+
+  def setup
+    @context = Context.new
+  end
+
+  def test_local_filter
+    @context['var'] = 1000
+    @context.add_filters(MoneyFilter)
+
+    assert_equal ' 1000$ ', Variable.new("var | money").render(@context)
+  end
+
+  def test_underscore_in_filter_name
+    @context['var'] = 1000
+    @context.add_filters(MoneyFilter)
+    assert_equal ' 1000$ ', Variable.new("var | money_with_underscore").render(@context)
+  end
+
+  def test_second_filter_overwrites_first
+    @context['var'] = 1000
+    @context.add_filters(MoneyFilter)
+    @context.add_filters(CanadianMoneyFilter)
+
+    assert_equal ' 1000$ CAD ', Variable.new("var | money").render(@context)
+  end
+
+  def test_size
+    @context['var'] = 'abcd'
+    @context.add_filters(MoneyFilter)
+
+    assert_equal 4, Variable.new("var | size").render(@context)
+  end
+
+  def test_join
+    @context['var'] = [1, 2, 3, 4]
+
+    assert_equal "1 2 3 4", Variable.new("var | join").render(@context)
+  end
+
+  def test_sort
+    @context['value'] = 3
+    @context['numbers'] = [2, 1, 4, 3]
+    @context['words'] = ['expected', 'as', 'alphabetic']
+    @context['arrays'] = ['flower', 'are']
+    @context['case_sensitive'] = ['sensitive', 'Expected', 'case']
+
+    assert_equal [1, 2, 3, 4], Variable.new("numbers | sort").render(@context)
+    assert_equal ['alphabetic', 'as', 'expected'], Variable.new("words | sort").render(@context)
+    assert_equal [3], Variable.new("value | sort").render(@context)
+    assert_equal ['are', 'flower'], Variable.new("arrays | sort").render(@context)
+    assert_equal ['Expected', 'case', 'sensitive'], Variable.new("case_sensitive | sort").render(@context)
+  end
+
+  def test_sort_natural
+    @context['words'] = ['case', 'Assert', 'Insensitive']
+    @context['hashes'] = [{ 'a' => 'A' }, { 'a' => 'b' }, { 'a' => 'C' }]
+    @context['objects'] = [TestObject.new('A'), TestObject.new('b'), TestObject.new('C')]
+
+    # Test strings
+    assert_equal ['Assert', 'case', 'Insensitive'], Variable.new("words | sort_natural").render(@context)
+
+    # Test hashes
+    sorted = Variable.new("hashes | sort_natural: 'a'").render(@context)
+    assert_equal sorted[0]['a'], 'A'
+    assert_equal sorted[1]['a'], 'b'
+    assert_equal sorted[2]['a'], 'C'
+
+    # Test objects
+    sorted = Variable.new("objects | sort_natural: 'a'").render(@context)
+    assert_equal sorted[0].a, 'A'
+    assert_equal sorted[1].a, 'b'
+    assert_equal sorted[2].a, 'C'
+  end
+
+  def test_compact
+    @context['words'] = ['a', nil, 'b', nil, 'c']
+    @context['hashes'] = [{ 'a' => 'A' }, { 'a' => nil }, { 'a' => 'C' }]
+    @context['objects'] = [TestObject.new('A'), TestObject.new(nil), TestObject.new('C')]
+
+    # Test strings
+    assert_equal ['a', 'b', 'c'], Variable.new("words | compact").render(@context)
+
+    # Test hashes
+    sorted = Variable.new("hashes | compact: 'a'").render(@context)
+    assert_equal sorted[0]['a'], 'A'
+    assert_equal sorted[1]['a'], 'C'
+    assert_nil sorted[2]
+
+    # Test objects
+    sorted = Variable.new("objects | compact: 'a'").render(@context)
+    assert_equal sorted[0].a, 'A'
+    assert_equal sorted[1].a, 'C'
+    assert_nil sorted[2]
+  end
+
+  def test_strip_html
+    @context['var'] = "<b>bla blub</a>"
+
+    assert_equal "bla blub", Variable.new("var | strip_html").render(@context)
+  end
+
+  def test_strip_html_ignore_comments_with_html
+    @context['var'] = "<!-- split and some <ul> tag --><b>bla blub</a>"
+
+    assert_equal "bla blub", Variable.new("var | strip_html").render(@context)
+  end
+
+  def test_capitalize
+    @context['var'] = "blub"
+
+    assert_equal "Blub", Variable.new("var | capitalize").render(@context)
+  end
+
+  def test_nonexistent_filter_is_ignored
+    @context['var'] = 1000
+
+    assert_equal 1000, Variable.new("var | xyzzy").render(@context)
+  end
+
+  def test_filter_with_keyword_arguments
+    @context['surname'] = 'john'
+    @context.add_filters(SubstituteFilter)
+    output = Variable.new(%( 'hello %{first_name}, %{last_name}' | substitute: first_name: surname, last_name: 'doe' )).render(@context)
+    assert_equal 'hello john, doe', output
+  end
+
+  def test_override_object_method_in_filter
+    assert_equal "tap overridden", Template.parse("{{var | tap}}").render!({ 'var' => 1000 }, filters: [OverrideObjectMethodFilter])
+
+    # tap still treated as a non-existent filter
+    assert_equal "1000", Template.parse("{{var | tap}}").render!({ 'var' => 1000 })
+  end
+end
+
+class FiltersInTemplate < Minitest::Test
+  include Liquid
+
+  def test_local_global
+    with_global_filter(MoneyFilter) do
+      assert_equal " 1000$ ", Template.parse("{{1000 | money}}").render!(nil, nil)
+      assert_equal " 1000$ CAD ", Template.parse("{{1000 | money}}").render!(nil, filters: CanadianMoneyFilter)
+      assert_equal " 1000$ CAD ", Template.parse("{{1000 | money}}").render!(nil, filters: [CanadianMoneyFilter])
+    end
+  end
+
+  def test_local_filter_with_deprecated_syntax
+    assert_equal " 1000$ CAD ", Template.parse("{{1000 | money}}").render!(nil, CanadianMoneyFilter)
+    assert_equal " 1000$ CAD ", Template.parse("{{1000 | money}}").render!(nil, [CanadianMoneyFilter])
+  end
+end # FiltersTest
+
+class TestObject
+  attr_accessor :a
+  def initialize(a)
+    @a = a
+  end
+end

test/integration/hash_ordering_test.rb

@@ -0,0 +1,23 @@
+require 'test_helper'
+
+module MoneyFilter
+  def money(input)
+    sprintf(' %d$ ', input)
+  end
+end
+
+module CanadianMoneyFilter
+  def money(input)
+    sprintf(' %d$ CAD ', input)
+  end
+end
+
+class HashOrderingTest < Minitest::Test
+  include Liquid
+
+  def test_global_register_order
+    with_global_filter(MoneyFilter, CanadianMoneyFilter) do
+      assert_equal " 1000$ CAD ", Template.parse("{{1000 | money}}").render(nil, nil)
+    end
+  end
+end

test/integration/output_test.rb

@@ -0,0 +1,115 @@
+require 'test_helper'
+
+module FunnyFilter
+  def make_funny(input)
+    'LOL'
+  end
+
+  def cite_funny(input)
+    "LOL: #{input}"
+  end
+
+  def add_smiley(input, smiley = ":-)")
+    "#{input} #{smiley}"
+  end
+
+  def add_tag(input, tag = "p", id = "foo")
+    %(<#{tag} id="#{id}">#{input}</#{tag}>)
+  end
+
+  def paragraph(input)
+    "<p>#{input}</p>"
+  end
+
+  def link_to(name, url)
+    %(<a href="#{url}">#{name}</a>)
+  end
+end
+
+class OutputTest < Minitest::Test
+  include Liquid
+
+  def setup
+    @assigns = {
+      'best_cars' => 'bmw',
+      'car' => { 'bmw' => 'good', 'gm' => 'bad' }
+    }
+  end
+
+  def test_variable
+    text = %( {{best_cars}} )
+
+    expected = %( bmw )
+    assert_equal expected, Template.parse(text).render!(@assigns)
+  end
+
+  def test_variable_traversing
+    text = %( {{car.bmw}} {{car.gm}} {{car.bmw}} )
+
+    expected = %( good bad good )
+    assert_equal expected, Template.parse(text).render!(@assigns)
+  end
+
+  def test_variable_piping
+    text = %( {{ car.gm | make_funny }} )
+    expected = %( LOL )
+
+    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+  end
+
+  def test_variable_piping_with_input
+    text = %( {{ car.gm | cite_funny }} )
+    expected = %( LOL: bad )
+
+    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+  end
+
+  def test_variable_piping_with_args
+    text = %! {{ car.gm | add_smiley : ':-(' }} !
+    expected = %| bad :-( |
+
+    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+  end
+
+  def test_variable_piping_with_no_args
+    text = %( {{ car.gm | add_smiley }} )
+    expected = %| bad :-) |
+
+    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+  end
+
+  def test_multiple_variable_piping_with_args
+    text = %! {{ car.gm | add_smiley : ':-(' | add_smiley : ':-('}} !
+    expected = %| bad :-( :-( |
+
+    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+  end
+
+  def test_variable_piping_with_multiple_args
+    text = %( {{ car.gm | add_tag : 'span', 'bar'}} )
+    expected = %( <span id="bar">bad</span> )
+
+    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+  end
+
+  def test_variable_piping_with_variable_args
+    text = %( {{ car.gm | add_tag : 'span', car.bmw}} )
+    expected = %( <span id="good">bad</span> )
+
+    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+  end
+
+  def test_multiple_pipings
+    text = %( {{ best_cars | cite_funny | paragraph }} )
+    expected = %( <p>LOL: bmw</p> )
+
+    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+  end
+
+  def test_link_to
+    text = %( {{ 'Typo' | link_to: 'http://typo.leetsoft.com' }} )
+    expected = %( <a href="http://typo.leetsoft.com">Typo</a> )
+
+    assert_equal expected, Template.parse(text).render!(@assigns, filters: [FunnyFilter])
+  end
+end # OutputTest