From b242a7273aadfbc910522ac1033afc2a6dc40045 Mon Sep 17 00:00:00 2001
From: Florian Weingarten <flo@hackvalue.de>
Date: Fri, 7 Nov 2014 01:48:05 +0000
Subject: [PATCH] Revert "Merge pull request #478 from
 Shopify/numbers-in-identifiers"

This reverts commit 263e90e7725586b66339eda953c8e6fbc7af8a6f, reversing
changes made to 4dc682313f1d3159eca28dffbe9206ef4879078c.
---
 lib/liquid/lexer.rb             |  2 +-
 lib/liquid/parser.rb            |  7 +++++++
 lib/liquid/variable.rb          |  8 ++++++++
 test/unit/lexer_unit_test.rb    |  5 +----
 test/unit/variable_unit_test.rb | 11 -----------
 5 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/lib/liquid/lexer.rb b/lib/liquid/lexer.rb
index 4b724b1..cb8e591 100644
--- a/lib/liquid/lexer.rb
+++ b/lib/liquid/lexer.rb
@@ -13,7 +13,7 @@ module Liquid
       '?'.freeze => :question,
       '-'.freeze => :dash
     }
-    IDENTIFIER = /[a-zA-Z_][\w-]*\??/
+    IDENTIFIER = /\w+/
     SINGLE_STRING_LITERAL = /'[^\']*'/
     DOUBLE_STRING_LITERAL = /"[^\"]*"/
     NUMBER_LITERAL = /-?\d+(\.\d+)?/
diff --git a/lib/liquid/parser.rb b/lib/liquid/parser.rb
index d2006f3..ecf3634 100644
--- a/lib/liquid/parser.rb
+++ b/lib/liquid/parser.rb
@@ -75,6 +75,13 @@ module Liquid
 
     def variable_signature
       str = consume(:id)
+      while consume?(:dash)
+        str << "-".freeze
+        str << consume(:id)
+      end
+      if consume?(:question)
+        str << "?".freeze
+      end
       if look(:open_square)
         str << consume
         str << expression
diff --git a/lib/liquid/variable.rb b/lib/liquid/variable.rb
index 92b0537..a93fed7 100644
--- a/lib/liquid/variable.rb
+++ b/lib/liquid/variable.rb
@@ -12,6 +12,7 @@ module Liquid
   #
   class Variable
     FilterParser = /(?:\s+|#{QuotedFragment}|#{ArgumentSeparator})+/o
+    EasyParse = /\A *(\w+(?:\.\w+)*) *\z/
     attr_accessor :filters, :name, :warnings
     attr_accessor :line_number
     include ParserSwitching
@@ -52,6 +53,13 @@ module Liquid
     end
 
     def strict_parse(markup)
+      # Very simple valid cases
+      if markup =~ EasyParse
+        @name = Expression.parse($1)
+        @filters = []
+        return
+      end
+
       @filters = []
       p = Parser.new(markup)
 
diff --git a/test/unit/lexer_unit_test.rb b/test/unit/lexer_unit_test.rb
index c331380..ef341a1 100644
--- a/test/unit/lexer_unit_test.rb
+++ b/test/unit/lexer_unit_test.rb
@@ -32,10 +32,7 @@ class LexerUnitTest < Minitest::Test
 
   def test_fancy_identifiers
     tokens = Lexer.new('hi five?').tokenize
-    assert_equal [[:id, 'hi'], [:id, 'five?'], [:end_of_string]], tokens
-
-    tokens = Lexer.new('2foo').tokenize
-    assert_equal [[:number, '2'], [:id, 'foo'], [:end_of_string]], tokens
+    assert_equal [[:id,'hi'], [:id, 'five'], [:question, '?'], [:end_of_string]], tokens
   end
 
   def test_whitespace
diff --git a/test/unit/variable_unit_test.rb b/test/unit/variable_unit_test.rb
index 084b846..13d2cc4 100644
--- a/test/unit/variable_unit_test.rb
+++ b/test/unit/variable_unit_test.rb
@@ -102,17 +102,6 @@ class VariableUnitTest < Minitest::Test
     assert_equal 1000.01, var.name
   end
 
-  def test_dashes
-    assert_equal VariableLookup.new('foo-bar'), Variable.new('foo-bar').name
-    assert_equal VariableLookup.new('foo-bar-2'), Variable.new('foo-bar-2').name
-
-    with_error_mode :strict do
-      assert_raises(Liquid::SyntaxError) { Variable.new('foo - bar') }
-      assert_raises(Liquid::SyntaxError) { Variable.new('-foo') }
-      assert_raises(Liquid::SyntaxError) { Variable.new('2foo') }
-    end
-  end
-
   def test_string_with_special_chars
     var = Variable.new(%| 'hello! $!@.;"ddasd" ' |)
     assert_equal 'hello! $!@.;"ddasd" ', var.name