Use StringSlice.join on the rendered results.

If we are trying to get the struct from something other than self, then we
should make sure to check the class of the object.  This util functions
make this easier.

.gitignore

@@ -5,3 +5,6 @@ pkg
 *.rbc
 .rvmrc
 .ruby-version
+*.bundle
+/tmp
+Gemfile.lock

Gemfile

@@ -0,0 +1,3 @@
+source 'https://rubygems.org'
+
+gemspec

Rakefile

@@ -1,5 +1,6 @@
 require 'rake'
 require 'rake/testtask'
+require 'rake/extensiontask'
 $LOAD_PATH.unshift File.expand_path("../lib", __FILE__)
 require "liquid/version"
 
@@ -64,6 +65,10 @@ namespace :profile do
     ruby "./performance/profile.rb"
   end
 
+  task :stackprof do
+    ruby "./performance/stackprof.rb"
+  end
+
   desc "Run KCacheGrind"
   task :grind => :run  do
     system "qcachegrind /tmp/liquid.rubyprof_calltreeprinter.txt"
@@ -75,3 +80,8 @@ desc "Run example"
 task :example do
   ruby "-w -d -Ilib example/server/server.rb"
 end
+
+Rake::ExtensionTask.new "liquid" do |ext|
+  ext.lib_dir = "lib/liquid"
+end
+Rake::Task[:test].prerequisites << :compile

example/server/liquid_servlet.rb

@@ -13,7 +13,7 @@ class LiquidServlet < WEBrick::HTTPServlet::AbstractServlet
   def handle(type, req, res)
     @request, @response = req, res
 
-    @request.path_info =~ /(\w+)$/
+    @request.path_info =~ /(\w+)\z/
     @action = $1 || 'index'
     @assigns = send(@action) if respond_to?(@action)
 

ext/liquid/block.c

@@ -0,0 +1,167 @@
+#include "liquid_ext.h"
+
+VALUE cLiquidBlock;
+ID intern_assert_missing_delimitation, intern_block_delimiter, intern_is_blank,
+   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, liquid_string_slice_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_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

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

ext/liquid/extconf.rb

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

ext/liquid/liquid_ext.c

@@ -0,0 +1,18 @@
+#include "liquid_ext.h"
+
+VALUE mLiquid;
+VALUE cLiquidTemplate, cLiquidTag, cLiquidVariable;
+ID intern_new;
+
+void Init_liquid(void)
+{
+    intern_new = rb_intern("new");
+    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_string_slice();
+}

ext/liquid/liquid_ext.h

@@ -0,0 +1,17 @@
+#ifndef LIQUID_EXT_H
+#define LIQUID_EXT_H
+
+#include <stdbool.h>
+#include <ctype.h>
+#include <ruby.h>
+
+#include "tokenizer.h"
+#include "block.h"
+#include "slice.h"
+#include "utils.h"
+
+extern ID intern_new;
+extern VALUE mLiquid;
+extern VALUE cLiquidTemplate, cLiquidTag, cLiquidVariable;
+
+#endif

ext/liquid/slice.c

@@ -0,0 +1,167 @@
+#include "liquid_ext.h"
+
+VALUE cLiquidStringSlice;
+
+static void mark_slice(void *ptr)
+{
+    if (!ptr)
+        return;
+    struct string_slice *slice = ptr;
+    rb_gc_mark(slice->source);
+}
+
+static void free_slice(void *ptr)
+{
+    struct string_slice *slice = ptr;
+    xfree(slice);
+}
+
+VALUE liquid_string_slice_new(const char *str, long length)
+{
+    return rb_funcall(cLiquidStringSlice, intern_new, 3, rb_str_new(str, length), INT2FIX(0), INT2FIX(length));
+}
+
+static VALUE rb_allocate(VALUE klass)
+{
+    struct string_slice *slice;
+    VALUE obj = Data_Make_Struct(klass, struct string_slice, mark_slice, free_slice, slice);
+    return obj;
+}
+
+static VALUE rb_initialize(VALUE self, VALUE source, VALUE offset_value, VALUE length_value)
+{
+    long offset = rb_fix2int(offset_value);
+    long length = rb_fix2int(length_value);
+    if (length < 0)
+        rb_raise(rb_eArgError, "negative string length");
+    if (offset < 0)
+        rb_raise(rb_eArgError, "negative string offset");
+
+    if (TYPE(source) == T_DATA && RBASIC_CLASS(source) == cLiquidStringSlice) {
+        struct string_slice *source_slice = DATA_PTR(source);
+        source = source_slice->source;
+        offset += source_slice->str - RSTRING_PTR(source);
+    } else {
+        source = rb_string_value(&source);
+        source = rb_str_dup_frozen(source);
+    }
+
+    struct string_slice *slice;
+    Data_Get_Struct(self, struct string_slice, slice);
+    slice->source = source;
+    slice->str = RSTRING_PTR(source) + offset;
+    slice->length = length;
+    if (length > RSTRING_LEN(source) - offset)
+        rb_raise(rb_eArgError, "slice bounds outside source string bounds");
+
+    return Qnil;
+}
+
+static VALUE rb_slice_to_str(VALUE self)
+{
+    struct string_slice *slice;
+    Data_Get_Struct(self, struct string_slice, slice);
+
+    VALUE source = slice->source;
+    if (slice->str == RSTRING_PTR(source) && slice->length == RSTRING_LEN(source))
+        return source;
+
+    source = rb_str_new(slice->str, slice->length);
+    slice->source = source;
+    slice->str = RSTRING_PTR(source);
+    return source;
+}
+
+static VALUE rb_slice_slice(VALUE self, VALUE offset, VALUE length)
+{
+    return rb_funcall(cLiquidStringSlice, intern_new, 3, self, offset, length);
+}
+
+static VALUE rb_slice_length(VALUE self)
+{
+    struct string_slice *slice;
+    Data_Get_Struct(self, struct string_slice, slice);
+    return INT2FIX(slice->length);
+}
+
+static VALUE rb_slice_equal(VALUE self, VALUE other)
+{
+    struct string_slice *this_slice;
+    Data_Get_Struct(self, struct string_slice, this_slice);
+
+    const char *other_str;
+    long other_length;
+    if (TYPE(other) == T_DATA && RBASIC_CLASS(other) == cLiquidStringSlice) {
+        struct string_slice *other_slice = DATA_PTR(other);
+        other_str = other_slice->str;
+        other_length = other_slice->length;
+    } else {
+        other = rb_string_value(&other);
+        other_length = RSTRING_LEN(other);
+        other_str = RSTRING_PTR(other);
+    }
+    bool equal = this_slice->length == other_length && !memcmp(this_slice->str, other_str, other_length);
+    return equal ? Qtrue : Qfalse;
+}
+
+static VALUE rb_slice_inspect(VALUE self)
+{
+    VALUE quoted = rb_str_inspect(rb_slice_to_str(self));
+    return rb_sprintf("#<Liquid::StringSlice: %.*s>", (int)RSTRING_LEN(quoted), RSTRING_PTR(quoted));
+}
+
+static VALUE rb_slice_join(VALUE klass, VALUE ary)
+{
+    ary = rb_ary_to_ary(ary);
+
+    long i;
+    long result_length = 0;
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+        VALUE element = RARRAY_AREF(ary, i);
+
+        if (TYPE(element) == T_DATA && RBASIC_CLASS(element) == cLiquidStringSlice) {
+            struct string_slice *slice = DATA_PTR(element);
+            result_length += slice->length;
+        } else if (TYPE(element) == T_STRING) {
+            result_length += RSTRING_LEN(element);
+        }
+    }
+
+    VALUE result = rb_str_buf_new(result_length);
+    for (i = 0; i < RARRAY_LEN(ary); i++) {
+        VALUE element = RARRAY_AREF(ary, i);
+
+        const char *element_string;
+        long element_length;
+        if (TYPE(element) == T_DATA && RBASIC_CLASS(element) == cLiquidStringSlice) {
+            struct string_slice *slice = DATA_PTR(element);
+            element_string = slice->str;
+            element_length = slice->length;
+        } else if (NIL_P(element)) {
+            continue;
+        } else {
+            element = rb_check_string_type(element);
+            if (NIL_P(element))
+                continue;
+            element_string = RSTRING_PTR(element);
+            element_length = RSTRING_LEN(element);
+        }
+        rb_str_buf_cat(result, element_string, element_length);
+    }
+    return result;
+}
+
+void init_liquid_string_slice()
+{
+    cLiquidStringSlice = rb_define_class_under(mLiquid, "StringSlice", rb_cObject);
+    rb_define_singleton_method(cLiquidStringSlice, "join", rb_slice_join, 1);
+    rb_define_alloc_func(cLiquidStringSlice, rb_allocate);
+    rb_define_method(cLiquidStringSlice, "initialize", rb_initialize, 3);
+    rb_define_method(cLiquidStringSlice, "==", rb_slice_equal, 1);
+    rb_define_method(cLiquidStringSlice, "length", rb_slice_length, 0);
+    rb_define_alias(cLiquidStringSlice,  "size", "length");
+    rb_define_method(cLiquidStringSlice, "slice", rb_slice_slice, 2);
+    rb_define_method(cLiquidStringSlice, "to_str", rb_slice_to_str, 0);
+    rb_define_alias(cLiquidStringSlice,  "to_s", "to_str");
+    rb_define_method(cLiquidStringSlice, "inspect", rb_slice_inspect, 0);
+}

ext/liquid/slice.h

@@ -0,0 +1,18 @@
+#ifndef LIQUID_SLICE_H
+#define LIQUID_SLICE_H
+
+extern VALUE cLiquidStringSlice;
+
+struct string_slice {
+    VALUE source;
+    const char *str;
+    long length;
+};
+
+VALUE liquid_string_slice_new(const char *str, long length);
+
+void init_liquid_string_slice();
+
+#define STRING_SLICE_GET_STRUCT(obj) ((struct string_slice *)obj_get_data_ptr(obj, cLiquidStringSlice))
+
+#endif

ext/liquid/tokenizer.c

@@ -0,0 +1,113 @@
+#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;
+
+    source = rb_string_value(&source);
+    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

@@ -0,0 +1,30 @@
+#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

@@ -0,0 +1,21 @@
+#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

@@ -0,0 +1,8 @@
+#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

lib/liquid.rb

@@ -30,21 +30,18 @@ module Liquid
   VariableSegment             = /[\w\-]/
   VariableStart               = /\{\{/
   VariableEnd                 = /\}\}/
-  VariableIncompleteEnd       = /\}\}?/
   QuotedString                = /"[^"]*"|'[^']*'/
   QuotedFragment              = /#{QuotedString}|(?:[^\s,\|'"]|#{QuotedString})+/o
   StrictQuotedFragment        = /"[^"]+"|'[^']+'|[^\s|:,]+/
   FirstFilterArgument         = /#{FilterArgumentSeparator}(?:#{StrictQuotedFragment})/o
   OtherFilterArgument         = /#{ArgumentSeparator}(?:#{StrictQuotedFragment})/o
-  SpacelessFilter             = /^(?:'[^']+'|"[^"]+"|[^'"])*#{FilterSeparator}(?:#{StrictQuotedFragment})(?:#{FirstFilterArgument}(?:#{OtherFilterArgument})*)?/o
+  SpacelessFilter             = /\A(?:'[^']+'|"[^"]+"|[^'"])*#{FilterSeparator}(?:#{StrictQuotedFragment})(?:#{FirstFilterArgument}(?:#{OtherFilterArgument})*)?/o
   Expression                  = /(?:#{QuotedFragment}(?:#{SpacelessFilter})*)/o
   TagAttributes               = /(\w+)\s*\:\s*(#{QuotedFragment})/o
-  AnyStartingTag              = /\{\{|\{\%/
-  PartialTemplateParser       = /#{TagStart}.*?#{TagEnd}|#{VariableStart}.*?#{VariableIncompleteEnd}/o
-  TemplateParser              = /(#{PartialTemplateParser}|#{AnyStartingTag})/o
   VariableParser              = /\[[^\]]+\]|#{VariableSegment}+\??/o
 end
 
+require 'liquid/liquid'
 require "liquid/version"
 require 'liquid/lexer'
 require 'liquid/parser'

lib/liquid/block.rb

@@ -1,82 +1,26 @@
 module Liquid
   class Block < Tag
-    IsTag             = /^#{TagStart}/o
-    IsVariable        = /^#{VariableStart}/o
-    FullToken         = /^#{TagStart}\s*(\w+)\s*(.*)?#{TagEnd}$/o
-    ContentOfVariable = /^#{VariableStart}(.*)#{VariableEnd}$/o
+    def initialize(tag_name, markup, tokens)
+      super
+      parse_body(tokens)
+    end
 
     def blank?
       @blank || false
     end
 
-    def parse(tokens)
-      @blank = true
-      @nodelist ||= []
-      @nodelist.clear
-
-      # All child tags of the current block.
-      @children = []
-
-      while token = tokens.shift
-        case token
-        when IsTag
-          if token =~ FullToken
-
-            # if we found the proper block delimiter just end parsing here and let the outer block
-            # proceed
-            if block_delimiter == $1
-              end_tag
-              return
-            end
-
-            # fetch the tag from registered blocks
-            if tag = Template.tags[$1]
-              new_tag = tag.new_with_options($1, $2, tokens, @options || {})
-              @blank &&= new_tag.blank?
-              @nodelist << new_tag
-              @children << new_tag
-            else
-              # this tag is not registered with the system
-              # pass it to the current block for special handling or error reporting
-              unknown_tag($1, $2, tokens)
-            end
-          else
-            raise SyntaxError.new(options[:locale].t("errors.syntax.tag_termination", :token => token, :tag_end => TagEnd.inspect))
-          end
-        when IsVariable
-          new_var = create_variable(token)
-          @nodelist << new_var
-          @children << new_var
-          @blank = false
-        when ''
-          # pass
-        else
-          @nodelist << token
-          @blank &&= (token =~ /\A\s*\z/)
-        end
-      end
-
-      # 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
-      assert_missing_delimitation!
-    end
-
     # warnings of this block and all sub-tags
     def warnings
       all_warnings = []
       all_warnings.concat(@warnings) if @warnings
 
-      (@children || []).each do |node|
-        all_warnings.concat(node.warnings || [])
+      (nodelist || []).each do |node|
+        all_warnings.concat(node.warnings || []) if node.respond_to?(:warnings)
       end
 
       all_warnings
     end
 
-    def end_tag
-    end
-
     def unknown_tag(tag, params, tokens)
       case tag
       when 'else'
@@ -99,19 +43,20 @@ module Liquid
       @tag_name
     end
 
-    def create_variable(token)
-      token.scan(ContentOfVariable) do |content|
-        return Variable.new(content.first, @options)
-      end
-      raise SyntaxError.new(options[:locale].t("errors.syntax.variable_termination", :token => token, :tag_end => VariableEnd.inspect))
-    end
-
     def render(context)
       render_all(@nodelist, context)
     end
 
     protected
 
+    def unterminated_variable(token)
+      raise SyntaxError.new(options[:locale].t("errors.syntax.variable_termination", :token => token, :tag_end => VariableEnd.inspect))
+    end
+
+    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
@@ -150,7 +95,7 @@ module Liquid
         end
       end
 
-      output.join
+      StringSlice.join(output)
     end
   end
 end

lib/liquid/context.rb

@@ -29,7 +29,7 @@ module Liquid
     end
 
     def increment_used_resources(key, obj)
-      @resource_limits[key] += if obj.kind_of?(String) || obj.kind_of?(Array) || obj.kind_of?(Hash)
+      @resource_limits[key] += if obj.kind_of?(StringSlice) || obj.kind_of?(String) || obj.kind_of?(Array) || obj.kind_of?(Hash)
         obj.length
       else
         1
@@ -171,15 +171,15 @@ module Liquid
           LITERALS[key]
         else
           case key
-          when /^'(.*)'$/ # Single quoted strings
+          when /\A'(.*)'\z/ # Single quoted strings
             $1
-          when /^"(.*)"$/ # Double quoted strings
+          when /\A"(.*)"\z/ # Double quoted strings
             $1
-          when /^(-?\d+)$/ # Integer and floats
+          when /\A(-?\d+)\z/ # Integer and floats
             $1.to_i
-          when /^\((\S+)\.\.(\S+)\)$/ # Ranges
+          when /\A\((\S+)\.\.(\S+)\)\z/ # Ranges
             (resolve($1).to_i..resolve($2).to_i)
-          when /^(-?\d[\d\.]+)$/ # Floats
+          when /\A(-?\d[\d\.]+)\z/ # Floats
             $1.to_f
           else
             variable(key)
@@ -218,7 +218,7 @@ module Liquid
       #  assert_equal 'tobi', @context['hash["name"]']
       def variable(markup)
         parts = markup.scan(VariableParser)
-        square_bracketed = /^\[(.*)\]$/
+        square_bracketed = /\A\[(.*)\]\z/
 
         first_part = parts.shift
 

lib/liquid/document.rb

@@ -3,12 +3,12 @@ module Liquid
     # we don't need markup to open this block
     def initialize(tokens, options = {})
       @options = options
-      parse(tokens)
+      parse_body(tokens)
     end
 
     # There isn't a real delimiter
     def block_delimiter
-      []
+      nil
     end
 
     # Document blocks don't need to be terminated since they are not actually opened

lib/liquid/file_system.rb

@@ -57,7 +57,7 @@ module Liquid
     end
 
     def full_path(template_path)
-      raise FileSystemError, "Illegal template name '#{template_path}'" unless template_path =~ /^[^.\/][a-zA-Z0-9_\/]+$/
+      raise FileSystemError, "Illegal template name '#{template_path}'" unless template_path =~ /\A[^.\/][a-zA-Z0-9_\/]+\z/
 
       full_path = if template_path.include?('/')
         File.join(root, File.dirname(template_path), @pattern % File.basename(template_path))
@@ -65,7 +65,7 @@ module Liquid
         File.join(root, @pattern % template_path)
       end
 
-      raise FileSystemError, "Illegal template path '#{File.expand_path(full_path)}'" unless File.expand_path(full_path) =~ /^#{File.expand_path(root)}/
+      raise FileSystemError, "Illegal template path '#{File.expand_path(full_path)}'" unless File.expand_path(full_path) =~ /\A#{File.expand_path(root)}/
 
       full_path
     end

lib/liquid/htmltags.rb

@@ -55,7 +55,7 @@ module Liquid
 
           col += 1
 
-          result << "<td class=\"col#{col}\">" << render_all(@nodelist, context) << '</td>'
+          result << "<td class=\"col#{col}\">" << super << '</td>'
 
           if col == cols and (index != length - 1)
             col  = 0

lib/liquid/standardfilters.rb

@@ -190,7 +190,7 @@ module Liquid
         return input.to_s
       end
 
-      if ((input.is_a?(String) && !/^\d+$/.match(input.to_s).nil?) || input.is_a?(Integer)) && input.to_i > 0
+      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
 
@@ -281,7 +281,7 @@ module Liquid
       when Numeric
         obj
       when String
-        (obj.strip =~ /^\d+\.\d+$/) ? BigDecimal.new(obj) : obj.to_i
+        (obj.strip =~ /\A\d+\.\d+\z/) ? BigDecimal.new(obj) : obj.to_i
       else
         0
       end

lib/liquid/tag.rb

@@ -16,10 +16,6 @@ module Liquid
       @tag_name   = tag_name
       @markup     = markup
       @options    ||= {} # needs || because might be set before initialize
-      parse(tokens)
-    end
-
-    def parse(tokens)
     end
 
     def name

lib/liquid/tags/cycle.rb

@@ -12,8 +12,8 @@ module Liquid
   #    <div class="green"> Item five</div>
   #
   class Cycle < Tag
-    SimpleSyntax = /^#{QuotedFragment}+/o
-    NamedSyntax  = /^(#{QuotedFragment})\s*\:\s*(.*)/o
+    SimpleSyntax = /\A#{QuotedFragment}+/o
+    NamedSyntax  = /\A(#{QuotedFragment})\s*\:\s*(.*)/o
 
     def initialize(tag_name, markup, tokens)
       case markup

lib/liquid/tags/ifchanged.rb

@@ -4,7 +4,7 @@ module Liquid
     def render(context)
       context.stack do
 
-        output = render_all(@nodelist, context)
+        output = super
 
         if output != context.registers[:ifchanged]
           context.registers[:ifchanged] = output

lib/liquid/tags/include.rb

@@ -35,9 +35,6 @@ module Liquid
       super
     end
 
-    def parse(tokens)
-    end
-
     def blank?
       false
     end

lib/liquid/tags/raw.rb

@@ -1,17 +1,14 @@
 module Liquid
   class Raw < Block
-    FullTokenPossiblyInvalid = /^(.*)#{TagStart}\s*(\w+)\s*(.*)?#{TagEnd}$/o
+    FullTokenPossiblyInvalid = /\A(.*)#{TagStart}\s*(\w+)\s*(.*)?#{TagEnd}\z/o
 
-    def parse(tokens)
+    def parse_body(tokens)
       @nodelist ||= []
       @nodelist.clear
       while token = tokens.shift
         if token =~ FullTokenPossiblyInvalid
           @nodelist << $1 if $1 != ""
-          if block_delimiter == $2
-            end_tag
-            return
-          end
+          return if block_delimiter == $2
         end
         @nodelist << token if not token.empty?
       end

lib/liquid/template.rb

@@ -162,16 +162,9 @@ module Liquid
 
     private
 
-    # Uses the <tt>Liquid::TemplateParser</tt> regexp to tokenize the passed source
     def tokenize(source)
       source = source.source if source.respond_to?(:source)
-      return [] if source.to_s.empty?
-      tokens = source.split(TemplateParser)
-
-      # removes the rogue empty element at the beginning of the array
-      tokens.shift if tokens[0] and tokens[0].empty?
-
-      tokens
+      Tokenizer.new(source.to_s)
     end
 
   end

lib/liquid/variable.rb

@@ -12,7 +12,7 @@ module Liquid
   #
   class Variable
     FilterParser = /(?:#{FilterSeparator}|(?:\s*(?:#{QuotedFragment}|#{ArgumentSeparator})\s*)+)/o
-    EasyParse = /^ *(\w+(?:\.\w+)*) *$/
+    EasyParse = /\A *(\w+(?:\.\w+)*) *\z/
     attr_accessor :filters, :name, :warnings
 
     def initialize(markup, options = {})

liquid.gemspec

@@ -18,9 +18,15 @@ Gem::Specification.new do |s|
   s.required_rubygems_version = ">= 1.3.7"
 
   s.test_files  = Dir.glob("{test}/**/*")
-  s.files       = Dir.glob("{lib}/**/*") + %w(MIT-LICENSE README.md)
+  s.files       = Dir.glob("{lib,ext}/**/*") + %w(MIT-LICENSE README.md)
+  s.extensions  = ['ext/liquid/extconf.rb']
 
   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'
 end

performance/shopify/shop_filter.rb

@@ -54,7 +54,7 @@ module ShopFilter
 
   def product_img_url(url, style = 'small')
 
-    unless url =~ /^products\/([\w\-\_]+)\.(\w{2,4})/
+    unless url =~ /\Aproducts\/([\w\-\_]+)\.(\w{2,4})/
       raise ArgumentError, 'filter "size" can only be called on product images'
     end
 

performance/stackprof.rb

@@ -0,0 +1,15 @@
+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

test/liquid/block_test.rb

@@ -12,34 +12,34 @@ class BlockTest < Test::Unit::TestCase
     template = Liquid::Template.parse("{{funk}}  ")
     assert_equal 2, template.root.nodelist.size
     assert_equal Variable, template.root.nodelist[0].class
-    assert_equal String, template.root.nodelist[1].class
+    assert_equal StringSlice, template.root.nodelist[1].class
   end
 
   def test_variable_end
     template = Liquid::Template.parse("  {{funk}}")
     assert_equal 2, template.root.nodelist.size
-    assert_equal String, template.root.nodelist[0].class
+    assert_equal StringSlice, template.root.nodelist[0].class
     assert_equal Variable, template.root.nodelist[1].class
   end
 
   def test_variable_middle
     template = Liquid::Template.parse("  {{funk}}  ")
     assert_equal 3, template.root.nodelist.size
-    assert_equal String, template.root.nodelist[0].class
+    assert_equal StringSlice, template.root.nodelist[0].class
     assert_equal Variable, template.root.nodelist[1].class
-    assert_equal String, template.root.nodelist[2].class
+    assert_equal StringSlice, template.root.nodelist[2].class
   end
 
   def test_variable_many_embedded_fragments
     template = Liquid::Template.parse("  {{funk}} {{so}} {{brother}} ")
     assert_equal 7, template.root.nodelist.size
-    assert_equal [String, Variable, String, Variable, String, Variable, String],
+    assert_equal [StringSlice, Variable, StringSlice, Variable, StringSlice, Variable, StringSlice],
                  block_types(template.root.nodelist)
   end
 
   def test_with_block
     template = Liquid::Template.parse("  {% comment %} {% endcomment %} ")
-    assert_equal [String, Comment, String], block_types(template.root.nodelist)
+    assert_equal [StringSlice, Comment, StringSlice], block_types(template.root.nodelist)
     assert_equal 3, template.root.nodelist.size
   end
 

test/liquid/parsing_quirks_test.rb

@@ -8,7 +8,7 @@ class ParsingQuirksTest < Test::Unit::TestCase
     template = Template.parse(text)
 
     assert_equal text, template.render
-    assert_equal [String], template.root.nodelist.collect {|i| i.class}
+    assert_equal [StringSlice], template.root.nodelist.collect {|i| i.class}
   end
 
   def test_raise_on_single_close_bracet

test/liquid/string_slice_test.rb

@@ -0,0 +1,34 @@
+require 'test_helper'
+
+class StringSliceTest < Test::Unit::TestCase
+  def test_new_from_string
+    assert_equal 'slice', Liquid::StringSlice.new("slice and dice", 0, 5).to_str
+    assert_equal 'and', Liquid::StringSlice.new("slice and dice", 6, 3).to_str
+    assert_equal 'dice', Liquid::StringSlice.new("slice and dice", 10, 4).to_str
+    assert_equal 'slice and dice', Liquid::StringSlice.new("slice and dice", 0, 14).to_str
+  end
+
+  def test_new_from_slice
+    slice1 = Liquid::StringSlice.new("slice and dice", 0, 14)
+    slice2 = Liquid::StringSlice.new(slice1, 6, 8)
+    slice3 = Liquid::StringSlice.new(slice2, 0, 3)
+    assert_equal "slice and dice", slice1.to_str
+    assert_equal "and dice", slice2.to_str
+    assert_equal "and", slice3.to_str
+  end
+
+  def test_slice
+    slice = Liquid::StringSlice.new("slice and dice", 2, 10)
+    assert_equal "and", slice.slice(4, 3).to_str
+  end
+
+  def test_length
+    slice = Liquid::StringSlice.new("slice and dice", 6, 3)
+    assert_equal 3, slice.length
+    assert_equal 3, slice.size
+  end
+
+  def test_equal
+    assert_equal 'and', Liquid::StringSlice.new("slice and dice", 6, 3)
+  end
+end

test/liquid/template_test.rb

@@ -25,26 +25,6 @@ end
 class TemplateTest < Test::Unit::TestCase
   include Liquid
 
-  def test_tokenize_strings
-    assert_equal [' '], Template.new.send(:tokenize, ' ')
-    assert_equal ['hello world'], Template.new.send(:tokenize, 'hello world')
-  end
-
-  def test_tokenize_variables
-    assert_equal ['{{funk}}'], Template.new.send(:tokenize, '{{funk}}')
-    assert_equal [' ', '{{funk}}', ' '], Template.new.send(:tokenize, ' {{funk}} ')
-    assert_equal [' ', '{{funk}}', ' ', '{{so}}', ' ', '{{brother}}', ' '], Template.new.send(:tokenize, ' {{funk}} {{so}} {{brother}} ')
-    assert_equal [' ', '{{  funk  }}', ' '], Template.new.send(:tokenize, ' {{  funk  }} ')
-  end
-
-  def test_tokenize_blocks
-    assert_equal ['{%comment%}'], Template.new.send(:tokenize, '{%comment%}')
-    assert_equal [' ', '{%comment%}', ' '], Template.new.send(:tokenize, ' {%comment%} ')
-
-    assert_equal [' ', '{%comment%}', ' ', '{%endcomment%}', ' '], Template.new.send(:tokenize, ' {%comment%} {%endcomment%} ')
-    assert_equal ['  ', '{% comment %}', ' ', '{% endcomment %}', ' '], Template.new.send(:tokenize, "  {% comment %} {% endcomment %} ")
-  end
-
   def test_instance_assigns_persist_on_same_template_object_between_parses
     t = Template.new
     assert_equal 'from instance assigns', t.parse("{% assign foo = 'from instance assigns' %}{{ foo }}").render

test/liquid/tokenizer_test.rb

@@ -0,0 +1,64 @@
+require 'test_helper'
+
+class TokenizerTest < Test::Unit::TestCase
+  def test_tokenize_strings
+    assert_equal [' '], tokenize(' ')
+    assert_equal ['hello world'], tokenize('hello world')
+  end
+
+  def test_tokenize_variables
+    assert_equal ['{{funk}}'], tokenize('{{funk}}')
+    assert_equal [' ', '{{funk}}', ' '], tokenize(' {{funk}} ')
+    assert_equal [' ', '{{funk}}', ' ', '{{so}}', ' ', '{{brother}}', ' '], tokenize(' {{funk}} {{so}} {{brother}} ')
+    assert_equal [' ', '{{  funk  }}', ' '], tokenize(' {{  funk  }} ')
+  end
+
+  def test_tokenize_blocks
+    assert_equal ['{%comment%}'], tokenize('{%comment%}')
+    assert_equal [' ', '{%comment%}', ' '], tokenize(' {%comment%} ')
+
+    assert_equal [' ', '{%comment%}', ' ', '{%endcomment%}', ' '], tokenize(' {%comment%} {%endcomment%} ')
+    assert_equal ['  ', '{% comment %}', ' ', '{% endcomment %}', ' '], tokenize("  {% comment %} {% endcomment %} ")
+  end
+
+  def test_tokenize_incomplete_end
+    assert_tokens 'before{{ incomplete }after', ['before', '{{ incomplete }', 'after']
+    assert_tokens 'before{% incomplete %after', ['before', '{%', ' incomplete %after']
+  end
+
+  def test_tokenize_no_end
+    assert_tokens 'before{{ unterminated ', ['before', '{{', ' unterminated ']
+    assert_tokens 'before{% unterminated ', ['before', '{%', ' unterminated ']
+  end
+
+  private
+
+  def assert_tokens(source, expected)
+    assert_equal expected, tokenize(source)
+    assert_equal expected, old_tokenize(source)
+  end
+
+  def tokenize(source)
+    tokenizer = Liquid::Tokenizer.new(source)
+    tokens = []
+    while token = tokenizer.next
+      tokens << token
+    end
+    tokens
+  end
+
+  AnyStartingTag        = /\{\{|\{\%/
+  VariableIncompleteEnd = /\}\}?/
+  PartialTemplateParser = /#{Liquid::TagStart}.*?#{Liquid::TagEnd}|#{Liquid::VariableStart}.*?#{VariableIncompleteEnd}/o
+  TemplateParser        = /(#{PartialTemplateParser}|#{AnyStartingTag})/o
+
+  def old_tokenize(source)
+    return [] if source.to_s.empty?
+    tokens = source.split(TemplateParser)
+
+    # removes the rogue empty element at the beginning of the array
+    tokens.shift if tokens[0] and tokens[0].empty?
+
+    tokens
+  end
+end