Merge pull request #384 from Shopify/optimize_block_parsing

Optimize block parsing -- don't recreate delimiter, use strings instead of regex

lib/liquid/block.rb

@@ -1,9 +1,14 @@
 module Liquid
   class Block < Tag
-    IsTag             = /\A#{TagStart}/o
-    IsVariable        = /\A#{VariableStart}/o
     FullToken         = /\A#{TagStart}\s*(\w+)\s*(.*)?#{TagEnd}\z/om
     ContentOfVariable = /\A#{VariableStart}(.*)#{VariableEnd}\z/om
+    TAGSTART = "{%".freeze
+    VARSTART = "{{".freeze
+
+    def initialize(tag_name, markup, options)
+      super
+      @block_delimiter = "end#{tag_name}"
+    end 
 
     def blank?
       @blank || false
@@ -18,13 +23,14 @@ module Liquid
       @children = []
 
       while token = tokens.shift
-        case token
-        when IsTag
+        unless token.empty?
+          case
+          when token.start_with?(TAGSTART)
             if token =~ FullToken
 
               # if we found the proper block delimiter just end parsing here and let the outer block
               # proceed
-            if block_delimiter == $1
+              if @block_delimiter == $1
                 end_tag
                 return
               end
@@ -43,18 +49,17 @@ module Liquid
             else
               raise SyntaxError.new(options[:locale].t("errors.syntax.tag_termination".freeze, :token => token, :tag_end => TagEnd.inspect))
             end
-        when IsVariable
+          when token.start_with?(VARSTART) 
             new_var = create_variable(token)
             @nodelist << new_var
             @children << new_var
             @blank = false
-        when ''.freeze
-          # pass
           else
             @nodelist << token
             @blank &&= (token =~ /\A\s*\z/)
           end
         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
@@ -85,16 +90,12 @@ module Liquid
       when 'end'.freeze
         raise SyntaxError.new(options[:locale].t("errors.syntax.invalid_delimiter".freeze,
                                                  :block_name => block_name,
-                                                 :block_delimiter => block_delimiter))
+                                                 :block_delimiter => @block_delimiter))
       else
         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

lib/liquid/tags/raw.rb

@@ -8,7 +8,7 @@ module Liquid
       while token = tokens.shift
         if token =~ FullTokenPossiblyInvalid
           @nodelist << $1 if $1 != "".freeze
-          if block_delimiter == $2
+          if @block_delimiter == $2
             end_tag
             return
           end