if blocks work with filtered variables

lib/liquid/context.rb

@@ -133,6 +133,9 @@ module Liquid
         :blank?
       when 'empty'
         :empty?
+      # filtered variables
+      when SpacelessFilter
+        filtered_variable(key)
       # Single quoted strings
       when /^'(.*)'$/
         $1.to_s
@@ -221,5 +224,9 @@ module Liquid
 
       object
     end
+    
+    def filtered_variable(markup)
+      Variable.new(markup).render(self)
+    end
   end
 end

lib/liquid/tags/if.rb

@@ -13,7 +13,7 @@ module Liquid
   #
   class If < Block
     SyntaxHelp = "Syntax Error in tag 'if' - Valid syntax: if [expression]"
-    Syntax = /(#{QuotedFragment})\s*([=!<>a-z_]+)?\s*(#{QuotedFragment})?/
+    Syntax = /(#{Expression})\s*([=!<>a-z_]+)?\s*(#{Expression})?/
     
     def initialize(tag_name, markup, tokens)    
     

lib/liquid/variable.rb

@@ -19,8 +19,8 @@ module Liquid
       @filters = []
       if match = markup.match(/\s*(#{QuotedFragment})/)
         @name = match[1]
-        if markup.match(/#{FilterSperator}\s*(.*)/)
-          filters = Regexp.last_match(1).split(/#{FilterSperator}/)
+        if markup.match(/#{FilterSeparator}\s*(.*)/)
+          filters = Regexp.last_match(1).split(/#{FilterSeparator}/)
         
           filters.each do |f|    
             if matches = f.match(/\s*(\w+)/)