Resolve literals faster.

lib/liquid/context.rb

@@ -111,6 +111,14 @@ module Liquid
     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
@@ -120,17 +128,10 @@ module Liquid
       # Example:
       #   products == empty #=> products.empty?
       def resolve(key)
+        if LITERALS.key?(key)
+          LITERALS[key]
+        else
           case key
-        when nil, 'nil', 'null', ''
-          nil
-        when 'true'
-          true
-        when 'false'
-          false
-        when 'blank'
-          :blank?
-        when 'empty'
-          :empty?
           when /^'(.*)'$/ # Single quoted strings
             $1.to_s
           when /^"(.*)"$/ # Double quoted strings
@@ -145,6 +146,7 @@ module Liquid
             variable(key)
           end
         end
+      end
 
       # Fetches an object starting at the local scope and then moving up the hierachy
       def find_variable(key)