Merge pull request #240 from Shopify/remove_flatten

remove .flatten on standard filters

lib/liquid/standardfilters.rb

@@ -92,16 +92,16 @@ module Liquid
 
     # Join elements of the array with certain character between them
     def join(input, glue = ' '.freeze)
-      [input].flatten.join(glue)
+      InputIterator.new(input).join(glue)
     end
 
     # Sort elements of the array
     # provide optional property with which to sort an array of hashes or drops
     def sort(input, property = nil)
-      ary = flatten_if_necessary(input)
+      ary = InputIterator.new(input)
       if property.nil?
         ary.sort
-      elsif ary.first.respond_to?('[]'.freeze) and !ary.first[property].nil?
+      elsif ary.first.respond_to?('[]'.freeze) && !ary.first[property].nil?
         ary.sort {|a,b| a[property] <=> b[property] }
       elsif ary.first.respond_to?(property)
         ary.sort {|a,b| a.send(property) <=> b.send(property) }
@@ -110,13 +110,13 @@ module Liquid
 
     # Reverse the elements of an array
     def reverse(input)
-      ary = [input].flatten
+      ary = InputIterator.new(input)
       ary.reverse
     end
 
     # map/collect on a given property
     def map(input, property)
-      flatten_if_necessary(input).map do |e|
+      InputIterator.new(input).map do |e|
         e = e.call if e.is_a?(Proc)
 
         if property == "to_liquid".freeze
@@ -265,17 +265,6 @@ module Liquid
 
     private
 
-    def flatten_if_necessary(input)
-      ary = if input.is_a?(Array)
-        input.flatten
-      elsif input.is_a?(Enumerable) && !input.is_a?(Hash)
-        input
-      else
-        [input].flatten
-      end
-      ary.map{ |e| e.respond_to?(:to_liquid) ? e.to_liquid : e }
-    end
-
     def to_number(obj)
       case obj
       when Float
@@ -310,6 +299,36 @@ module Liquid
       result = to_number(input).send(operation, to_number(operand))
       result.is_a?(BigDecimal) ? result.to_f : result
     end
+
+    class InputIterator
+      include Enumerable
+
+      def initialize(input)
+        @input = if input.is_a?(Array)
+          input.flatten
+        elsif input.is_a?(Hash)
+          [input]
+        elsif input.is_a?(Enumerable)
+          input
+        else
+          Array(input)
+        end
+      end
+
+      def join(glue)
+        to_a.join(glue)
+      end
+
+      def reverse
+        reverse_each.to_a
+      end
+
+      def each
+        @input.each do |e|
+          yield(e.respond_to?(:to_liquid) ? e.to_liquid : e)
+        end
+      end
+    end
   end
 
   Template.register_filter(StandardFilters)