zip($list1, $list2, ...) returns a new combined list of lists.

doc-src/SASS_CHANGELOG.md

@@ -7,6 +7,10 @@
 
 * Fix some issues that were breaking Sass when running within Rubinius.
 * Fix some issues that were affecting Rails 3.1 integration.
+* New function `zip` allows several lists to be combined into one
+  list of lists. For example:
+  `zip(1px 1px 3px, solid dashed solid, red green blue)` becomes
+  `1px solid red, 1px dashed green, 3px solid blue`
 * New function `index` returns the list index of a value
   within a list. For example: `index(1px solid red, solid)`
   returns `2`. When the value is not found `false` is returned.

lib/sass/script/functions.rb

@@ -1299,6 +1299,32 @@ def append(list, val, separator = Sass::Script::String.new("auto"))
     declare :append, [:list, :val]
     declare :append, [:list, :val, :separator]
 
+    # Combines several lists into a single comma separated list
+    # space separated lists.
+    #
+    # The length of the resulting list is the length of the
+    # shortest list.
+    #
+    # @example
+    #   zip(1px 1px 3px, solid dashed solid, red green blue)
+    #   => 1px solid red, 1px dashed green, 3px solid blue
+    def zip(*lists)
+      length = nil
+      values = []
+      lists.each do |list|
+        assert_type list, :List
+        values << list.value.dup
+        length = length.nil? ? list.value.length : [length, list.value.length].min
+      end
+      values.each do |value|
+        value.slice!(length)
+      end
+      new_list_value = values.first.zip(*values[1..-1])
+      List.new(new_list_value.map{|list| List.new(list, :space)}, :comma)
+    end
+    declare :zip, [], :var_args => true
+
+
     # Returns the position of the given value within the given
     # list. If not found, returns false.
     #

test/sass/functions_test.rb

@@ -965,6 +965,11 @@ def test_append
     assert_error_message("Separator name must be space, comma, or auto for `append'", "append(1, 2, baboon)")
   end
 
+  def test_zip
+    assert_equal("1 3 5, 2 4 6", evaluate("zip(1 2, 3 4, 5 6)"))
+    assert_equal("1 4 7, 2 5 8", evaluate("zip(1 2 3, 4 5 6, 7 8)"))
+  end
+
   def test_index
     assert_equal("1", evaluate("index(1px solid blue, 1px)"))
     assert_equal("2", evaluate("index(1px solid blue, solid)"))