Add support for maps in functions

Author: Ruben Swieringa

lib/sassc/native/native_functions_api.rb

@@ -24,6 +24,24 @@ module Native
     # ADDAPI union Sass_Value* ADDCALL sass_make_color   (double r, double g, double b, double a);
     attach_function :sass_make_color, [:double, :double, :double, :double], :sass_value_ptr
 
+    # ADDAPI union Sass_Value* ADDCALL sass_make_map     (size_t len);
+    attach_function :sass_make_map, [:size_t], :sass_value_ptr
+
+    # ADDAPI void ADDCALL sass_map_set_key (union Sass_Value* v, size_t i, union Sass_Value*);
+    attach_function :sass_map_set_key, [:sass_value_ptr, :size_t, :sass_value_ptr], :void
+
+    # ADDAPI union Sass_Value* ADDCALL sass_map_get_key (const union Sass_Value* v, size_t i);
+    attach_function :sass_map_get_key, [:sass_value_ptr, :size_t], :sass_value_ptr
+
+    # ADDAPI void ADDCALL sass_map_set_value (union Sass_Value* v, size_t i, union Sass_Value*);
+    attach_function :sass_map_set_value, [:sass_value_ptr, :size_t, :sass_value_ptr], :void
+
+    # ADDAPI union Sass_Value* ADDCALL sass_map_get_value (const union Sass_Value* v, size_t i);
+    attach_function :sass_map_get_value, [:sass_value_ptr, :size_t], :sass_value_ptr
+
+    # ADDAPI size_t ADDCALL sass_map_get_length (const union Sass_Value* v);
+    attach_function :sass_map_get_length, [:sass_value_ptr], :size_t
+
     # ADDAPI union Sass_Value* ADDCALL sass_make_error   (const char* msg);
     attach_function :sass_make_error, [:string], :sass_value_ptr
 

lib/sassc/script/value_conversion.rb

@@ -23,6 +23,18 @@ def self.from_native(native_value, options)
           argument = Script::Color.new([red, green, blue, alpha])
           argument.options = options
 
+          argument
+        when :sass_map
+          values = {}
+          length = Native::map_get_length native_value
+
+          (0..length-1).each do |index|
+            key = Native::map_get_key(native_value, index)
+            value = Native::map_get_value(native_value, index)
+            values[from_native(key, options)] = from_native(value, options)
+          end
+
+          argument = Sass::Script::Value::Map.new values
           argument
         else
           raise UnsupportedValue.new("Sass argument of type #{value_tag} unsupported")
@@ -37,6 +49,8 @@ def self.to_native(value)
           Color.new(value).to_native
         when "Number"
           Number.new(value).to_native
+        when "Map"
+          Map.new(value).to_native
         else
           raise UnsupportedValue.new("Sass return type #{value_name} unsupported")
         end
@@ -49,3 +63,4 @@ def self.to_native(value)
 require_relative "value_conversion/string"
 require_relative "value_conversion/number"
 require_relative "value_conversion/color"
+require_relative "value_conversion/map"

lib/sassc/script/value_conversion/map.rb

@@ -0,0 +1,19 @@
+module SassC
+  module Script
+    module ValueConversion
+      class Map < Base
+        def to_native
+          hash = @value.to_h
+          native_map = Native::make_map( hash.size )
+          hash.each_with_index do |(key, value), index|
+            key   = ValueConversion.to_native key
+            value = ValueConversion.to_native value
+            Native::map_set_key(   native_map, index, key )
+            Native::map_set_value( native_map, index, value )
+          end
+          return native_map
+        end
+      end
+    end
+  end
+end

test/functions_test.rb

@@ -133,6 +133,23 @@ def test_function_that_returns_a_sass_value
       CSS
     end
 
+    def test_function_that_returns_a_sass_map
+      assert_sass <<-SCSS, <<-CSS
+        $my-map: returns-sass-map();
+        div { background: map-get( $my-map, color ); }
+      SCSS
+        div { background: black; }
+      CSS
+    end
+
+    def test_function_that_takes_a_sass_map
+      assert_sass <<-SCSS, <<-CSS
+        div { background-color: map-get( returns-arg(( dark: black, light: white )), dark ); }
+      SCSS
+        div { background-color: black; }
+      CSS
+    end
+
     private
 
     def assert_sass(sass, expected_css)
@@ -190,6 +207,15 @@ def returns_sass_value
         return Sass::Script::Value::Color.new(red: 0, green: 0, blue: 0)
       end
 
+      def returns_sass_map
+        key = Script::String.new("color", "string")
+        value = Sass::Script::Value::Color.new(red: 0, green: 0, blue: 0)
+        values = {}
+        values[key] = value
+        map = Sass::Script::Value::Map.new values
+        return map
+      end
+
       module Compass
         def stylesheet_path(path)
           Script::String.new("/css/#{path.value}", :identifier)