Implemented the hue, saturation, and lightness built-ins.

context.cpp

@@ -111,6 +111,9 @@ namespace Sass {
     // HSL Functions
     register_function(hsla_sig, hsla);
     register_function(hsl_sig, hsl);
+    register_function(hue_sig, hue);
+    register_function(saturation_sig, saturation);
+    register_function(lightness_sig, lightness);
     register_function(adjust_hue_sig, adjust_hue);
     register_function(adjust_color_sig, adjust_color);
     register_function(change_color_sig, change_color);

functions.cpp

@@ -44,6 +44,19 @@ namespace Sass {
 
   namespace Functions {
 
+    extern const char true_str[]  = "true";
+    extern const char false_str[] = "false";
+
+    extern const char empty_str[]   = "";
+    extern const char percent_str[] = "%";
+    extern const char deg_str[]     = "deg";
+
+    extern const char number_name[] = "number";
+    extern const char string_name[] = "string";
+    extern const char bool_name[]   = "bool";
+    extern const char color_name[]  = "color";
+    extern const char list_name[]   = "list";
+    
     static void throw_eval_error(string message, string path, size_t line)
     {
       if (!path.empty() && Prelexer::string_constant(path.c_str()))
@@ -238,6 +251,36 @@ namespace Sass {
       return color;
     }
 
+    extern Signature hue_sig = "hue($color)";
+    Node hue(const Node parameter_names, Environment& bindings, Node_Factory& new_Node) {
+      Node rgb_color(bindings[parameter_names[0].token()]);
+      Node hsl_color(rgb_to_hsl(rgb_color[0].numeric_value(),
+                                rgb_color[1].numeric_value(),
+                                rgb_color[2].numeric_value(),
+                                new_Node));
+      return new_Node("", 0, hsl_color[0].numeric_value(), Token::make(deg_str));
+    }
+
+    extern Signature saturation_sig = "saturation($color)";
+    Node saturation(const Node parameter_names, Environment& bindings, Node_Factory& new_Node) {
+      Node rgb_color(bindings[parameter_names[0].token()]);
+      Node hsl_color(rgb_to_hsl(rgb_color[0].numeric_value(),
+                                rgb_color[1].numeric_value(),
+                                rgb_color[2].numeric_value(),
+                                new_Node));
+      return new_Node("", 0, hsl_color[1].numeric_value(), Token::make(percent_str));
+    }
+
+    extern Signature lightness_sig = "lightness($color)";
+    Node lightness(const Node parameter_names, Environment& bindings, Node_Factory& new_Node) {
+      Node rgb_color(bindings[parameter_names[0].token()]);
+      Node hsl_color(rgb_to_hsl(rgb_color[0].numeric_value(),
+                                rgb_color[1].numeric_value(),
+                                rgb_color[2].numeric_value(),
+                                new_Node));
+      return new_Node("", 0, hsl_color[2].numeric_value(), Token::make(percent_str));
+    }
+
     extern Signature adjust_hue_sig = "adjust-hue($color, $degrees)";
     Node adjust_hue(const Node parameter_names, Environment& bindings, Node_Factory& new_Node) {
       Node rgb_col(bindings[parameter_names[0].token()]);
@@ -714,12 +757,6 @@ namespace Sass {
 
     // Introspection Functions /////////////////////////////////////////////
     
-    extern const char number_name[] = "number";
-    extern const char string_name[] = "string";
-    extern const char bool_name[]   = "bool";
-    extern const char color_name[]  = "color";
-    extern const char list_name[]   = "list";
-    
     extern Signature type_of_sig = "type-of($value)";
     Node type_of(const Node parameter_names, Environment& bindings, Node_Factory& new_Node) {
       Node val(bindings[parameter_names[0].token()]);
@@ -754,10 +791,7 @@ namespace Sass {
       type.is_unquoted() = true;
       return type;
     }
-    
-    extern const char empty_str[] = "";
-    extern const char percent_str[] = "%";
-    
+
     extern Signature unit_sig = "unit($number)";
     Node unit(const Node parameter_names, Environment& bindings, Node_Factory& new_Node) {
       Node val(bindings[parameter_names[0].token()]);
@@ -780,9 +814,6 @@ namespace Sass {
       return Node();
     }
 
-    extern const char true_str[]  = "true";
-    extern const char false_str[] = "false";
-
     extern Signature unitless_sig = "unitless($number)";
     Node unitless(const Node parameter_names, Environment& bindings, Node_Factory& new_Node) {
       Node val(bindings[parameter_names[0].token()]);

functions.hpp

@@ -92,6 +92,15 @@ namespace Sass {
     extern Signature hsl_sig;
     Node hsl(const Node, Environment&, Node_Factory&);
 
+    extern Signature hue_sig;
+    Node hue(const Node, Environment&, Node_Factory&);
+
+    extern Signature saturation_sig;
+    Node saturation(const Node, Environment&, Node_Factory&);
+
+    extern Signature lightness_sig;
+    Node lightness(const Node, Environment&, Node_Factory&);
+
     extern Signature adjust_hue_sig;
     Node adjust_hue(const Node, Environment&, Node_Factory&);