Implemented "type-of".

basic.scss

@@ -63,4 +63,8 @@ div {
   f: join((1,2,3), ());
   g: join((), (1,2,3));
   h: hello join((),(), auto);
+  
+  a: type-of(false);
+  b: type-of("true");
+  c: type-of(a b c);
 }

context.cpp

@@ -62,6 +62,11 @@ namespace Sass {
     register_function(nth_descriptor, nth);
     register_function(join_2_descriptor, join_2);
     register_function(join_3_descriptor, join_3);
+    // Introspection Functions
+    register_function(type_of_descriptor, type_of);
+    // register_function(unit_descriptor, unit);
+    // register_function(unitless_descriptor, unitless);
+    // register_function(comparable_descriptor, comparable);
   }
   
 }
\ No newline at end of file

functions.cpp

@@ -220,6 +220,7 @@ namespace Sass {
     }
     
     // List Functions //////////////////////////////////////////////////////
+
     Function_Descriptor length_descriptor =
     { "length", "$list", 0 };
     Node length(const vector<Token>& parameters, map<Token, Node>& bindings) {
@@ -291,13 +292,52 @@ namespace Sass {
       return join_impl(parameters, bindings, true);
     }
     
-    
-    
-    
-    
-    
-    
-    
+    // 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";
+    
+    Function_Descriptor type_of_descriptor =
+    { "type-of", "$value", 0 };
+    Node type_of(const vector<Token>& parameters, map<Token, Node>& bindings) {
+      Node val(bindings[parameters[0]]);
+      Node type(Node::string_constant, val.line_number, Token::make());
+      type.unquoted = true;
+      switch (val.type)
+      {
+        case Node::number:
+        case Node::numeric_dimension:
+        case Node::numeric_percentage:
+          type.content.token = Token::make(number_name);
+          break;
+        case Node::identifier: {
+          string text(val.content.token.to_string());
+          if (text == "true" || text == "false") {
+            type.content.token = Token::make(bool_name);
+          }
+          else {
+            type.content.token = Token::make(string_name);
+          }
+        } break;
+        case Node::string_constant:
+          type.content.token = Token::make(string_name);
+          break;
+        case Node::numeric_color:
+          type.content.token = Token::make(color_name);
+          break;
+        case Node::comma_list:
+        case Node::space_list:
+        case Node::nil:
+          type.content.token = Token::make(list_name);
+          break;
+        default:
+          type.content.token = Token::make(string_name);
+      }
+      return type;
+    }
     
     
     

functions.hpp

@@ -128,6 +128,20 @@ namespace Sass {
     extern Function_Descriptor join_3_descriptor;    
     Node join_3(const vector<Token>& parameters, map<Token, Node>& bindings);
     
+    // Introspection Functions /////////////////////////////////////////////
+    
+    extern Function_Descriptor type_of_descriptor;
+    Node type_of(const vector<Token>& parameters, map<Token, Node>& bindings);
+
+    // extern Function_Descriptor unit_descriptor;
+    // Node unit(const vector<Token>& parameters, map<Token, Node>& bindings);
+    // 
+    // extern Function_Descriptor unitless_descriptor;    
+    // Node unitless(const vector<Token>& parameters, map<Token, Node>& bindings);
+    // 
+    // extern Function_Descriptor comparable_descriptor;    
+    // Node comparable(const vector<Token>& parameters, map<Token, Node>& bindings);
+
   }
   
 }