deferred mixin calls

lesscpy/plib/mixin.py

@@ -26,24 +26,10 @@ class Mixin(Node):
                       if hasattr(v, 'parse') else v
                       for v in copy.deepcopy(self.args)]
             args = args if type(args) is list else [args]
-            vars = []
-            for arg, var in itertools.zip_longest([a for a in args if a != ','], parsed):
-                if arg is None and utility.is_variable(var):
-                    raise SyntaxError('Missing argument to mixin')
-                if arg == var and utility.is_variable(arg):
-                    continue
-                elif utility.is_variable(arg):
-                    tmp = scope.variables(arg)
-                    if not tmp: continue
-                    var = Variable([var, None, tmp.name]).parse(scope)
-                elif type(var) is Variable:
-                    if arg: var.value = arg
-                elif utility.is_variable(var):
-                    var = Variable([var, None, arg]).parse(scope)
-                else: continue
-                vars.append(var)
+            vars = [self._parse_arg(var, arg, scope) 
+                    for arg, var in itertools.zip_longest([a for a in args if a != ','], parsed)]
             for var in vars:
-                scope.add_variable(var)
+                if var: scope.add_variable(var)
             if not arguments:
                 arguments = [v.value for v in vars]
         if arguments:
@@ -53,6 +39,32 @@ class Mixin(Node):
         scope.add_variable(Variable(['@arguments', 
                                      None, 
                                      arguments]).parse(scope))
+        
+    def _parse_arg(self, var, arg, scope):
+        """
+        """
+        if type(var) is Variable:
+            # kwarg
+            if arg:
+                if utility.is_variable(arg):
+                    tmp = scope.variables(arg)
+                    if not tmp: return None
+                    var.value = tmp.value
+                else:
+                    var.value = arg
+        else:
+            #arg
+            if utility.is_variable(var):
+                if arg is None:
+                    raise SyntaxError('Missing argument to mixin')
+                elif utility.is_variable(arg):
+                    tmp = scope.variables(arg)
+                    if not tmp: return None
+                    var = Variable([var, None, tmp.value]).parse(scope)
+                else:
+                    var = Variable([var, None, arg]).parse(scope)
+        return var
+#        if var: collect.append(var)
     
     def call(self, scope, args=None):
         """

lesscpy/test/css/mixin-args-nested.css

@@ -67,4 +67,7 @@
 }
 .font {
 	font-family: Georgia, "Times New Roman", Times, serif;
-}
+}
+.deferred {
+	background-color: #705b4e;
+}

lesscpy/test/css/mixin-args-nested.min.css

@@ -20,3 +20,4 @@
 .tx{padding:3px;margin:1px;}
 .ty{padding:7px;margin:3px;}
 .font{font-family:Georgia,"Times New Roman",Times,serif;}
+.deferred{background-color:#705b4e;}

lesscpy/test/less/mixin-args-nested.less

@@ -98,4 +98,18 @@
 }
 .font {
 	#font > .serif();
+}
+/*
+	Deferred calls.
+*/
+.gradientBar(@primaryColor, @secondaryColor) {
+  	#gradient > .vertical(@primaryColor, @secondaryColor);
+}
+#gradient {
+  	.vertical(@startColor: #555, @endColor: #333) {
+    	background-color: mix(@startColor, @endColor, 60%);
+  	}
+}
+.deferred {
+	.gradientBar(#555, #964);
 }