(doc) comments

lib/less/parser.js

@@ -1038,6 +1038,9 @@ if (typeof(window) !== 'undefined') {
         if (path[0] !== '/' && paths.length > 0) {
             path = paths[0] + path;
         }
+        // We pass `true` as 3rd argument, to force the reload of the import.
+        // This is so we can get the syntax tree as opposed to just the CSS output,
+        // as we need this to evaluate the current stylesheet.
         loadStyleSheet({ href: path, title: path }, callback, true);
     };
 }

lib/less/tree/ruleset.js

@@ -103,7 +103,8 @@ tree.Ruleset.prototype = {
         // push the current ruleset to the frames stack
         env.frames.unshift(this);
 
-        // Evaluate mixins
+        // Evaluate mixin calls and store the frames around mixin definitions,
+        // so they can be evaluated like closures when the time comes.
         for (var i = 0; i < this.rules.length; i++) {
             if (this.rules[i] instanceof tree.mixin.Call) {
                 Array.prototype.splice