Refactored some of the evaluation mechanisms

- Don't call `eval` from `toCSS`
- Every node responds to `eval`

lib/less/parser.js

@@ -406,7 +406,7 @@ less.Parser = function Parser(env) {
                     value = $(this.entities.quoted) || $(/[-a-zA-Z0-9_%@$\/.&=:;#+?]+/g);
                     if (! $(')')) throw new(Error)("missing closing ) for url()");
 
-                    return new(tree.URL)(value);
+                    return new(tree.URL)(value.value ? value : new(tree.Anonymous)(value));
                 },
 
                 //
@@ -719,7 +719,7 @@ less.Parser = function Parser(env) {
                 if (name = $(this.property) || $(this.variable)) {
                     if ((name[0] != '@') && (match = peek(/([^@+\/*(;{}-]*);/g))) {
                         i += match[0].length - 1;
-                        value = match[1];
+                        value = new(tree.Anonymous)(match[1]);
                     } else if (name === "font") {
                         value = $(this.font);
                     } else {

lib/less/tree/alpha.js

@@ -5,6 +5,7 @@ tree.Alpha = function Alpha(val) {
 };
 tree.Alpha.prototype = {
     toCSS: function () {
-        return "alpha(opacity=" + (this.value.toCSS ? this.value.toCSS() : this.value) + ")";
-    }
+        return "alpha(opacity=" + this.value.toCSS() + ")";
+    },
+    eval: function () { return this }
 };

lib/less/tree/comment.js

@@ -6,5 +6,5 @@ tree.Comment = function Comment(value) {
 tree.Comment.prototype = {
     toCSS: function () {
         return this.value;
-    }
+    },
 };

lib/less/tree/directive.js

@@ -18,3 +18,4 @@ tree.Directive.prototype.toCSS = function () {
         return this.name + ' ' + this.value.toCSS() + ';\n';
     }
 };
+tree.Directive.prototype.eval = function () { return this }

lib/less/tree/expression.js

@@ -11,14 +11,9 @@ tree.Expression.prototype = {
             return this.value[0].eval(env);
         }
     },
-    toCSS: function (env) {
-        var evaled;
-        evaled = this.value.map(function (e) {
-            if (e.eval) {
-                e = e.eval(env);
-            }
-            return e.toCSS ? e.toCSS(env) : e;
-        });
-        return evaled.join(' ');
+    toCSS: function () {
+        return this.value.map(function (e) {
+            return e.toCSS();
+        }).join(' ');
     }
 };

lib/less/tree/mixin.js

@@ -69,7 +69,7 @@ tree.mixin.Definition.prototype = {
         for (var i = 0; i < Math.min(argsLength, this.arity); i++) {
             if (!this.params[i].name) {
                 if (args[i].wildcard) { continue }
-                else if (args[i].toCSS(env) != this.params[i].value.toCSS(env)) {
+                else if (args[i].eval(env).toCSS() != this.params[i].value.eval(env).toCSS()) {
                     return false;
                 }
             }

lib/less/tree/rule.js

@@ -8,11 +8,10 @@ tree.Rule = function Rule(name, value) {
         this.variable = true;
     } else { this.variable = false }
 };
-tree.Rule.prototype.toCSS = function (env) {
+tree.Rule.prototype.toCSS = function () {
     if (this.variable) { return "" }
     else {
-        return this.name + ": " +
-              (this.value.toCSS ? this.value.toCSS(env) : this.value) + ";";
+        return this.name + ": " + this.value.toCSS() + ";";
     }
 };
 
@@ -27,17 +26,16 @@ tree.Value = function Value(value) {
 tree.Value.prototype = {
     eval: function (env) {
         if (this.value.length === 1) {
-            return this.value[0].eval ? this.value[0].eval(env)
-                                      : this.value[0];
+            return this.value[0].eval(env);
         } else {
             return new(tree.Value)(this.value.map(function (v) {
                 return v.eval(env);
             }));
         }
     },
-    toCSS: function (env) {
+    toCSS: function () {
         return this.value.map(function (e) {
-            return e.toCSS ? e.toCSS(env) : e;
+            return e.toCSS();
         }).join(', ');
     }
 };
@@ -50,5 +48,6 @@ tree.Shorthand = function Shorthand(a, b) {
 tree.Shorthand.prototype = {
     toCSS: function (env) {
         return this.a.toCSS(env) + "/" + this.b.toCSS(env);
-    }
+    },
+    eval: function () { return this }
 };

lib/less/tree/ruleset.js

@@ -16,7 +16,7 @@ tree.Ruleset.prototype = {
             } else if (rule instanceof tree.mixin.Call) {
                 Array.prototype.push.apply(rules, rule.eval(context));
             } else {
-                rules.push(rule.eval ? rule.eval(context) : rule);
+                rules.push(rule.eval(context));
             }
         });
         this.rules = rules;
@@ -126,7 +126,7 @@ tree.Ruleset.prototype = {
                 }
             } else {
                 if (rule.toCSS && !rule.variable) {
-                    rules.push(rule.toCSS(env));
+                    rules.push(rule.eval(env).toCSS());
                 } else if (rule.value && !rule.variable) {
                     rules.push(rule.value.toString());
                 }

lib/less/tree/url.js

@@ -5,6 +5,7 @@ tree.URL = function URL(val) {
 };
 tree.URL.prototype = {
     toCSS: function () {
-        return "url(" + (this.value.toCSS ? this.value.toCSS() : this.value) + ")";
-    }
+        return "url(" + this.value.toCSS() + ")";
+    },
+    eval: function () { return this }
 };

lib/less/tree/variable.js

@@ -2,7 +2,6 @@ if (typeof(require) !== 'undefined') { var tree = require('less/tree') }
 
 tree.Variable = function Variable(name) { this.name = name };
 tree.Variable.prototype = {
-    toCSS: function (env) { return this.eval(env).toCSS(env) },
     eval: function (env) {
         var variable, v, name = this.name;