parse() is now asynch, and uses a callback

benchmark/less-benchmark.js

@@ -16,33 +16,35 @@ fs.stat(file, function (e, stats) {
                      parseInt(data.length / 1024) + " KB)", "");
 
             start = new(Date);
-            tree = less.parser.parse(data);
-            end = new(Date);
 
-            if (less.parser.error) {
-                process.stdio.writeError(less.parser.error.message);
-                process.exit(3);
-            }
+            less.parser.parse(data, function (err, tree) {
+                end = new(Date);
 
-            total = end - start;
+                total = end - start;
 
-            sys.puts("Parsing: " +
-                     total + " ms (" +
-                     parseInt(1000 / total *
-                     data.length / 1024) + " KB\/s)");
+                sys.puts("Parsing: " +
+                         total + " ms (" +
+                         parseInt(1000 / total *
+                         data.length / 1024) + " KB\/s)");
 
-            start = new(Date);
-            css = tree.toCSS([], {frames: []});
-            end = new(Date);
+                start = new(Date);
+                css = tree.toCSS([], {frames: []});
+                end = new(Date);
+
+                sys.puts("Generation: " + (end - start) + " ms (" +
+                         parseInt(1000 / (end - start) *
+                         data.length / 1024) + " KB\/s)");
 
-            sys.puts("Generation: " + (end - start) + " ms (" +
-                     parseInt(1000 / (end - start) *
-                     data.length / 1024) + " KB\/s)");
+                total += end - start;
 
-            total += end - start;
+                sys.puts("Total: " + total + "ms (" +
+                         parseInt(1000 / total * data.length / 1024) + " KB/s)");
 
-            sys.puts("Total: " + total + "ms (" +
-                     parseInt(1000 / total * data.length / 1024) + " KB/s)");
+                if (err) {
+                    process.stdio.writeError(err.message);
+                    process.exit(3);
+                }
+            });
         });
     });
 });

lib/less/parser.js

@@ -138,16 +138,16 @@ less.parser = {
     optimization: 2,
 
     //
-    // Parse an input string into an abstract syntax tree
+    // Parse an input string into an abstract syntax tree,
+    // call `callback` when done.
     //
-    parse: function (str) {
-        var root, start, end, zone, line, buff = [], c;
+    parse: function (str, callback) {
+        var root, start, end, zone, line, buff = [], c, error = null;
 
         i = j = current = 0;
         chunks = [];
         input = str.replace(/\r\n/g, '\n');
         inputLength = input.length;
-        this.error = null;
 
         // Split the input into chunks,
         // Either delimited by /\n\n/ or
@@ -200,9 +200,9 @@ less.parser = {
                    stylize(stylize(input[i], 'inverse') +
                    input.slice(i + 1, end),'yellow') + '\033[0m\n';
 
-            this.error = { name: "ParseError", message: "Parse Error on line " + line + ":\n" + zone };
+            error = { name: "ParseError", message: "Parse Error on line " + line + ":\n" + zone };
         }
-        return root;
+        callback(error, root);
     },
 
     //

test/less-test.js

@@ -42,18 +42,18 @@ function toCSS(path, callback) {
     read(path, function (e, str) {
         if (e) { return callback(e) }
 
-        tree = less.parser.parse(str);
-
-        if (less.parser.error) {
-            callback(less.parser.error);
-        } else {
-            try {
-                css = tree.toCSS([], {frames: []});
-                callback(null, css);
-            } catch (e) {
-                callback(e);
+        less.parser.parse(str, function (err, tree) {
+            if (err) {
+                callback(err);
+            } else {
+                try {
+                    css = tree.toCSS([], {frames: []});
+                    callback(null, css);
+                } catch (e) {
+                    callback(e);
+                }
             }
-        }
+        });
     });
 }