New CSS parser written in Dart to replace pyparser

utils/css/tool.dart

+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#library('csstool');
+
+#import('../../frog/file_system.dart');
+#import('../../frog/file_system_node.dart');
+#import('../../frog/lang.dart', prefix:'lang');
+#import('css.dart');
+
+FileSystem files;
+
+/** Invokes [callback] and returns how long it took to execute in ms. */
+num time(callback()) {
+  final watch = new Stopwatch();
+  watch.start();
+  callback();
+  watch.stop();
+  return watch.elapsedInMs();
+}
+
+printStats(num elapsed, [String filename = '']) {
+  print('Parsed\033[32m ${filename}\033[0m in ${elapsed} msec.');
+}
+
+/**
+ * Run from the `utils/css` directory.
+ */
+void main() {
+  // process.argv[0] == node and process.argv[1] == minfrog
+  assert(process.argv.length == 4);
+
+  String sourceFullFn = process.argv[2];
+  String outputFullFn = process.argv[3];
+
+  String sourcePath;
+  String sourceFilename;
+  int idxBeforeFilename = sourceFullFn.lastIndexOf('/');
+  if (idxBeforeFilename >= 0) {
+    sourcePath = sourceFullFn.substring(0, idxBeforeFilename + 1);
+    sourceFilename = sourceFullFn.substring(idxBeforeFilename + 1);
+  }
+
+  String outPath;
+  idxBeforeFilename = outputFullFn.lastIndexOf('/');
+  if (idxBeforeFilename >= 0) {
+    outPath = outputFullFn.substring(0, idxBeforeFilename + 1);
+  }
+
+  initCssWorld();
+
+  files = new NodeFileSystem();
+  if (!files.fileExists(sourceFullFn)) {
+    // Display colored error message if file is missing.
+    print("\033[31mCSS source file missing - ${sourceFullFn}\033[0m");
+  } else {
+    String source = files.readAll(sourceFullFn);
+
+    Stylesheet stylesheet;
+
+    final elapsed = time(() {
+      Parser parser = new Parser(
+          new lang.SourceFile(sourceFullFn, source), 0, files, sourcePath);
+      stylesheet = parser.parse();
+    });
+
+    printStats(elapsed, sourceFullFn);
+
+    StringBuffer buff = new StringBuffer(
+      '/* File generated by SCSS from source ${sourceFilename}\n' +
+      ' * Do not edit.\n' +
+      ' */\n\n');
+    buff.add(stylesheet.toString());
+
+    files.writeString(outputFullFn, buff.toString());
+    print("Generated file ${outputFullFn}");
+
+    // Generate CSS.dart file.
+    String genDartClassFile = Generate.dartClass(files, outPath, stylesheet,
+        sourceFilename);
+    print("Generated file ${genDartClassFile}");
+  }
+}