move polymer.dart into dart svn

pkg/polymer/lib/src/messages.dart

+// Copyright (c) 2012, 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 messages;
+
+import 'dart:json' as json;
+
+import 'package:barback/barback.dart' show TransformLogger;
+import 'package:source_maps/span.dart' show Span;
+import 'package:logging/logging.dart' show Level;
+
+import 'compiler_options.dart';
+import 'utils.dart';
+
+/** Map between error levels and their display color. */
+final Map<Level, String> _ERROR_COLORS = (() {
+  var colorsMap = new Map<Level, String>();
+  colorsMap[Level.SEVERE] = RED_COLOR;
+  colorsMap[Level.WARNING] = MAGENTA_COLOR;
+  colorsMap[Level.INFO] = GREEN_COLOR;
+  return colorsMap;
+})();
+
+/** A single message from the compiler. */
+class Message {
+  final Level level;
+  final String message;
+  final Span span;
+  final bool useColors;
+
+  Message(this.level, this.message, {this.span, this.useColors: false});
+
+  String get kind => level == Level.SEVERE ? 'error' :
+      (level == Level.WARNING ? 'warning' : 'info');
+
+  String toString() {
+    var output = new StringBuffer();
+    bool colors = useColors && _ERROR_COLORS.containsKey(level);
+    var levelColor =  _ERROR_COLORS[level];
+    if (colors) output.write(levelColor);
+    output..write(kind)..write(' ');
+    if (colors) output.write(NO_COLOR);
+
+    if (span == null) {
+      output.write(message);
+    } else {
+      output.write(span.getLocationMessage(message, useColors: colors,
+          color: levelColor));
+    }
+
+    return output.toString();
+  }
+
+  String toJson() {
+    if (span == null) return toString();
+    return json.stringify([{
+      'method': kind,
+      'params': {
+        'file': span.sourceUrl,
+        'message': message,
+        'line': span.start.line + 1,
+        'charStart': span.start.offset,
+        'charEnd': span.end.offset,
+      }
+    }]);
+  }
+}
+
+/**
+ * This class tracks and prints information, warnings, and errors emitted by the
+ * compiler.
+ */
+class Messages implements TransformLogger {
+  final CompilerOptions options;
+  final bool shouldPrint;
+
+  final List<Message> messages = <Message>[];
+
+  Messages({CompilerOptions options, this.shouldPrint: true})
+      : options = options != null ? options : new CompilerOptions();
+
+  /**
+   * Creates a new instance of [Messages] which doesn't write messages to
+   * the console.
+   */
+  Messages.silent(): this(shouldPrint: false);
+
+  /**
+   * True if we have an error that prevents correct codegen.
+   * For example, if we failed to read an input file.
+   */
+  bool get hasErrors => messages.any((m) => m.level == Level.SEVERE);
+
+  // Convenience methods for testing
+  int get length => messages.length;
+
+  Message operator[](int index) => messages[index];
+
+  void clear() {
+    messages.clear();
+  }
+
+  /** [message] is considered a static compile-time error by the Dart lang. */
+  void error(String message, [Span span]) {
+    var msg = new Message(Level.SEVERE, message, span: span,
+        useColors: options.useColors);
+
+    messages.add(msg);
+    printMessage(msg);
+  }
+
+  /** [message] is considered a type warning by the Dart lang. */
+  void warning(String message, [Span span]) {
+    if (options.warningsAsErrors) {
+      error(message, span);
+    } else {
+      var msg = new Message(Level.WARNING, message,
+          span: span, useColors: options.useColors);
+
+      messages.add(msg);
+      printMessage(msg);
+    }
+  }
+
+  /// the list of error messages. Empty list, if there are no error messages.
+  List<Message> get errors =>
+        messages.where((m) => m.level == Level.SEVERE).toList();
+
+  /// the list of warning messages. Empty list if there are no warning messages.
+  List<Message> get warnings =>
+        messages.where((m) => m.level == Level.WARNING).toList();
+
+  /**
+   * [message] at [span] will tell the user about what the compiler
+   * is doing.
+   */
+  void info(String message, [Span span]) {
+    var msg = new Message(Level.INFO, message, span: span,
+        useColors: options.useColors);
+
+    messages.add(msg);
+    if (options.verbose) printMessage(msg);
+  }
+
+  void printMessage(msg) {
+    if (shouldPrint) print(options.jsonFormat ? msg.toJson() : msg);
+  }
+}