// 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 yaml;

import 'dart:math' as Math;

import 'deep_equals.dart';

part 'yaml_map.dart';
part 'model.dart';
part 'parser.dart';
part 'visitor.dart';
part 'composer.dart';
part 'constructor.dart';

/**
 * Loads a single document from a YAML string. If the string contains more than
 * one document, this throws an error.
 *
 * The return value is mostly normal Dart objects. However, since YAML mappings
 * support some key types that the default Dart map implementation doesn't
 * (null, NaN, booleans, lists, and maps), all maps in the returned document are
 * YamlMaps. These have a few small behavioral differences from the default Map
 * implementation; for details, see the YamlMap class.
 */
loadYaml(String yaml) {
  var stream = loadYamlStream(yaml);
  if (stream.length != 1) {
    throw new YamlException("Expected 1 document, were ${stream.length}");
  }
  return stream[0];
}

/**
 * Loads a stream of documents from a YAML string.
 *
 * The return value is mostly normal Dart objects. However, since YAML mappings
 * support some key types that the default Dart map implementation doesn't
 * (null, NaN, booleans, lists, and maps), all maps in the returned document are
 * YamlMaps. These have a few small behavioral differences from the default Map
 * implementation; for details, see the YamlMap class.
 */
List loadYamlStream(String yaml) {
  return new _Parser(yaml).l_yamlStream().map((doc) =>
      new _Constructor(new _Composer(doc).compose()).construct());
}

/** An error thrown by the YAML processor. */
class YamlException implements Exception {
  String msg;

  YamlException(this.msg);

  String toString() => msg;
}