| // 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.yaml_node; |
| |
| import 'dart:collection' as collection; |
| |
| import 'package:collection/collection.dart'; |
| import 'package:source_span/source_span.dart'; |
| |
| import 'null_span.dart'; |
| import 'style.dart'; |
| import 'yaml_node_wrapper.dart'; |
| |
| /// An interface for parsed nodes from a YAML source tree. |
| /// |
| /// [YamlMap]s and [YamlList]s implement this interface in addition to the |
| /// normal [Map] and [List] interfaces, so any maps and lists will be |
| /// [YamlNode]s regardless of how they're accessed. |
| /// |
| /// Scalars values like strings and numbers, on the other hand, don't have this |
| /// interface by default. Instead, they can be accessed as [YamlScalar]s via |
| /// [YamlMap.nodes] or [YamlList.nodes]. |
| abstract class YamlNode { |
| /// The source span for this node. |
| /// |
| /// [SourceSpan.message] can be used to produce a human-friendly message about |
| /// this node. |
| SourceSpan get span => _span; |
| |
| SourceSpan _span; |
| |
| /// The inner value of this node. |
| /// |
| /// For [YamlScalar]s, this will return the wrapped value. For [YamlMap] and |
| /// [YamlList], it will return [this], since they already implement [Map] and |
| /// [List], respectively. |
| get value; |
| } |
| |
| /// A read-only [Map] parsed from YAML. |
| class YamlMap extends YamlNode with collection.MapMixin, UnmodifiableMapMixin { |
| /// A view of [this] where the keys and values are guaranteed to be |
| /// [YamlNode]s. |
| /// |
| /// The key type is `dynamic` to allow values to be accessed using |
| /// non-[YamlNode] keys, but [Map.keys] and [Map.forEach] will always expose |
| /// them as [YamlNode]s. For example, for `{"foo": [1, 2, 3]}` [nodes] will be |
| /// a map from a [YamlScalar] to a [YamlList], but since the key type is |
| /// `dynamic` `map.nodes["foo"]` will still work. |
| final Map<dynamic, YamlNode> nodes; |
| |
| /// The style used for the map in the original document. |
| final CollectionStyle style; |
| |
| Map get value => this; |
| |
| Iterable get keys => nodes.keys.map((node) => node.value); |
| |
| /// Creates an empty YamlMap. |
| /// |
| /// This map's [span] won't have useful location information. However, it will |
| /// have a reasonable implementation of [SourceSpan.message]. If [sourceUrl] |
| /// is passed, it's used as the [SourceSpan.sourceUrl]. |
| /// |
| /// [sourceUrl] may be either a [String], a [Uri], or `null`. |
| factory YamlMap({sourceUrl}) => |
| new YamlMapWrapper(const {}, sourceUrl); |
| |
| /// Wraps a Dart map so that it can be accessed (recursively) like a |
| /// [YamlMap]. |
| /// |
| /// Any [SourceSpan]s returned by this map or its children will be dummies |
| /// without useful location information. However, they will have a reasonable |
| /// implementation of [SourceSpan.getLocationMessage]. If [sourceUrl] is |
| /// passed, it's used as the [SourceSpan.sourceUrl]. |
| /// |
| /// [sourceUrl] may be either a [String], a [Uri], or `null`. |
| factory YamlMap.wrap(Map dartMap, {sourceUrl}) => |
| new YamlMapWrapper(dartMap, sourceUrl); |
| |
| /// Users of the library should not use this constructor. |
| YamlMap.internal(Map<dynamic, YamlNode> nodes, SourceSpan span, this.style) |
| : nodes = new UnmodifiableMapView<dynamic, YamlNode>(nodes) { |
| _span = span; |
| } |
| |
| operator [](key) { |
| var node = nodes[key]; |
| return node == null ? null : node.value; |
| } |
| } |
| |
| // TODO(nweiz): Use UnmodifiableListMixin when issue 18970 is fixed. |
| /// A read-only [List] parsed from YAML. |
| class YamlList extends YamlNode with collection.ListMixin { |
| final List<YamlNode> nodes; |
| |
| /// The style used for the list in the original document. |
| final CollectionStyle style; |
| |
| List get value => this; |
| |
| int get length => nodes.length; |
| |
| set length(int index) { |
| throw new UnsupportedError("Cannot modify an unmodifiable List"); |
| } |
| |
| /// Creates an empty YamlList. |
| /// |
| /// This list's [span] won't have useful location information. However, it |
| /// will have a reasonable implementation of [SourceSpan.message]. If |
| /// [sourceUrl] is passed, it's used as the [SourceSpan.sourceUrl]. |
| /// |
| /// [sourceUrl] may be either a [String], a [Uri], or `null`. |
| factory YamlList({sourceUrl}) => |
| new YamlListWrapper(const [], sourceUrl); |
| |
| /// Wraps a Dart list so that it can be accessed (recursively) like a |
| /// [YamlList]. |
| /// |
| /// Any [SourceSpan]s returned by this list or its children will be dummies |
| /// without useful location information. However, they will have a reasonable |
| /// implementation of [SourceSpan.getLocationMessage]. If [sourceUrl] is |
| /// passed, it's used as the [SourceSpan.sourceUrl]. |
| /// |
| /// [sourceUrl] may be either a [String], a [Uri], or `null`. |
| factory YamlList.wrap(List dartList, {sourceUrl}) => |
| new YamlListWrapper(dartList, sourceUrl); |
| |
| /// Users of the library should not use this constructor. |
| YamlList.internal(List<YamlNode> nodes, SourceSpan span, this.style) |
| : nodes = new UnmodifiableListView<YamlNode>(nodes) { |
| _span = span; |
| } |
| |
| operator [](int index) => nodes[index].value; |
| |
| operator []=(int index, value) { |
| throw new UnsupportedError("Cannot modify an unmodifiable List"); |
| } |
| } |
| |
| /// A wrapped scalar value parsed from YAML. |
| class YamlScalar extends YamlNode { |
| final value; |
| |
| /// The style used for the scalar in the original document. |
| final ScalarStyle style; |
| |
| /// Wraps a Dart value in a [YamlScalar]. |
| /// |
| /// This scalar's [span] won't have useful location information. However, it |
| /// will have a reasonable implementation of [SourceSpan.message]. If |
| /// [sourceUrl] is passed, it's used as the [SourceSpan.sourceUrl]. |
| /// |
| /// [sourceUrl] may be either a [String], a [Uri], or `null`. |
| YamlScalar.wrap(this.value, {sourceUrl}) |
| : style = ScalarStyle.ANY { |
| _span = new NullSpan(sourceUrl); |
| } |
| |
| /// Users of the library should not use this constructor. |
| YamlScalar.internal(this.value, SourceSpan span, this.style) { |
| _span = span; |
| } |
| |
| String toString() => value.toString(); |
| } |
| |
| /// Sets the source span of a [YamlNode]. |
| /// |
| /// This method is not exposed publicly. |
| void setSpan(YamlNode node, SourceSpan span) { |
| node._span = span; |
| } |