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1 // Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file | 1 // Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file |
2 // for details. All rights reserved. Use of this source code is governed by a | 2 // for details. All rights reserved. Use of this source code is governed by a |
3 // BSD-style license that can be found in the LICENSE file. | 3 // BSD-style license that can be found in the LICENSE file. |
4 | 4 |
5 part of yaml; | 5 library composer; |
| 6 |
| 7 import 'model.dart'; |
| 8 import 'visitor.dart'; |
| 9 import 'yaml_exception.dart'; |
6 | 10 |
7 /// Takes a parsed YAML document (what the spec calls the "serialization tree") | 11 /// Takes a parsed YAML document (what the spec calls the "serialization tree") |
8 /// and resolves aliases, resolves tags, and parses scalars to produce the | 12 /// and resolves aliases, resolves tags, and parses scalars to produce the |
9 /// "representation graph". | 13 /// "representation graph". |
10 class _Composer extends _Visitor { | 14 class Composer extends Visitor { |
11 /// The root node of the serialization tree. | 15 /// The root node of the serialization tree. |
12 _Node root; | 16 final Node _root; |
13 | 17 |
14 /// Map from anchor names to the most recent representation graph node with | 18 /// Map from anchor names to the most recent representation graph node with |
15 /// that anchor. | 19 /// that anchor. |
16 Map<String, _Node> anchors; | 20 final _anchors = <String, Node>{}; |
17 | 21 |
18 /// The next id to use for the represenation graph's anchors. The spec doesn't | 22 /// The next id to use for the represenation graph's anchors. The spec doesn't |
19 /// use anchors in the representation graph, but we do so that the constructor | 23 /// use anchors in the representation graph, but we do so that the constructor |
20 /// can ensure that the same node in the representation graph produces the | 24 /// can ensure that the same node in the representation graph produces the |
21 /// same native object. | 25 /// same native object. |
22 int idCounter; | 26 var _idCounter = 0; |
23 | 27 |
24 _Composer(this.root) : this.anchors = <String, _Node>{}, this.idCounter = 0; | 28 Composer(this._root); |
25 | 29 |
26 /// Runs the Composer to produce a representation graph. | 30 /// Runs the Composer to produce a representation graph. |
27 _Node compose() => root.visit(this); | 31 Node compose() => _root.visit(this); |
28 | 32 |
29 /// Returns the anchor to which an alias node refers. | 33 /// Returns the anchor to which an alias node refers. |
30 _Node visitAlias(_AliasNode alias) { | 34 Node visitAlias(AliasNode alias) { |
31 if (!anchors.containsKey(alias.anchor)) { | 35 if (!_anchors.containsKey(alias.anchor)) { |
32 throw new YamlException("no anchor for alias ${alias.anchor}"); | 36 throw new YamlException("no anchor for alias ${alias.anchor}"); |
33 } | 37 } |
34 return anchors[alias.anchor]; | 38 return _anchors[alias.anchor]; |
35 } | 39 } |
36 | 40 |
37 /// Parses a scalar node according to its tag, or auto-detects the type if no | 41 /// Parses a scalar node according to its tag, or auto-detects the type if no |
38 /// tag exists. Currently this only supports the YAML core type schema. | 42 /// tag exists. Currently this only supports the YAML core type schema. |
39 _Node visitScalar(_ScalarNode scalar) { | 43 Node visitScalar(ScalarNode scalar) { |
40 if (scalar.tag.name == "!") { | 44 if (scalar.tag.name == "!") { |
41 return setAnchor(scalar, parseString(scalar.content)); | 45 return setAnchor(scalar, parseString(scalar.content)); |
42 } else if (scalar.tag.name == "?") { | 46 } else if (scalar.tag.name == "?") { |
43 for (var fn in [parseNull, parseBool, parseInt, parseFloat]) { | 47 for (var fn in [parseNull, parseBool, parseInt, parseFloat]) { |
44 var result = fn(scalar.content); | 48 var result = fn(scalar.content); |
45 if (result != null) return result; | 49 if (result != null) return result; |
46 } | 50 } |
47 return setAnchor(scalar, parseString(scalar.content)); | 51 return setAnchor(scalar, parseString(scalar.content)); |
48 } | 52 } |
49 | 53 |
50 // TODO(nweiz): support the full YAML type repository | 54 // TODO(nweiz): support the full YAML type repository |
51 var tagParsers = { | 55 var tagParsers = { |
52 'null': parseNull, 'bool': parseBool, 'int': parseInt, | 56 'null': parseNull, 'bool': parseBool, 'int': parseInt, |
53 'float': parseFloat, 'str': parseString | 57 'float': parseFloat, 'str': parseString |
54 }; | 58 }; |
55 | 59 |
56 for (var key in tagParsers.keys) { | 60 for (var key in tagParsers.keys) { |
57 if (scalar.tag.name != _Tag.yaml(key)) continue; | 61 if (scalar.tag.name != Tag.yaml(key)) continue; |
58 var result = tagParsers[key](scalar.content); | 62 var result = tagParsers[key](scalar.content); |
59 if (result != null) return setAnchor(scalar, result); | 63 if (result != null) return setAnchor(scalar, result); |
60 throw new YamlException('invalid literal for $key: "${scalar.content}"'); | 64 throw new YamlException('invalid literal for $key: "${scalar.content}"'); |
61 } | 65 } |
62 | 66 |
63 throw new YamlException('undefined tag: "${scalar.tag.name}"'); | 67 throw new YamlException('undefined tag: "${scalar.tag.name}"'); |
64 } | 68 } |
65 | 69 |
66 /// Assigns a tag to the sequence and recursively composes its contents. | 70 /// Assigns a tag to the sequence and recursively composes its contents. |
67 _Node visitSequence(_SequenceNode seq) { | 71 Node visitSequence(SequenceNode seq) { |
68 var tagName = seq.tag.name; | 72 var tagName = seq.tag.name; |
69 if (tagName != "!" && tagName != "?" && tagName != _Tag.yaml("seq")) { | 73 if (tagName != "!" && tagName != "?" && tagName != Tag.yaml("seq")) { |
70 throw new YamlException("invalid tag for sequence: ${tagName}"); | 74 throw new YamlException("invalid tag for sequence: ${tagName}"); |
71 } | 75 } |
72 | 76 |
73 var result = setAnchor(seq, new _SequenceNode(_Tag.yaml("seq"), null)); | 77 var result = setAnchor(seq, new SequenceNode(Tag.yaml("seq"), null)); |
74 result.content = super.visitSequence(seq); | 78 result.content = super.visitSequence(seq); |
75 return result; | 79 return result; |
76 } | 80 } |
77 | 81 |
78 /// Assigns a tag to the mapping and recursively composes its contents. | 82 /// Assigns a tag to the mapping and recursively composes its contents. |
79 _Node visitMapping(_MappingNode map) { | 83 Node visitMapping(MappingNode map) { |
80 var tagName = map.tag.name; | 84 var tagName = map.tag.name; |
81 if (tagName != "!" && tagName != "?" && tagName != _Tag.yaml("map")) { | 85 if (tagName != "!" && tagName != "?" && tagName != Tag.yaml("map")) { |
82 throw new YamlException("invalid tag for mapping: ${tagName}"); | 86 throw new YamlException("invalid tag for mapping: ${tagName}"); |
83 } | 87 } |
84 | 88 |
85 var result = setAnchor(map, new _MappingNode(_Tag.yaml("map"), null)); | 89 var result = setAnchor(map, new MappingNode(Tag.yaml("map"), null)); |
86 result.content = super.visitMapping(map); | 90 result.content = super.visitMapping(map); |
87 return result; | 91 return result; |
88 } | 92 } |
89 | 93 |
90 /// If the serialization tree node [anchored] has an anchor, records that | 94 /// If the serialization tree node [anchored] has an anchor, records that |
91 /// that anchor is pointing to the representation graph node [result]. | 95 /// that anchor is pointing to the representation graph node [result]. |
92 _Node setAnchor(_Node anchored, _Node result) { | 96 Node setAnchor(Node anchored, Node result) { |
93 if (anchored.anchor == null) return result; | 97 if (anchored.anchor == null) return result; |
94 result.anchor = '${idCounter++}'; | 98 result.anchor = '${_idCounter++}'; |
95 anchors[anchored.anchor] = result; | 99 _anchors[anchored.anchor] = result; |
96 return result; | 100 return result; |
97 } | 101 } |
98 | 102 |
99 /// Parses a null scalar. | 103 /// Parses a null scalar. |
100 _ScalarNode parseNull(String content) { | 104 ScalarNode parseNull(String content) { |
101 if (!new RegExp(r"^(null|Null|NULL|~|)$").hasMatch(content)) return null; | 105 if (!new RegExp(r"^(null|Null|NULL|~|)$").hasMatch(content)) return null; |
102 return new _ScalarNode(_Tag.yaml("null"), value: null); | 106 return new ScalarNode(Tag.yaml("null"), value: null); |
103 } | 107 } |
104 | 108 |
105 /// Parses a boolean scalar. | 109 /// Parses a boolean scalar. |
106 _ScalarNode parseBool(String content) { | 110 ScalarNode parseBool(String content) { |
107 var match = new RegExp(r"^(?:(true|True|TRUE)|(false|False|FALSE))$"). | 111 var match = new RegExp(r"^(?:(true|True|TRUE)|(false|False|FALSE))$"). |
108 firstMatch(content); | 112 firstMatch(content); |
109 if (match == null) return null; | 113 if (match == null) return null; |
110 return new _ScalarNode(_Tag.yaml("bool"), value: match.group(1) != null); | 114 return new ScalarNode(Tag.yaml("bool"), value: match.group(1) != null); |
111 } | 115 } |
112 | 116 |
113 /// Parses an integer scalar. | 117 /// Parses an integer scalar. |
114 _ScalarNode parseInt(String content) { | 118 ScalarNode parseInt(String content) { |
115 var match = new RegExp(r"^[-+]?[0-9]+$").firstMatch(content); | 119 var match = new RegExp(r"^[-+]?[0-9]+$").firstMatch(content); |
116 if (match != null) { | 120 if (match != null) { |
117 return new _ScalarNode(_Tag.yaml("int"), | 121 return new ScalarNode(Tag.yaml("int"), |
118 value: int.parse(match.group(0))); | 122 value: int.parse(match.group(0))); |
119 } | 123 } |
120 | 124 |
121 match = new RegExp(r"^0o([0-7]+)$").firstMatch(content); | 125 match = new RegExp(r"^0o([0-7]+)$").firstMatch(content); |
122 if (match != null) { | 126 if (match != null) { |
123 int n = int.parse(match.group(1), radix: 8); | 127 int n = int.parse(match.group(1), radix: 8); |
124 return new _ScalarNode(_Tag.yaml("int"), value: n); | 128 return new ScalarNode(Tag.yaml("int"), value: n); |
125 } | 129 } |
126 | 130 |
127 match = new RegExp(r"^0x[0-9a-fA-F]+$").firstMatch(content); | 131 match = new RegExp(r"^0x[0-9a-fA-F]+$").firstMatch(content); |
128 if (match != null) { | 132 if (match != null) { |
129 return new _ScalarNode(_Tag.yaml("int"), | 133 return new ScalarNode(Tag.yaml("int"), |
130 value: int.parse(match.group(0))); | 134 value: int.parse(match.group(0))); |
131 } | 135 } |
132 | 136 |
133 return null; | 137 return null; |
134 } | 138 } |
135 | 139 |
136 /// Parses a floating-point scalar. | 140 /// Parses a floating-point scalar. |
137 _ScalarNode parseFloat(String content) { | 141 ScalarNode parseFloat(String content) { |
138 var match = new RegExp( | 142 var match = new RegExp( |
139 r"^[-+]?(\.[0-9]+|[0-9]+(\.[0-9]*)?)([eE][-+]?[0-9]+)?$"). | 143 r"^[-+]?(\.[0-9]+|[0-9]+(\.[0-9]*)?)([eE][-+]?[0-9]+)?$"). |
140 firstMatch(content); | 144 firstMatch(content); |
141 if (match != null) { | 145 if (match != null) { |
142 // YAML allows floats of the form "0.", but Dart does not. Fix up those | 146 // YAML allows floats of the form "0.", but Dart does not. Fix up those |
143 // floats by removing the trailing dot. | 147 // floats by removing the trailing dot. |
144 var matchStr = match.group(0).replaceAll(new RegExp(r"\.$"), ""); | 148 var matchStr = match.group(0).replaceAll(new RegExp(r"\.$"), ""); |
145 return new _ScalarNode(_Tag.yaml("float"), | 149 return new ScalarNode(Tag.yaml("float"), |
146 value: double.parse(matchStr)); | 150 value: double.parse(matchStr)); |
147 } | 151 } |
148 | 152 |
149 match = new RegExp(r"^([+-]?)\.(inf|Inf|INF)$").firstMatch(content); | 153 match = new RegExp(r"^([+-]?)\.(inf|Inf|INF)$").firstMatch(content); |
150 if (match != null) { | 154 if (match != null) { |
151 var value = match.group(1) == "-" ? -double.INFINITY : double.INFINITY; | 155 var value = match.group(1) == "-" ? -double.INFINITY : double.INFINITY; |
152 return new _ScalarNode(_Tag.yaml("float"), value: value); | 156 return new ScalarNode(Tag.yaml("float"), value: value); |
153 } | 157 } |
154 | 158 |
155 match = new RegExp(r"^\.(nan|NaN|NAN)$").firstMatch(content); | 159 match = new RegExp(r"^\.(nan|NaN|NAN)$").firstMatch(content); |
156 if (match != null) { | 160 if (match != null) { |
157 return new _ScalarNode(_Tag.yaml("float"), value: double.NAN); | 161 return new ScalarNode(Tag.yaml("float"), value: double.NAN); |
158 } | 162 } |
159 | 163 |
160 return null; | 164 return null; |
161 } | 165 } |
162 | 166 |
163 /// Parses a string scalar. | 167 /// Parses a string scalar. |
164 _ScalarNode parseString(String content) => | 168 ScalarNode parseString(String content) => |
165 new _ScalarNode(_Tag.yaml("str"), value: content); | 169 new ScalarNode(Tag.yaml("str"), value: content); |
166 } | 170 } |
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