Attach source range information to parsed YAML nodes.

pkg/yaml/lib/src/composer.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 yaml.composer;
 
+import 'package:source_maps/source_maps.dart';
+
 import 'model.dart';
 import 'visitor.dart';
 import 'yaml_exception.dart';
 
 /// Takes a parsed YAML document (what the spec calls the "serialization tree")
 /// and resolves aliases, resolves tags, and parses scalars to produce the
 /// "representation graph".
 class Composer extends Visitor {
   /// The root node of the serialization tree.
   final Node _root;
@@ skipping 21 matching lines @@
     }
     return _anchors[alias.anchor];
   }
 
   /// Parses a scalar node according to its tag, or auto-detects the type if no
   /// tag exists.
   ///
   /// Currently this only supports the YAML core type schema.
   Node visitScalar(ScalarNode scalar) {
     if (scalar.tag.name == "!") {
-      return setAnchor(scalar, parseString(scalar.content));
+      return setAnchor(scalar, parseString(scalar.content, scalar.span));

[Bob Nystrom, 2014/06/03 00:33:14]

Would it make more sense to just pass the whole ScalarNode to these methods?

[nweiz, 2014/06/03 02:03:21]

Done.

     } else if (scalar.tag.name == "?") {
       for (var fn in [parseNull, parseBool, parseInt, parseFloat]) {
-        var result = fn(scalar.content);
+        var result = fn(scalar.content, scalar.span);
         if (result != null) return result;
       }
-      return setAnchor(scalar, parseString(scalar.content));
+      return setAnchor(scalar, parseString(scalar.content, scalar.span));
     }
 
     var result = _parseByTag(scalar);
     if (result != null) return setAnchor(scalar, result);
     throw new YamlException('Invalid literal for ${scalar.tag}: '
         '"${scalar.content}".');
   }
 
   ScalarNode _parseByTag(ScalarNode scalar) {
     switch (scalar.tag.name) {
-      case "null": return parseNull(scalar.content);
-      case "bool": return parseBool(scalar.content);
-      case "int": return parseInt(scalar.content);
-      case "float": return parseFloat(scalar.content);
-      case "str": return parseString(scalar.content);
+      case "null": return parseNull(scalar.content, scalar.span);
+      case "bool": return parseBool(scalar.content, scalar.span);
+      case "int": return parseInt(scalar.content, scalar.span);
+      case "float": return parseFloat(scalar.content, scalar.span);
+      case "str": return parseString(scalar.content, scalar.span);
     }
     throw new YamlException('Undefined tag: ${scalar.tag}.');
   }
 
   /// Assigns a tag to the sequence and recursively composes its contents.
   Node visitSequence(SequenceNode seq) {
     var tagName = seq.tag.name;
     if (tagName != "!" && tagName != "?" && tagName != Tag.yaml("seq")) {
       throw new YamlException("Invalid tag for sequence: ${seq.tag}.");
     }
 
-    var result = setAnchor(seq, new SequenceNode(Tag.yaml('seq'), null));
+    var result = setAnchor(seq,
+        new SequenceNode(Tag.yaml('seq'), null, seq.span));
     result.content = super.visitSequence(seq);
     return result;
   }
 
   /// Assigns a tag to the mapping and recursively composes its contents.
   Node visitMapping(MappingNode map) {
     var tagName = map.tag.name;
     if (tagName != "!" && tagName != "?" && tagName != Tag.yaml("map")) {
       throw new YamlException("Invalid tag for mapping: ${map.tag}.");
     }
 
-    var result = setAnchor(map, new MappingNode(Tag.yaml('map'), null));
+    var result = setAnchor(map,
+        new MappingNode(Tag.yaml('map'), null, map.span));
     result.content = super.visitMapping(map);
     return result;
   }
 
   /// If the serialization tree node [anchored] has an anchor, records that
   /// that anchor is pointing to the representation graph node [result].
   Node setAnchor(Node anchored, Node result) {
     if (anchored.anchor == null) return result;
     result.anchor = '${_idCounter++}';
     _anchors[anchored.anchor] = result;
     return result;
   }
 
   /// Parses a null scalar.
-  ScalarNode parseNull(String content) {
+  ScalarNode parseNull(String content, Span span) {
     if (!new RegExp(r"^(null|Null|NULL|~|)$").hasMatch(content)) return null;
-    return new ScalarNode(Tag.yaml("null"), value: null);
+    return new ScalarNode(Tag.yaml("null"), span, value: null);
   }
 
   /// Parses a boolean scalar.
-  ScalarNode parseBool(String content) {
+  ScalarNode parseBool(String content, Span span) {
     var match = new RegExp(r"^(?:(true|True|TRUE)|(false|False|FALSE))$").
       firstMatch(content);
     if (match == null) return null;
-    return new ScalarNode(Tag.yaml("bool"), value: match.group(1) != null);
+    return new ScalarNode(Tag.yaml("bool"), span,
+        value: match.group(1) != null);
   }
 
   /// Parses an integer scalar.
-  ScalarNode parseInt(String content) {
+  ScalarNode parseInt(String content, Span span) {
     var match = new RegExp(r"^[-+]?[0-9]+$").firstMatch(content);
     if (match != null) {
-      return new ScalarNode(Tag.yaml("int"),
+      return new ScalarNode(Tag.yaml("int"), span,
           value: int.parse(match.group(0)));
     }
 
     match = new RegExp(r"^0o([0-7]+)$").firstMatch(content);
     if (match != null) {
       int n = int.parse(match.group(1), radix: 8);
-      return new ScalarNode(Tag.yaml("int"), value: n);
+      return new ScalarNode(Tag.yaml("int"), span, value: n);
     }
 
     match = new RegExp(r"^0x[0-9a-fA-F]+$").firstMatch(content);
     if (match != null) {
-      return new ScalarNode(Tag.yaml("int"),
+      return new ScalarNode(Tag.yaml("int"), span,
           value: int.parse(match.group(0)));
     }
 
     return null;
   }
 
   /// Parses a floating-point scalar.
-  ScalarNode parseFloat(String content) {
+  ScalarNode parseFloat(String content, Span span) {
     var match = new RegExp(
         r"^[-+]?(\.[0-9]+|[0-9]+(\.[0-9]*)?)([eE][-+]?[0-9]+)?$").
       firstMatch(content);
     if (match != null) {
       // YAML allows floats of the form "0.", but Dart does not. Fix up those
       // floats by removing the trailing dot.
       var matchStr = match.group(0).replaceAll(new RegExp(r"\.$"), "");
-      return new ScalarNode(Tag.yaml("float"),
+      return new ScalarNode(Tag.yaml("float"), span,
           value: double.parse(matchStr));
     }
 
     match = new RegExp(r"^([+-]?)\.(inf|Inf|INF)$").firstMatch(content);
     if (match != null) {
       var value = match.group(1) == "-" ? -double.INFINITY : double.INFINITY;
-      return new ScalarNode(Tag.yaml("float"), value: value);
+      return new ScalarNode(Tag.yaml("float"), span, value: value);
     }
 
     match = new RegExp(r"^\.(nan|NaN|NAN)$").firstMatch(content);
     if (match != null) {
-      return new ScalarNode(Tag.yaml("float"), value: double.NAN);
+      return new ScalarNode(Tag.yaml("float"), span, value: double.NAN);
     }
 
     return null;
   }
 
   /// Parses a string scalar.
-  ScalarNode parseString(String content) =>
-    new ScalarNode(Tag.yaml("str"), value: content);
+  ScalarNode parseString(String content, Span span) =>
+    new ScalarNode(Tag.yaml("str"), span, value: content);
 }