Make YamlException inherit from SpanFormatException.

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 'model.dart';
 import 'visitor.dart';
 import 'yaml_exception.dart';
 
@@ skipping 16 matching lines @@
   var _idCounter = 0;
 
   Composer(this._root);
 
   /// Runs the Composer to produce a representation graph.
   Node compose() => _root.visit(this);
 
   /// Returns the anchor to which an alias node refers.
   Node visitAlias(AliasNode alias) {
     if (!_anchors.containsKey(alias.anchor)) {
-      throw new YamlException("No anchor for alias ${alias.anchor}.");
+      throw new YamlException("No anchor for alias ${alias.anchor}.",
+          alias.span);
     }
     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));
     } else if (scalar.tag.name == "?") {
       for (var fn in [parseNull, parseBool, parseInt, parseFloat]) {
         var result = fn(scalar);
         if (result != null) return result;
       }
       return setAnchor(scalar, parseString(scalar));
     }
 
     var result = _parseByTag(scalar);
     if (result != null) return setAnchor(scalar, result);
-    throw new YamlException('Invalid literal for ${scalar.tag}: '
-        '"${scalar.content}".');
+    throw new YamlException('Invalid literal for ${scalar.tag}.',
+        scalar.span);
   }
 
   ScalarNode _parseByTag(ScalarNode scalar) {
     switch (scalar.tag.name) {
       case "null": return parseNull(scalar);
       case "bool": return parseBool(scalar);
       case "int": return parseInt(scalar);
       case "float": return parseFloat(scalar);
       case "str": return parseString(scalar);
     }
-    throw new YamlException('Undefined tag: ${scalar.tag}.');
+    throw new YamlException('Undefined tag: ${scalar.tag}.', scalar.span);
   }
 
   /// 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}.");
+      throw new YamlException("Invalid tag for sequence: ${seq.tag}.",
+          seq.span);
     }
 
     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}.");
+      throw new YamlException("Invalid tag for mapping: ${map.tag}.",
+          map.span);
     }
 
     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].
@@ skipping 69 matching lines @@
       return new ScalarNode(Tag.yaml("float"), scalar.span, value: double.NAN);
     }
 
     return null;
   }
 
   /// Parses a string scalar.
   ScalarNode parseString(ScalarNode scalar) =>
     new ScalarNode(Tag.yaml("str"), scalar.span, value: scalar.content);
 }