/// <summary>
/// Parses the node represented by the next event in <paramref name="events" />.
/// </summary>
/// <param name="events">The events.</param>
/// <param name="state">The state.</param>
/// <returns>Returns the node that has been parsed.</returns>
static internal YamlNode ParseNode(EventReader events, DocumentLoadingState state)
{
if (events.Accept <Scalar>())
{
return(new YamlScalarNode(events, state));
}
if (events.Accept <SequenceStart>())
{
return(new YamlSequenceNode(events, state));
}
if (events.Accept <MappingStart>())
{
return(new YamlMappingNode(events, state));
}
if (events.Accept <AnchorAlias>())
{
AnchorAlias alias = events.Expect <AnchorAlias>();
return(state.GetNode(alias.Value, false, alias.Start, alias.End) ?? new YamlAliasNode(alias.Value));
}
throw new ArgumentException("The current event is of an unsupported type.", "events");
}
/// <summary>
/// Initializes a new instance of the <see cref="YamlSequenceNode"/> class.
/// </summary>
/// <param name="events">The events.</param>
/// <param name="state">The state.</param>
internal YamlSequenceNode(EventReader events, DocumentLoadingState state)
{
SequenceStart sequence = events.Expect <SequenceStart>();
Load(sequence, state);
Style = sequence.Style;
bool hasUnresolvedAliases = false;
while (!events.Accept <SequenceEnd>())
{
YamlNode child = ParseNode(events, state);
children.Add(child);
hasUnresolvedAliases |= child is YamlAliasNode;
}
if (hasUnresolvedAliases)
{
state.AddNodeWithUnresolvedAliases(this);
}
#if DEBUG
else
{
foreach (var child in children)
{
if (child is YamlAliasNode)
{
throw new InvalidOperationException("Error in alias resolution.");
}
}
}
#endif
events.Expect <SequenceEnd>();
}
/// <summary>
/// Initializes a new instance of the <see cref="YamlDocument"/> class.
/// </summary>
/// <param name="events">The events.</param>
internal YamlDocument(EventReader events)
{
DocumentLoadingState state = new DocumentLoadingState();
events.Expect <DocumentStart>();
while (!events.Accept <DocumentEnd>())
{
Debug.Assert(RootNode == null);
RootNode = YamlNode.ParseNode(events, state);
if (RootNode is YamlAliasNode)
{
throw new YamlException();
}
}
state.ResolveAliases();
#if DEBUG
foreach (var node in AllNodes)
{
if (node is YamlAliasNode)
{
throw new InvalidOperationException("Error in alias resolution.");
}
}
#endif
events.Expect <DocumentEnd>();
}
/// <summary>
/// Initializes a new instance of the <see cref="YamlScalarNode"/> class.
/// </summary>
/// <param name="events">The events.</param>
/// <param name="state">The state.</param>
internal YamlScalarNode(EventReader events, DocumentLoadingState state)
{
Scalar scalar = events.Expect <Scalar>();
Load(scalar, state);
Value = scalar.Value;
Style = scalar.Style;
}
/// <summary>
/// Resolves the aliases that could not be resolved when the node was created.
/// </summary>
/// <param name="state">The state of the document.</param>
internal override void ResolveAliases(DocumentLoadingState state)
{
for (int i = 0; i < children.Count; ++i)
{
if (children[i] is YamlAliasNode)
{
children[i] = state.GetNode(children[i].Anchor, true, children[i].Start, children[i].End);
}
}
}
/// <summary>
/// Loads the specified event.
/// </summary>
/// <param name="yamlEvent">The event.</param>
/// <param name="state">The state of the document.</param>
internal void Load(NodeEvent yamlEvent, DocumentLoadingState state)
{
Tag = yamlEvent.Tag;
if (yamlEvent.Anchor != null)
{
Anchor = yamlEvent.Anchor;
state.AddAnchor(this);
}
Start = yamlEvent.Start;
End = yamlEvent.End;
}
/// <summary>
/// Initializes a new instance of the <see cref="YamlMappingNode"/> class.
/// </summary>
/// <param name="events">The events.</param>
/// <param name="state">The state.</param>
internal YamlMappingNode(EventReader events, DocumentLoadingState state)
{
MappingStart mapping = events.Expect <MappingStart>();
Load(mapping, state);
Style = mapping.Style;
bool hasUnresolvedAliases = false;
while (!events.Accept <MappingEnd>())
{
YamlNode key = ParseNode(events, state);
YamlNode value = ParseNode(events, state);
try
{
children.Add(key, value);
}
catch (ArgumentException err)
{
throw new YamlException(key.Start, key.End, "Duplicate key", err);
}
hasUnresolvedAliases |= key is YamlAliasNode || value is YamlAliasNode;
}
if (hasUnresolvedAliases)
{
state.AddNodeWithUnresolvedAliases(this);
}
#if DEBUG
else
{
foreach (var child in children)
{
if (child.Key is YamlAliasNode)
{
throw new InvalidOperationException("Error in alias resolution.");
}
if (child.Value is YamlAliasNode)
{
throw new InvalidOperationException("Error in alias resolution.");
}
}
}
#endif
events.Expect <MappingEnd>();
}
/// <summary>
/// Resolves the aliases that could not be resolved when the node was created.
/// </summary>
/// <param name="state">The state of the document.</param>
internal override void ResolveAliases(DocumentLoadingState state)
{
Dictionary <YamlNode, YamlNode> keysToUpdate = null;
Dictionary <YamlNode, YamlNode> valuesToUpdate = null;
foreach (var entry in children)
{
if (entry.Key is YamlAliasNode)
{
if (keysToUpdate == null)
{
keysToUpdate = new Dictionary <YamlNode, YamlNode>();
}
keysToUpdate.Add(entry.Key, state.GetNode(entry.Key.Anchor, true, entry.Key.Start, entry.Key.End));
}
if (entry.Value is YamlAliasNode)
{
if (valuesToUpdate == null)
{
valuesToUpdate = new Dictionary <YamlNode, YamlNode>();
}
valuesToUpdate.Add(entry.Key, state.GetNode(entry.Value.Anchor, true, entry.Value.Start, entry.Value.End));
}
}
if (valuesToUpdate != null)
{
foreach (var entry in valuesToUpdate)
{
children[entry.Key] = entry.Value;
}
}
if (keysToUpdate != null)
{
foreach (var entry in keysToUpdate)
{
YamlNode value = children[entry.Key];
children.Remove(entry.Key);
children.Add(entry.Value, value);
}
}
}
/// <summary> /// Resolves the aliases that could not be resolved when the node was created. /// </summary> /// <param name="state">The state of the document.</param> internal abstract void ResolveAliases(DocumentLoadingState state);
/// <summary>
/// Resolves the aliases that could not be resolved when the node was created.
/// </summary>
/// <param name="state">The state of the document.</param>
internal override void ResolveAliases(DocumentLoadingState state)
{
throw new NotSupportedException("Resolving an alias on an alias node does not make sense");
}