public override ParseTree Parse(Lexer lexer, ParserState state)
{
int start = lexer.Position;
if (type == null)
{
throw new Exception();
}
if (state.RuntimeState.Runtime.TraceParser)
{
state.RuntimeState.Runtime.ParseTrace.Enter(this,
lexer.CurrentSource(),
"User defined node " + TypeNames.GetName(type));
}
object instance = NewNode.New(state.RuntimeState, type, null);
object parseMethod = MemberNode.GetMember(instance, "Parse", true);
object result = CallNode.Call(state.RuntimeState, parseMethod,
new object[] { lexer });
if (result == null)
{
result = ParseTree.Yes;
}
else if (result is bool)
{
if ((bool)result)
{
result = ParseTree.Yes;
}
else
{
result = ParseTree.No;
}
}
if (state.RuntimeState.Runtime.TraceParser)
{
if (result == ParseTree.No)
{
state.RuntimeState.Runtime.ParseTrace.No(this,
lexer.SourceFrom(start));
}
else
{
state.RuntimeState.Runtime.ParseTrace.Yes(this,
lexer.SourceFrom(start));
}
}
return((ParseTree)result);
}