private ParseResults <TSource> ParseNodes(CommandNode <TSource> node, StringReader originalReader, CommandContextBuilder <TSource> contextSoFar)
{
var source = contextSoFar.Source;
IDictionary <CommandNode <TSource>, CommandSyntaxException> errors = null;
List <ParseResults <TSource> > potentials = null;
var cursor = originalReader.Cursor;
foreach (var child in node.GetRelevantNodes(originalReader))
{
if (!child.CanUse(source))
{
continue;
}
var context = contextSoFar.Copy();
var reader = new StringReader(originalReader);
try
{
try
{
child.Parse(reader, context);
}
catch (CommandSyntaxException)
{
throw;
}
catch (Exception ex)
{
throw CommandSyntaxException.BuiltInExceptions.DispatcherParseException().CreateWithContext(reader, ex.Message);
}
if (reader.CanRead())
{
if (reader.Peek() != ArgumentSeparatorChar)
{
throw CommandSyntaxException.BuiltInExceptions.DispatcherExpectedArgumentSeparator().CreateWithContext(reader);
}
}
}
catch (CommandSyntaxException ex)
{
if (errors == null)
{
errors = new Dictionary <CommandNode <TSource>, CommandSyntaxException>();
}
errors.Add(child, ex);
reader.Cursor = cursor;
continue;
}
context.WithCommand(child.Command);
if (reader.CanRead(child.Redirect == null ? 2 : 1))
{
reader.Skip();
if (child.Redirect != null)
{
var childContext = new CommandContextBuilder <TSource>(this, source, child.Redirect, reader.Cursor);
var parse = ParseNodes(child.Redirect, reader, childContext);
context.WithChild(parse.Context);
return(new ParseResults <TSource>(context, parse.Reader, parse.Exceptions));
}
else
{
var parse = ParseNodes(child, reader, context);
if (potentials == null)
{
potentials = new List <ParseResults <TSource> >(1);
}
potentials.Add(parse);
}
}
else
{
if (potentials == null)
{
potentials = new List <ParseResults <TSource> >(1);
}
potentials.Add(new ParseResults <TSource>(context, reader, new Dictionary <CommandNode <TSource>, CommandSyntaxException>()));
}
}
if (potentials != null)
{
if (potentials.Count > 1)
{
potentials.Sort((a, b) =>
{
if (!a.Reader.CanRead() && b.Reader.CanRead())
{
return(-1);
}
if (a.Reader.CanRead() && !b.Reader.CanRead())
{
return(1);
}
if (a.Exceptions.Count == 0 && b.Exceptions.Count > 0)
{
return(-1);
}
if (a.Exceptions.Count > 0 && b.Exceptions.Count == 0)
{
return(1);
}
return(0);
});
}
return(potentials[0]);
}
return(new ParseResults <TSource>(contextSoFar, originalReader, errors ?? new Dictionary <CommandNode <TSource>, CommandSyntaxException>()));
}