/// <summary>
/// A label for the parser
/// </summary>
/// <param name="expected">What was expected</param>
public static Parser <T> label <T>(this Parser <T> p, string expected) =>
inp =>
{
var res = p(inp);
if (res.Tag == ResultTag.Consumed)
{
return(res);
}
if (res.Reply.Tag == ReplyTag.Error)
{
return(EmptyError <T>(ParserError.Expect(inp.Pos, res.Reply.Error.Msg, expected)));
}
if (res.Reply.Error == null || res.Reply.Error.Tag == ParserErrorTag.Unknown)
{
return(res);
}
else
{
return(EmptyOK(res.Reply.Result, res.Reply.State, ParserError.Expect(inp.Pos, res.Reply.Error.Msg, expected)));
}
};