From 98be3213152ccec134da3e7856b8096beafcc6d8 Mon Sep 17 00:00:00 2001 From: Paul Phillips Date: Wed, 6 May 2009 15:38:18 +0000 Subject: Added NoSuccess extractor to combinator lib. --- .../scala/util/parsing/combinator/Parsers.scala | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) (limited to 'src/library') diff --git a/src/library/scala/util/parsing/combinator/Parsers.scala b/src/library/scala/util/parsing/combinator/Parsers.scala index 29fbbebc28..b2c72153fe 100644 --- a/src/library/scala/util/parsing/combinator/Parsers.scala +++ b/src/library/scala/util/parsing/combinator/Parsers.scala @@ -153,6 +153,17 @@ trait Parsers { def get: Nothing = error("No result when parsing failed") } + /** An extractor so NoSuccess(msg, next) can be used in matches + * Note: case class inheritance is currently sketchy and may be + * deprecated, so an explicit extractor is better. + */ + object NoSuccess { + def unapply[T](x: ParseResult[T]) = x match { + case Failure(msg, next) => Some(msg, next) + case Error(msg, next) => Some(msg, next) + case _ => None + } + } /** The failure case of ParseResult: contains an error-message and the remaining input. * Parsing will back-track when a failure occurs. @@ -304,8 +315,7 @@ trait Parsers { case (s1 @ Success(_, _), _) => s1 case (_, s2 @ Success(_, _)) => s2 case (e1 @ Error(_, _), _) => e1 - case (f1 @ Failure(_, next1), f2 @ Failure(_, next2)) => if (next2.pos < next1.pos) f1 else f2 - case (f1 @ Failure(_, next1), e2 @ Error(_, next2)) => if (next2.pos < next1.pos) f1 else e2 + case (f1 @ Failure(_, next1), ns2 @ NoSuccess(_, next2)) => if (next2.pos < next1.pos) f1 else ns2 } } override def toString = "|||" @@ -699,9 +709,8 @@ trait Parsers { */ def not[T](p: => Parser[T]): Parser[Unit] = Parser { in => p(in) match { - case s @ Success(_, _) => Failure("Expected failure", in) - case e @ Error(_, _) => Success((), in) - case f @ Failure(msg, next) => Success((), in) + case Success(_, _) => Failure("Expected failure", in) + case _ => Success((), in) } } -- cgit v1.2.3