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You can reach the person managing the list at beginners-ow...@haskell.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Beginners digest..." Today's Topics: 1. Re: a problem with happy ABCParser example (Stephen Tetley) 2. Re: a problem with happy ABCParser example (kak dod) 3. functional parser type error (felipe zapata) ---------------------------------------------------------------------- Message: 1 Date: Mon, 2 Apr 2012 18:08:25 +0100 From: Stephen Tetley <stephen.tet...@gmail.com> Subject: Re: [Haskell-beginners] a problem with happy ABCParser example To: kak dod <kak.dod2...@gmail.com> Cc: beginners@haskell.org Message-ID: <CAB2TPRAsj9kssC05oce9TkmdmDfbx-0VsUzviqVG=4gpxbh...@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Have you tried > parse "abc\n" The grammar looks as though it mandates a terminating newline. ------------------------------ Message: 2 Date: Mon, 2 Apr 2012 23:13:52 +0530 From: kak dod <kak.dod2...@gmail.com> Subject: Re: [Haskell-beginners] a problem with happy ABCParser example To: Stephen Tetley <stephen.tet...@gmail.com> Cc: beginners@haskell.org Message-ID: <CAJ4=wneu66v27odehsxpucfzh4sog7gb+ughure57153mgu...@mail.gmail.com> Content-Type: text/plain; charset="iso-8859-1" thanks a lot ... really overlooked it foolishly ... On Mon, Apr 2, 2012 at 10:38 PM, Stephen Tetley <stephen.tet...@gmail.com>wrote: > Have you tried > > > parse "abc\n" > > The grammar looks as though it mandates a terminating newline. > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.haskell.org/pipermail/beginners/attachments/20120402/64a7c2f9/attachment-0001.htm> ------------------------------ Message: 3 Date: Mon, 2 Apr 2012 21:58:31 +0100 From: felipe zapata <tifonza...@gmail.com> Subject: [Haskell-beginners] functional parser type error To: beginners@haskell.org Message-ID: <CA+AeLgTUD=xzdvejr4h63isejx1g7sandchzvucqbb2c-vy...@mail.gmail.com> Content-Type: text/plain; charset="iso-8859-1" Hi. I'm Following the book of Programming in haskell written by Graham Hutton. In Chapter number 8 there is a discussion about functional parsers and it is defined a functional Parser item and some basic parsers as follow *success :: a -> Parser a* *success v = \ inp -> [(v,inp)]* *failure :: Parser a* *failure = \inp -> [ ]* *item :: Parser Char* *item = \inp -> case inp of* *[ ] -> [ ]* *(x:xs) -> [(x,xs)]* Based on this parser it is defined a* *new parser called *sat p* *sat :: (Char -> Bool ) -> Parser Char* *sat p = do x <- item* *if p x then success x else failure* as result, this error appears *Couldn't match expected type `Char'* *with actual type `[(Char, String)]'* *In the first argument of `p', namely `x'* *In the expression: p x* *In the expression: if p x then success x else failure* Can you help me ? Greets, Felipe -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.haskell.org/pipermail/beginners/attachments/20120402/332803c2/attachment-0001.htm> ------------------------------ _______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners End of Beginners Digest, Vol 46, Issue 2 ****************************************