[Haskell-cafe] Re: Parsec beginners problem

Al Falloon afalloon at synopsys.com
Fri Apr 27 12:58:15 EDT 2007

Jim Burton wrote:
> After posting I realised the difference between parsing "(a)" <|> "(b)" and
> parsing "a" <|> "aa" ... so Parsec doesn't do the latter well or at all?

It should do (try "aa") <|> "a" just fine. If you mean a general 
sequence of "a"s then (many1 (char "a")) should do.

The Morse Code problem is a little harder though. To handle the 
ambiguity you may need to simultaneously consider possible parses of the 
dots and dashes. I suggest you look into using the List monad. As for 
the actual parsing of the dots and dashes, Parsec may be overkill.

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