[Haskell-cafe] Re: [Parsec] A combinator to match between M and N times?

29 Aug 2006


      On Tue, Aug 29, 2006 at 03:11:09PM +0200,
 Tomasz Zielonka  wrote 
 a message of 28 lines which said:
...
How about this?
It works fine, many thanks. Here is the version rewritten according to
my taste:

import Text.ParserCombinators.Parsec
import Data.Maybe (catMaybes)

countBetween m n p 
     | n < m     = error "First bound must be lower or equal than second bound"
     | otherwise = do
        xs <- count m p
        ys <- count (n - m) ((option Nothing) (do
            y <- p
            return (Just y)))
        return (xs ++ catMaybes ys)

[Haskell-cafe] Re: [Parsec] A combinator to match between M and N times?

Stephane Bortzmeyer