[Haskell-beginners] Parse string with optional entries [Parsec]

[Stefan.Lukasser-EE at infineon.com]

Hi,

I have something similar to the CSV-Parser in RWH, chapter 16.    
The problem are the possible empty cells, i.e. consecutive '\t'-Characters.


-----Original Message-----
From: Antoine Latter [mailto:aslatter at gmail.com] 
Sent: Monday, August 08, 2011 1:44 PM
To: Lukasser Stefan (IFAT IMM PSD D TEC / EE)
Cc: beginners at haskell.org
Subject: Re: [Haskell-beginners] Parse string with optional entries [Parsec]

On Mon, Aug 8, 2011 at 6:39 AM,  <Stefan.Lukasser-EE at infineon.com> wrote:
> Hi all,
>
> I'm trying to parse a string in one of the following forms using Parsec:
>
> "1\t1\t123\t456" -> desired output: [Just 1, Just 1, Just 123, Just 456]
>
> or
>
> "1\t\1\t\t456"  -> desired output: [Just 1, Just 1, Nothing, Just 456]
>
> i.e., the input is a list of numbers, separated by '\t' characters, with the possibility of missing entries.
> I'm having troubles with the backtracking in case of missing numbers. Can anybody give me a hint?
>

What do you have so far?

> Thanks in advance,
> Stefan
>
> _______________________________________________
> Beginners mailing list
> Beginners at haskell.org
> http://www.haskell.org/mailman/listinfo/beginners
>