[Haskell-cafe] GetOpt

[Tomasz Zielonka]

On Tue, May 02, 2006 at 02:27:28PM +0200, Mirko Rahn wrote:
> But how to handle dependencies between options using this technique? I 
> can image two solutions:
> 1: Every dependency 'a implies b' has to be checked in both functions, 
> the one for a and the one for b.
> 2: An order for the actions has to be specified, maybe by decorating the 
> option list with priorities.
3: Handle some (not all) options in a sum-type fashion

> In contrast the sum-type technique first reads all options and then 
> post-processes the complete set. Here the order of options on the 
> commandline has no impact on the final result.

I forgot to show that you can still use old style option handling for
some options. This way you can gradually move from sum-type style to
product-type style.

Best regards
Tomasz