[Haskell-cafe] The Good, the Bad and the GUI

[Wojtek Narczyński]

On 13.08.2014 15:42, Heinrich Apfelmus wrote:
> Validation is mainly a question of *how* to present feedback about
> invalid data to the user -- for instance by making invalid data
> impossible to enter, or by showing errors in red and retaining the 
> last correct value, etc.

I don't even know how to capture validation rules in such a way that 
they were easy to use from the GUI layer. I suspect if they were 
captured well, whatever well might mean in this context, a functioning 
GUI could be autogenerated from those rules.

And I don't understand FRP code. I could however understand Eduardo's 
client side formlets almost immediately. Not now they work below, how to 
use them.

> Still, even for the more narrow problem of forms and input validation, 
> I don't see how you arrive at your claim that "Haskell is however not 
> great for GUIs". This seems like a problem that can be solved with a 
> traditional DSL approach, and I would be surprised if Haskell were 
> unsuitable as a host language, contrary to what your claim seems to 
> imply. Whether DSLs along these lines are already available is another 
> question. Alberto mentioned one, another one would be [1].
>

Oh, please. Haskell is great for parsing, because you can build a parser 
with e.g. parsec, attoparsec, uuparse, trifeca, in no time. Even I can 
do it. Haskell is great for concurrency, because it has lightweight 
threads, STM, and a fabulous book about it. Haskell is great for GUIs, 
because.... how about you finish this statement, I don't know how to.

-- 
Kind reagrds,
Wojtek Narczynski