[Haskell-cafe] Picking an architecture for a Haskell web app

[Neil Mitchell]

Hi

> I'm currently in the process of attempting to write such a thing...

Good luck! Haskell needs more implementations to retain its purity and
compatibility.

>
> > What is the value of show [] ?
>
> That is indeed a difficult point. Since I want an interpreter so I can
> step through the code interactively, I was just going to make the
> interpreter *ask* me which implementation to call...

Yuk! I couldn't think of a better answer, which is what stopped me
from writing such an evaluator.


> On the other hand, parsing Haskell input is intractably hard. Whitespace
> actually matters, which makes the program to parse Haskell horrendusly
> complex. Several times I've been forced to give up due to the sheer
> complexity of it all.

Why not just reuse the standard Haskell parser? Its in Hacle (google
keyword: Hacle) amongst other places. It parses all of Haskell, and is
pretty easy to use.

Thanks

Neil