Re: Haskell code blocks

[Thomas S. Dye]

Thanks Ihor.  I don't actually use Haskell.  Earlier this year I 
attempted to complete the Org Babel language documents on Worg, 
but couldn't get the obligatory "hello world" code block to behave 
in Haskell.  I'm guessing that ob-haskell.el actually works for 
experienced Haskell programmers and was hoping someone had a 
solution to the Prelude> problem.  I'm not sure when I might get 
back to this.

All the best,
Tom

Ihor Radchenko <yantar92@posteo.net> writes:

> "Thomas S. Dye" <tsd@tsdye.online> writes:
>
> > I'm struggling to write a minimal ob-doc-haskell.org for Worg.
> >
> > I installed Haskell via Spacemacs (development branch) and the 
> > Haskell installation appears to be functioning correctly.
> >
> > The obligatory Hello World! example yields bad results.
> >
> > #+name: haskell-hello-world
> > #+begin_src haskell 
> > main :: IO () 
> > main = putStrLn  "Hello, World!"
> > main
> > #+end_src
> >
> > #+RESULTS: haskell-hello-world
> > : Prelude> Hello, World!
> >
> > I'm guessing the "Prelude>" part of the output is the prompt 
> > from 
> > the interpreter.
> >
> > I found this in ob-haskell.el:
> >
> >               (setq-local comint-prompt-regexp
> >                           (concat haskell-prompt-regexp 
> >                           "\\|^λ?> 
> >                           "))))
> >                           
> > But I couldn't find a way to modify haskell-prompt-regexp 
> > without 
> > changing the source.
> >
> > Advice welcome.
>
> I guess you can report this as a bug in Haskell-mode?
> haskell-prompt-regexp is defined there.
>
> If absolutely necessary and if you want that _your_ Haskell 
> prompt is
> different from Haskell-mode defaults, just setq 
> haskell-prompt-regexp in
> your config.


--
Thomas S. Dye
https://tsdye.online/tsdye