Re: ob-haskell

[Ken Mankoff]

Hi Lawrence,

This isn't a method for official language support, but I've had success with 
entirely unsupported REPLs and ob-screen. A .screenrc can launch the REPL, and 
then Org ob-screen just sends each line to the buffer. It works OK for me.

  -k.

On 2021-01-02 at 13:44 -08, Lawrence Bottorff <borgauf@gmail.com> wrote...
> I recently wimped out of trying to update ob-haskell as an official
> maintainer, but I'd eventually like to get back to it -- *after *I get
> some base understanding of what Haskell is (Zeno's paradox-land?) and
> how the ghci works. Basically, the ghci is what it is -- tautological,
> but true. And that means when ob-haskell does nothing but dump the
> contents of a babel code block into ghci, it's no better than if the
> user had typed in into the REPL line-by-line. A quick run-down:
>
> :set +m supposedly alerts ghci that a multi-line expression is coming, will
> come; but typically, it doesn't infer this very well.
>
> Enclosing code in :{ ... :} is fairly good -- again you can type this in at
> the REPL prompt and see how it works -- however, there are gotchas.
>
> a plain block:
>
> #+begin_src haskell
> ...code...
> #+end_src
>
> is okay when you only have a one-liner to evaluate. But again, ob-haskell
> seems to do nothing but take the block contents and dump it to the ghci
> REPL as though the user had typed it in line-by-line, Enter, Enter...
>
> What would be nice is if a C-c C-c inside a block could somehow act as
> though the ghci were being sent a regular  *.hs buffer in haskell-mode --
> and that, of course, cumulatively. C-' creates a decent haskell-mode
> environment, BTW, so some form of a babel block to haskell-mode connection
> does exist....
>
> So am I on the right track? It's obvious at this point raw dumps into the
> REPL aren't optimal, i.e., are fraught. What is, e.g., geiser&Scheme doing
> that ob-haskell isn't?
>
> LB
>
> PS: Eventually, I'll try to glean some hints from the Jupyter Haskell
> <https://github.com/gibiansky/IHaskell> effort.
>
> PPS: GHCI User's Guide
> <https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/ghci.html>
> doesn't
> really tell me anything other than yes, ob-haskell is raw-dumping into an
> environment that isn't designed to play nice with babel.