Re: Bug: Babel Haskell mode [8.0.3 (8.0.3-30-g56b864-elpa @ /Users/ix/.emacs.d/elpa/org-20130610/)]

[Eric Schulte <schulte.eric@gmail.com>]

Simon Beaumont <simon@datalligator.com> writes:

> Well that's really odd: I modded the paths in init.el and did the following:
>
> emacs -Q -l init.el foo.org
>
> When I eval'ed the code block in foo.org (twice) I still get message:
> "Code block returned no value" I've attached the inferior haskell
> buffer and all relevant files.
>
> (add-to-list 'load-path "~/.emacs.d/elpa/haskell-mode-20130610.152")

I thought maybe it could be a difference between our haskell modes, so I
switched to the latest available through my elpa (haskell-mode-13.6),
and I still see the correct behavior.

> GHClet fac n = product [1..n]
> [(x,fac x) | x <- [0..11]]
> "org-babel-haskell-eoe"
> i, version 7.6.3: http://www.haskell.org/ghc/  :? for help
> Loading package ghc-prim ... linking ... done.
> Loading package integer-gmp ... linking ... done.
> Loading package base ... linking ... done.
>> [(0,1),(1,1),(2,2),(3,6),(4,24),(5,120),(6,720),(7,5040),(8,40320),(9,362880),(10,3628800),(11,39916800)]
>> "org-babel-haskell-eoe"
>> let fac n = product [1..n]
> [(x,fac x) | x <- [0..11]]
> "org-babel-haskell-eoe"
>> [(0,1),(1,1),(2,2),(3,6),(4,24),(5,120),(6,720),(7,5040),(8,40320),(9,362880),(10,3628800),(11,39916800)]
>> "org-babel-haskell-eoe"
>

My *haskell* buffer looks different then yours.  Namely I have
"Prelude>" where as you just have ">".  I don't know if this is
significant.  Maybe you've customized your ghci prompts in such a way
that the comint functions can no longer recognize where output begins?

,----
| GHCi, version 7.6.3: http://www.haskell.org/ghc/  :? for help
| Loading package ghc-prim ... let fac n = product [1..n]
| [(x,fac x) | x <- [0..11]]
| "org-babel-haskell-eoe"
| linking ... done.
| Loading package integer-gmp ... linking ... done.
| Loading package base ... linking ... done.
| Prelude> Prelude> [(0,1),(1,1),(2,2),(3,6),(4,24),(5,120),(6,720),(7,5040),(8,40320),(9,362880),(10,3628800),(11,39916800)]
| Prelude> "org-babel-haskell-eoe"
| Prelude> let fac n = product [1..n]
| [(x,fac x) | x <- [0..11]]
| "org-babel-haskell-eoe"
| Prelude> [(0,1),(1,1),(2,2),(3,6),(4,24),(5,120),(6,720),(7,5040),(8,40320),(9,362880),(10,3628800),(11,39916800)]
| Prelude> "org-babel-haskell-eoe"
| Prelude> 
`----

I'm not sure what else this could be.  One option would be to instrument
`org-babel-execute:haskell' or `org-babel-comint-with-output' with
edebug, and then step through evaluation to see if you can pinpoint
where the problem lies.

Hope this helps,

-- 
Eric Schulte
http://cs.unm.edu/~eschulte