Hi Eric, Thanks for investigating this.
You got it! The blooming prompt! As you say the comint parser expects "Prelude>" and I have customised my prompt in .ghci (also this wouldn't work with module loads like :m +Mymodule.Foo as this changes the ghci prompt). BTW if I use a unicode sequence for the prompt (like a greek lambda as a few knights of the lambda calculus do) then accept-process-output hangs! Well at least that's me fixed! Would it be possible for comint to learn the prompt by sending an empty line and then adapting? -- It would need to do this every time it sees a :command and at startup. Of course this is ghci specific. Or is the answer to write an evaluation server for ghc with a well defined client API? Then Haskell integration gets a lot easier -- this would be like slime (common-lisp) for Haskell. Might be worth an enquiry on the Haskell list as there is a Haskell API that might cover the requirement. Simon Beaumont ------------------- On 13 Jun 2013, at 06:18, Eric Schulte <schulte.e...@gmail.com> wrote: > Simon Beaumont <si...@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
