Well another possible solution is to wrap the code blocks in :{ xxx :} in (defun org-babel-execute:haskell (body params) -- ob-haskell.el Immanuel
On Thu, Dec 10, 2020 at 6:21 PM Lawrence Bottorff <borg...@gmail.com> wrote: > > I see your point, i.e., compiled, multi-file projects are not really meant > for the REPL-dominant world of org-mode babel. Babel's sweet-spot would be > the interpreted world, the very best probably a Lisp language. Still, the > ability to add code to a running REPL should be possible. As I mentioned, SML > is a sibling of Haskell and its babel implementation worked fine for me as I > worked through an SML course. So yes, this appears to be a Haskell REPL > issue. I'm just a beginner with Haskell, and all my intro texts start you out > using the ghci REPL interactively. But then they switch you over to a text > file compiled in the REPL with :l myfile.hs . . . no explanation as to why > you can't just continue with the REPL putting the program in line-by-line. > The fact that I can use the :set +m to include multiple lines of code, but > cannot do a type definition is rather bizarre, though. This is a decision > Haskell made with their REPL and babel really can't do much about it, I > suppose. The Haskell .lhs literate option is interesting. Yes, I'd like to > see your tangle option, please. > > On Thu, Dec 10, 2020 at 4:28 AM Immanuel Litzroth > <immanuel.litzr...@gmail.com> wrote: >> >> I don't think org-babel is a good fit for compiled languages. If the >> idea is to just take 1 snippet, >> and "execute" that it means that to have a consistent whole you'd need >> to put all the modules of >> your program into that snippet (already impossible in Haskell, you can >> have only 1 module per file), >> compile that, run the resulting binary. Or org mode would have to have >> some idea of what needs to >> be retangled & rebuilt. >> I think that using org-babel for compiled, multifile languages will >> only work in very simple cases -- and >> even then.. -- but will lead to problems very soon. >> Immanuel >> >> On Thu, Dec 10, 2020 at 4:21 AM Lawrence Bottorff <borg...@gmail.com> wrote: >> > >> > I'm looking into Haskell (latest ghci) again on org-mode. This >> > >> > #+begin_src haskell :results verbatim :exports both >> > :set +m >> > doubleSmallNumber x = if x > 100 >> > then x >> > else x*2 >> > #+end_src >> > >> > works, but still the :set +m is necessary for it to see the whole. But this >> > >> > #+begin_src haskell :results verbatim :exports both >> > :set +m >> > factorial :: Int -> Int >> > factorial 0 = 1 >> > factorial n = n * factorial (n - 1) >> > #+end_src >> > >> > results in this on the REPL side: >> > >> > Prelude> :set +m >> > factorial :: Int -> Int >> > factorial 0 = 1 >> > factorial n = n * factorial (n - 1) >> > "org-babel-haskell-eoe" >> > Prelude> >> > <interactive>:26:1-23: error: >> > • No instance for (Show (Int -> Int)) arising from a use of ‘print’ >> > (maybe you haven't applied a function to enough arguments?) >> > • In a stmt of an interactive GHCi command: print it >> > Prelude> Prelude> Prelude> "org-babel-haskell-eoe" >> > >> > which is the same behavior if I try to feed the program into the REPL one >> > line at a time, i.e., >> > >> > Prelude> factorial :: Int -> Int >> > >> > <interactive>:40:1-23: error: >> > • No instance for (Show (Int -> Int)) arising from a use of ‘print’ >> > (maybe you haven't applied a function to enough arguments?) >> > • In a stmt of an interactive GHCi command: print it >> > >> > So the :set +m trick (take multiple lines) doesn't help here. Obviously, >> > Haskell is not ready to be used with Babel. Can it be fixed? BTW, this >> > does work with the regular ghci REPL and haskell-mode. If it helps, >> > Standard ML, which has very similar syntax (it was Haskell's parent), >> > works fine. >> > >> > LB >> >> >> >> -- >> -- Researching the dual problem of finding the function that has a >> given point as fixpoint. -- -- Researching the dual problem of finding the function that has a given point as fixpoint.