ghc-mod interactive: lint problem

[lemoce]

Hello guys,

I am facing strange problem on ghc-mod. When I ran this command with no error:

$ ghc-mod lint -h --ignore='Use list comprehension' file.hs
$ echo $?
0

But, I need to run in legacy-interactive, so:

$ ghc-mod legacy-interactive
lint -h --ignore='Use list comprehension' redo.hs
NG Invalid argument `comprehension''\n\nUsage:  leandro@leandro-desktop:~/workspaces/haskell/redo-ep07$

And, I tried:

workspaces/haskell/redo-ep07$ ghc-mod legacy-interactive
lint -h [] redo.hs
redo.hs:69:41: Suggestion: Use list comprehensionFound:  if hasExtension target then replaceBaseName target "default" ++ ".do"] else []Why not:  [replaceBaseName target "default" ++ .do" | hasExtension target]
OK
lint -h ["-i \"Use list comprehension\""] redo.hs
NG Invalid argument `list'\n\nUsage:  leandro@leandro-desktop:~/workspaces/haskeve/redo-ep07$ ghc-mod legacy-interactiv

And, I also tried from ghc-modi

leandro@leandro-desktop:~/workspaces/haskell/redo-ep07$ ghc-mod legacy-interactive
lint ["--ignore=Use camelCase", "--ignore=Eta reduce"] redo.hs
NG Invalid argument `camelCase",'\n\nUsage:  leandro@leandro-desktop:~/workspaces/haskell/redo-ep07$

ghc-mod version

leandro@leandro-desktop:~/workspaces/haskell/redo-ep07$ ghc-mod --version
ghc-mod version 5.7.0.0 compiled by GHC 8.0.2

hlint version

leandro@leandro-desktop:~/workspaces/haskell/redo-ep07$ hlint -V
HLint v1.9.41, (C) Neil Mitchell 2006-2016

Is there some configuration to make?

[DanielG]

You're venturing into some dark corners here, try this:

printf 'ascii-escape lint -h\x02--ignore=Use list comprehension\x03 Setup.hs\n\n' | ghc-mod legacy-interactive

Those two escaped ASCII control sequences are "\STX" and "\ETX" (in Haskell string syntax) respectively. Those two characters basically behave like quotes here but they don't nest. I don't recall why exactly we went for that instead of implementing normal shell escaping rules IIRC just because it was simpler.

This only appeared in v5.5.0.0 before that we didn't have a mechanism for spaces in legacy-interactive.

[lemoce]

Thanks for reply, @DanielG .

I am using with Emacs. There is a elisp source code ghc-check.el, which implements the function

(defun ghc-check-send ()
  (let ((file (buffer-file-name)))
    (if ghc-check-command
    (let ((opts (ghc-haskell-list-of-string ghc-hlint-options)))
      (if opts
          (format "lint %s %s\n" opts file)
        (format "lint %s\n" file)))
      (format "check %s\n" file))))

I think this function formats command for ghc-mod interactive. Is it correct?

[DanielG]

It is entirely possible that we didn't get around to patching that into the elisp bits yet. Those changes were for Atom (ide-haskell) really. So if you want that in Emacs it should be reasonably easy to fix since you already found the right function and all. Patches welcome and what have you :)

[lemoce]

I will try make a patch. I was checking the ground to see where I am stepping. =)

[lemoce]

0001-Correction-on-formatted-string-for-Emacs-ghc-lint.patch.txt

I dont know if the correct way. I tried to make a pull request, but I am not allawed.

[DanielG]

That's strange. Did you fork the repo or try to push to this one?

[lemoce]

yeap, but I am not familiar with git.

[DanielG]

Maybe you can quickly read through this Pull Request Tutorial?

[lemoce]

Thanks @DanielG

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