Uncommenting in Elm only works when comment characters are at beginning of line

[joncol]

Hi! Thanks for the package!

When using this with Elm code I run into the problem that uncommenting doesn't work, unless the -- characters (that are used for comments in this language) are immediately at the beginning of a line. For instance, if commenting out something that is indented (4 spaces), the result will be something like:

    -- div [] [text "hello, world"]

When then trying to uncomment you instead get a double comment:

    -- -- div [] [text "hello, world"]

Any help with resolving this would be greatly appreciated!

[redguardtoo]

What's the major-mode for elm?

[joncol]

What's the major-mode for elm?

It's this one: https://melpa.org/#/elm-mode

[redguardtoo]

Can't reproduce the issue with elm v0.21.0 from stable.melpa.org. evil-nerd-commentter only calls builtin API without any extra setup on comment syntax. Looks it's elm-mode problem.

[joncol]

OK, I ran with a completely clean setup, only evil, evil-nerd-commenter, and elm-mode, and then the problem did not occur for me either. Let me try and figure out the root of the problem, and I'll close this with a comment.

[joncol]

OK, very strange: when I add the following to my setup, I get the problem described in this issue:

(use-package ox-hugo
  :after ox)

ox-hugo is a package used to be able to export to Hugo static blogs fromorg-mode. That's some spooky action at a distance from the looks of it. I don't know if you want me to close this issue, or if you want to dig deeper?

[kaushalmodi]

@joncol ox-hugo does not affect your major mode and related things like commenting/uncommenting in any way (and especially not outside an org-mode buffer!). It simply provides you with an Org exporter backend. I'd be really surprised if ox-hugo is actually what's causing this.

[redguardtoo]

OK, very strange: when I add the following to my setup, I get the problem described in this issue:

(use-package ox-hugo
  :after ox)

ox-hugo is a package used to be able to export to Hugo static blogs fromorg-mode. That's some spooky action at a distance from the looks of it. I don't know if you want me to close this issue, or if you want to dig deeper?

You can use emacs27 and elm-mode from stable.melpa.org.

Raise a issue to elm-mode team and give them details (Emacs version, elm-mode version, steps to reproduce).

[joncol]

@joncol ox-hugo does not affect your major mode and related things like commenting/uncommenting in any way (and especially not outside an org-mode buffer!). It simply provides you with an Org exporter backend. I'd be really surprised if ox-hugo is actually what's causing this.

Hi (and thanks for making ox-hugo!), yes it seems very weird. I have a pretty messy org-mode setup, so it could be something else that's interacting in a bad way with the commenting functionality. But for now, my problem is solved by disabling ox-hugo. Which is annoying, but these days I do more elm commenting than blogging anyways so... If I find the time, I could try and narrow it down further to create a minimal example that demonstrates the failure.

[redguardtoo]

Sure.

The comment syntax is controlled by a few flags in newcomment.el, likecomment-start, comment-start-skip, comment-end, comment-end-skip, comment-add ....

elm-mode developers might need this information for debugging.

[joncol]

Hmm, think I found the actual source of the problem now:

              ;; do not treat "-" as a word separator
              (modify-syntax-entry ?- "w")

I think this is what causes the problems. Do you think it's possible @redguardtoo ?

[redguardtoo]

sytnax table is usually set up by major mode. It's better ask the major mode author to fix the issue for you.