Debugger triggered on "match c of", a typo for "case c of"

[mcandre]

As a Haskell newbie, I want haskell-mode to behave more gracefully when I make a typo, like match c of instead of case c of. Currently, the debugger triggers on such parse errors.

[ivan-m]

Is this for indentation? Or when you load it into ghci?

[mcandre]

Indentation, no GHCi used.

[ivan-m]

Which indentation mode are you using? Can you provide the complete error for it?

[mcandre]

Here is my .emacs configuration:

https://github.com/mcandre/dotfiles/blob/master/.emacs

[ivan-m]

Pinging @gracjan and @kuribas (especially since the new indentation mode was merged in recently).

@mcandre are you installing haskell-mode via package.el or a distro package? Do you know what version it is?

[mcandre]

I load haskell-mode via use-package, install haskell-mode via Emacs Cask, source haskell-mode from MELPA, and I'm using the latest version, 20150423.710.

[ivan-m]

Yeah, so it is to do with the new version of haskell-indentation (and thus I can't really help you with it :p)

[mcandre]

So haskell-mode maintains haskell-indentation, right? Could we fix the bug in haskell-indentation?

[gracjan]

@mcandre: haskell-indentation uses usual elisp throw/catch mechanism to do deep unwinding. This is normal, what is not normal is that it should not trigger debugger, even if (debug-on-error t) is set.

Since you are the kind of person that has (debug-on-error t) you seem to have skill and knowledge to find out why catch/throw is triggering debugger. It should not.

Also note that MELPA comes in two variants, melpa and melpa-stable. The second one is supposed to be less bleeding edge than the first one. Instructions for both are in our https://github.com/haskell/haskell-mode/blob/master/README.md file.

[gracjan]

Here is the place:

https://github.com/haskell/haskell-mode/blob/master/haskell-indentation.el#L561

[kuribas]

hm, this is the same bug as in #483 I have a fix in my own haskell-indentation.el, but it is quite
out of sync with master. I should have a fix when I can get myself out the github mess...

[gracjan]

Which repo? I see nothing here: https://github.com/kuribas/haskell-mode And nothing here: https://github.com/kuribas/hi2 @kuribas, I tried to send you an email but no result. Which inbox do you respond to?

[kuribas]

In my local repo, sorry... You can send mail to my resonata inbox.

[mcandre]

@kuribas A fix you say? Please merge :)

I'm actually new to Emacs Lisp; The only reason I turned on debug-on-error is to produce better bug reports, lol!

[gracjan]

Haha, well, we need to built some mechanism for bug reporting tailored for haskell-mode. debug-on-error sure isn't one of those :)

[gracjan]

Thinking about this more I come to reason that haskell indentation should have a much more permissive parser. It should care only about of being a keyword, case can be treated as ordinary identifier, so it will not bail out when it see match. It won't care.

[gracjan]

This is no longer bailing out with parse error.