haskell-indentation seems to have problems with underscore

[bmktuwien]

I have currently a strange problem with haskell-indentation-mode if one of the function argument identifiers contains the _ character:

foo (Foo _) = []
foo x = go x

With the code above, if I press <tab> in the second line, then I get the message Parse error.
The problem disappears if I write (Foo foo) instead of (Foo _), but this is not a solution for me, since the compiler will generate a warning if I don't use the variable.

I am using the version: 20150323.559
(Maybe this issue is related to the issue #526)

[ivan-m]

For linkification purposes: #526 (putting it in backticks stops GitHubs automagic linkification).

[bmktuwien]

@ivan-m Thanks, my bad. I have updated my post...

[gracjan]

@bmktuwien: can you check if work on branch wip/hi2 also exposes this problem?

[bmktuwien]

@gracjan I have just checked it with hi2 ver. 20141005, and the issue is the same...

I have installed hi2 via Melpa

[gracjan]

Can you check if patch in #548 fixes your issue?

[bmktuwien]

@gracjan Yes! The patch solves the problem! Thank you so much!

[gracjan]

Good to hear! Note that this patch might have side effects. If you spot anything else unusual please report back, okay?

[bmktuwien]

Ok, will do!

[gracjan]

@bmktuwien: are you sure wip/hi2 does not solve the issue as is? On that branch there is this commit 74154cf that should basically do what you need that is treat underscore as part of identifier.

[bmktuwien]

As I mentioned in the post, I've installed the hi2 version 20141005 package via Melpa package manager and didn't install it directly from the wip/hi2 branch. And since the patch was from 15 days ago, it was surely not part of the 20141005 version. I will check it again later when I get back home from work.

[gracjan]

I see. I would ask you to specifically test out wip/hi2 branch as it has fixes on top of what is available via hi2 package from melpa.

[gracjan]

Next generation haskell-indentation mode has been merged and it is expected that this issue is fixed. Please check if your issue is resolved by that. If it is not please write a comment here or just open new request. Thanks!

[bmktuwien]

I've just updated haskell-mode via Melpa and so far so good! Everything works! Thx again and good job!