Overly aggressive indenting after recent Emacs update

[giogadi]

Howdy,

I recently updated to the latest version of Emacs on Homebrew (using OSX Yosemite):

https://github.com/Homebrew/homebrew/blob/master/Library/Formula/emacs.rb

Suddenly, whenever I go to a new line using simple-indent-mode the editor always adds a 4-space indent, even in simple cases like:

foo :: Int
    foo = 1 -- auto-indent inserted here by haskell-mode

This behavior persisted even after completely nuking my emacs installation and starting over. Has anyone else experienced this issue?

[chrisdone]

I imagine the abominable electric-indent-mode has something to do with this.

[chrisdone]

Did you update to Emacs 24.4?

[giogadi]

Yes, I'm in Emacs 24.4. Aaaaaaand you're right, disabling electric-indent-mode did the trick! Abominable is right.

[purcell]

In the latest haskell-mode code electric-indent-mode is suppressed, for exactly this reason. Which version do you have?

[giogadi]

I got the version that's currently in marmalade. I guess I could switch to the melpa version, but easier thing is to just disable electric-indent, unless that's actually useful in other contexts?

[purcell]

That's extremely old (Jun 2013). You'd likely have to update your config for the newer versions to work.

electric-indent-mode is a global mode, so just (electric-indent-mode 0) at the top level to disable it completely. I personally find it helpful in major modes where the indentation is unambiguous.

If you want to disable it only in haskell-mode, then try this:

(add-hook 'haskell-mode-hook (lambda () (setq electric-indent-inhibit t)))

[giogadi]

The melpa version of haskell-mode didn't appear to have the automatic suppression of electric-indent, so I followed the tip from @purcell. Quick thing, I had to change the hook you gave me to this for it to work:

(add-hook 'haskell-mode-hook (lambda () (electric-indent-local-mode -1)))

Thanks for the help!

[purcell]

It's possible that electric-indent-inhibit didn't make it into Emacs in time for the 24.4 freeze: looks like it was added on 7th Oct. I'll see if we can incorporate a more widely effective fix directly into haskell-mode.

[purcell]

I was mistaken: that var is in 24.4. And the MELPA version does correctly inhibit electric-indent-local-mode for me.

[gracjan]

Note that electric-indent-inhibit works only on non-empty lines or when cursor in not in the first column. So electric-indent-inhibit does not really fix the 'newline-and-indent' aggresive behavior of haskell-simple-indent:

 (unless (and electric-indent-inhibit
        (not at-newline)
    (indent-according-to-mode))))))

[gracjan]

@purcell: I still get 'newline-and-indent' despite your changes in 99658ce

[ivan-m]

I think we need to do something similar in haskell-cabal-mode as well, as electric-indent can do weird indentation there as well.

[sirlensalot]

Given the bad support for electric-indent-inhibit noted in #377 (comment) I propose haskell-mode go for a full shutdown of electric indent a la #377 (comment)