Turn-on-haskell-indentation hook won't enable haskell-indentation

[dredozubov]

After recent updates(at least i think it's related to them) i experience following error when emacs tries to indent a haskell source:

You tried to do an indentation command, but an indentation mode has not been enabled yet.

Run M-x describe-variable haskell-mode-hook for a list of such modes.

Inspecting haskell-mode-hook shows:

haskell-mode-hook is a variable defined in `haskell-mode.el'.
Its value is
(company-mode haskell-auto-insert-module-template flymake-hlint-load
              (lambda nil
                (ghc-init))
              interactive-haskell-mode turn-on-haskell-indentation)


  This variable may be risky if used as a file-local variable.

Documentation:
Hook run after entering Haskell mode.
No problems result if this variable is not bound.
`add-hook' automatically binds it.  (This is true for all hook variables.)

I have a (add-hook 'haskell-mode-hook 'turn-on-haskell-indentation) line in my ~/.emacs and it worked until recently. Running M-x haskell-indentation-mode manually helps with this issue(and then it repeats with other buffers).

[geraldus]

I've faced same issue, but I thought it was my fault.

[geraldus]

I'm not sure is this related to issue subject, but in past interactive-mode always asked me to start a new session or select existing one when I open haskell source file from new location (i.e. project). And now if I open .hs file interactive-mode will be activated silently, and will ask nothing.

[dredozubov]

@gracjan thanks for clarification on the matter.

It should be enabled as (add-hook 'haskell-mode-hook 'haskell-indentation-mode), not (add-hook 'haskell-mode-hook 'turn-on-haskell-indentation).

Docs are not up to date with this and i was thinking of fixing it and opening a PR quickly, but it seems that it is a bigger issue. Isn't turn-on- counterparts supposed to go if they're not working anymore? It seems unintentional that these functions do not work automatically as hooks, maybe it should be fixed w/o updating docs?

[gracjan]

You are right on both points:

1. Documentation should be updated.
2. Old functions should still work (marked as deprecated).

I'm not sure why they stopped working.

[geraldus]

In my case M-x turn-on-haskell-indentation works, but does it silently.

[geraldus]

@dredozubov is it still relevant (sorry I've missid Gitter notifications)?

[biboudis]

Just a small remark because I struggled with this for a couple of minutes. Order matters.

(add-hook 'haskell-mode-hook 'haskell-indentation-mode)
(add-hook 'haskell-mode-hook 'interactive-haskell-mode)

Not the other way around.

[gracjan]

Nice catch. Minor modes should not interfere. Can you debug this so that we know why does it need the order as you described?

[biboudis]

Thx. I will investigate this with my colleague who is a more advanced emacs user than me. I will post findings here /cc @gbalats.