haskell-indentation mode can't parse -XDoAndIfThenElse syntax

[kini]

As title. The following code compiles and works fine but produces parse errors after the "else":

{-# LANGUAGE DoAndIfThenElse #-}
main :: IO ()
main = do
  if True then
    return ()
  else
    return ()

[gracjan]

Thanks for the report, this is really annoying me too.
Duplicate of #269.

[kini]

Is it a duplicate of #269? #269 doesn't seem to mention DoAndIfThenElse.

[gracjan]

Hmm, I'm not sure anymore. Anyway example in #269 has if..then..else in a do context.

[gracjan]

haskell-indentation after hi2 merge still exhibits this problem.

[gracjan]

@kini: Can you add a test case for this in 'tests/haskell-indenttion-tests.el'?

[ntc2]

@gracjan, this is not a duplicate of #269 and should be reopened: Issue #269 is about indenting code in the then and else blocks of an if-then-else (or perhaps indenting do blocks more generally), whereas this current issue is about indenting the then and else keywords themselves.

[ntc2]

Here is a related issue I reported on intero-mode, that I guess must actually be due to this current issue in haskell-mode: https://github.com/commercialhaskell/intero/issues/327. I'm going to close that issue since it's not actually Intero's fault.

[gracjan]

Okay, I'll reopen to keep confusion at bay. Since I know the elisp code I also know that handling of if-then-else is broken and both issues are about manifestation of brokeness.

[ntc2]

@gracjan, ah, I see. So I guess it could make sense to create a general "if-then-else indentation" is broken issue and close both this and #269, and move all the examples there. I guess an easy way to do this would be to edit one of the issue descriptions and make it more general, instead of actually creating a new issue.