Autoindent sometimes indents too much

[mcandre]

I sometimes have to comment out (turn-on-haskell-indentation) in my .emacs, as the current implementation sometimes indents too far deeply. This occurs at the first character of function signatures, for example, if the cursor is on the f in fibber :: Int -> Int:

#!/usr/bin/env runhaskell

fibber :: Int -> Int
fibber 0 = 0
fibber 1 = 1
fibber n = fibber (n - 1) + fibber (n - 2)

main :: IO ()
main = print $ fibber 20

Then pressing Tab there results in:

#!/usr/bin/env runhaskell

  fibber :: Int -> Int
fibber 0 = 0
fibber 1 = 1
fibber n = fibber (n - 1) + fibber (n - 2)

main :: IO ()
main = print $ fibber 20

A similar error happens with the cursor beginning on the empty line between the shebang and the signature; pressing Tab results in improper indentation being inserted.

[ivan-m]

What would you expect hitting Tab to do there?

[mcandre]

At the top level, I expect pressing Tab to do nothing, because indentation doesn't make sense there.

If I wrote a module declaration between the shebang and fibber signature, then indentation would make sense.

[ivan-m]

Except you can indent top-level declarations... you just have to ensure that all top-level declarations are indented by the same amount.

[mcandre]

Fair enough.

However, when I press tab in a case expression, haskell-mode often indents several widths deeper than the last line.

[gracjan]

We have just merged new version of haskell-indentation that should solve a lot of problems. I'm closing this particular issue, but do not hessitate to open new issue with specific report about new haskell-indentation.