haskell-mode includes space before newlines

[bremner]

in http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=570243

Marco Túlio Gontijo e Silva writes

If I have a line like:

Data D = A | B$

With a cursor right after A, and I press , I get:

Data D = A $
  | B$

When I expected to get:

Data D = A$
    | B$

(I included a $ in the end of the line.)

[edit by bremner; fix markup to more clearly show expected results]

[chrisdone]

Which indentation mode?

[bremner]

turn-on-haskell-indentation

[hvr]

I just tried with the latest version, and it gets indented as

Data D = A $
       | B$

i.e. the | is aligned with = as I'd expect... the only thing that's annoying IMHO is that left-over trailing space on the first line which I always need to remove manually (as trailing spaces are often frowned upon and rejected by commit validation scripts, e.g. git diff-index --check ...) .

However, I'm not sure if it's a defect in the first place, that <return> is bound to perform indenting (it's bound to haskell-newline-and-indent in that indentation mode) as I'm actually expecting the indentation mode to do something like that when I press <return>...

PS: on a second thought, maybe <return> should be bound to newline by default and C-j to newline-and-indent to follow common Emacs conventions (it just happens that I've been mapping newline-and-indent to <return> in my config for ages, that I forgot this isn't the default convention) to leave the user the choice whether to rebind <return> to newline-and-indent...

PS2: I noticed only now the issue-title, which wasn't inferable from the issue description to me, sorry for the noise

[bremner]

It is interesting that the indentation behaviour is different in the latest version; I agree that the position of | is also annoying in 2.8.0, but apparently not to the guy who reported it to Debian originally ;)

[gracjan]

To keep whitespace issues under control use https://github.com/glasserc/ethan-wspace

C-mode uses standard newline-and-indent that removes excess whitespace.

haskell-indent uses standard newline-and-indent that removes excess whitespace.

haskell-indentation uses nonstandard haskell-newline-and-indent that does not remove excess whitespace. Anybody knows why does it have special code? What is the purpose?

Patch to make haskell-indentation remove excess whitespace is in pull request:

#43

Oh, I'm learning github... there are two unrelated patches in a single pull request... how surprizing.