Indentation has been spoiled

[mrkkrp]

I haven't experienced it before. Try to copy this sample:

module Main (main) where

Now try to type the word import and press TAB, or press it when you're at the beginning of line -- it goes to 4 column and says "Sole indentation". I remember it behaved differently before -- it would stay at 0 column and say "Sole indentation" -- this behavior is better, I think. Could you please fix that or if it's on purpose please explain me why does it behave this way.

[mrkkrp]

Sometimes it's 2nd column, not 4th.

[gracjan]

It should stay at column zero. This is a bug. Are you able to add a test case in `tests/haskell-indentation-tests.el` so that we make sure this works as expected?

[gracjan]

Do you know which version have you been using before? I tried to revert some recent commits and I see no change in bahvior.

[mrkkrp]

@gracjan, I haven't done Haskell for some time, maybe a couple of months, so I cannot tell you. Also, unfortunately I cannot help you with the tests, at least not right now.

[gracjan]

Thanks for help. We will manage somehow.

[vwyu]

This happens when haskell-indent-mode is enabled.

In contrast, when haskell-indentation-mode is enabled, import stays correctly at column 0.

[mrkkrp]

So which mode should one use haskell-indent-mode or haskell-indentation-mode and what's the difference between the two? Why on the earth do you keep two modes that do the same thing? @vwyu, fyi, I've just tried it with haskell-indentation-mode -- the problem persists.

[mrkkrp]

@gracjan, One more thing: does it make sense to enable indentation machinery automatically, just like all other language-specific modes do?

[gracjan]

That is the goal, to make haskell-indentation-mode the default and the only.

Sadly, none of the indentation modes work as advertised so people learned to live with their limitations. haskell-indentation-mode requires a lot more work to be able to subsume everything else.

[mrkkrp]

@gracjan, I have to admit that I've tried both the modes without success. Now I'm using haskell-indent-mode, but after a recent change it's broken even more. Now I'm literally fighting the indentation... this is unbearable. I think I better turn it off. Could you please test all changes yourself before pushing them into the repository, that applies to pull requests. Currently it feels like some hacking is being done without good testing. I see you have some tests, but certainly they cannot catch this sort of bug.

I'm not trying to say that your work is bad, I would rather thank you for your work on this project, but I'm using almost exclusively open-source/free software at home and work and this package is most unstable thing I've ever seen. You probably need more people, but unfortunately I cannot help you right now, because I'm already busy and my free time is consumed by another open source effort.

[gracjan]

Sad state of indentation is known and it is our top priority. We need help there as you noticed.

Having said that haskell-indent-mode has not been touched for months and all work goes into haskell-indentation-mode.

[mrkkrp]

@gracjan, OK, enough is enough. Describe me briefly what should I tweak/know to fix this haskell-indentation-mode, please.

[gracjan]

@kuribas and @nilcons are authors of this part. Can you guys help?

Usually the best starting point is test cases. There are some but nowhere nearly enough.

[mrkkrp]

OK, I've started reading the code on my own. You have various nasty things there.

1. Haskell should be capitalized everywhere.
2. Don't use Emacs `' quoting for anything expect Emacs Lisp functions. You're using it for quoting Haskell keywords, creating nonsensical links (Haskell keyword is meant, hyperlink to Emacs Lisp function is created). I propose using of simple double-quotes for this: "if".
3. Do you really need to have a lighter for this mode? I cannot imagine that anyone would like to waste his mode line space for this really minor mode.
4. You shouldn't have lines longer than 80 characters. It's simple to adhere to this rule in all cases.
5. You're setting "higher" limit for recursion (max max-lisp-eval-depth 600). If you really need it, I don't yet see why. At any rate this is suspicious. Given that default of value of max-lisp-eval-depth is 800, I don't see any reason for this magic. Removing this.
6. Every top-level form should be separated by at least one empty line from other top-level forms. Otherwise code is hard to read because it's unclear where one form ends and another one begins. You can do without empty lines only if you have many similar forms that are readable without space between them.
7. Some functions could really enjoy some documentation done in accordance to Emacs Lisp conventions.
8. Documentation strings should end with a full stop.
9. Some functions names are not Lispy enough: haskell-indentation-bird-outside-codep should be haskell-indentation-bird-outside-code-p because it's multi-word predicate. See Lisp predicate naming conventions. Note sure if this can be changed at this point.
10. Use imperative style in doc-strings everywhere.
11. Please don't quote lambdas with #'. lambda is a macro that quotes itself and expands exactly to (function (lambda (...) ...)). This style is obsolete and redundant.

I will soon open a pull request with cosmetic corrections. I have not yet analyzed the code and its design because I'm too tired right now.

[gracjan]

Your work is appreciated and needed. Keep the good stuff coming.