Show :ALEDetail messages in a window

[pushcx]

I'm editing Haskell and my config has nnoremap <leader>? :ALEDetail<cr> to show me detailed error messages. Sometimes the output is the normal multi-line error message I'd expect, sometimes it's run together onto a single line and hard to read. (I'd like it to always be multi-line.) It seems to depend on whether I'm getting details after exiting insert mode or after saving the file.

After inserting and deleting a non-semantic, non-trailing space, the detail was on a single line. Here's the info immediately after:

 Current Filetype: haskell
Available Linters: ['ghc-mod', 'stack-ghc-mod', 'ghc', 'stack-ghc', 'hdevtools', 'hlint']
  Enabled Linters: ['stack-ghc-mod', 'stack-ghc', 'hdevtools', 'hlint']
 Linter Variables:

 Global Variables:

let g:ale_echo_cursor = 1
let g:ale_echo_msg_error_str = 'Error'
let g:ale_echo_msg_format = '%s'
let g:ale_echo_msg_warning_str = 'Warning'
let g:ale_enabled = 1
let g:ale_keep_list_window_open = 0
let g:ale_lint_delay = 200
let g:ale_lint_on_enter = 1
let g:ale_lint_on_save = 1
let g:ale_lint_on_text_changed = 0
let g:ale_linter_aliases = {}
let g:ale_linters = {'haskell': ['stack-ghc-mod', 'stack-ghc', 'hdevtools', 'hlint']}
let g:ale_open_list = 0
let g:ale_set_highlights = 1
let g:ale_set_loclist = 1
let g:ale_set_quickfix = 1
let g:ale_set_signs = 1
let g:ale_sign_column_always = 0
let g:ale_sign_error = '>>'
let g:ale_sign_offset = 1000000
let g:ale_sign_warning = '--'
let g:ale_statusline_format = ['%d error(s)', '%d warning(s)', 'OK']
let g:ale_warn_about_trailing_whitespace = 1
  Command History:

(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1000/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1001/Main.hs''']
(finished - exit code 0) ['/bin/bash', '-c', 'stack exec ghc-mod check ''/tmp/vdwAUCv/1002/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1003/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1004/Main.hs''']
(finished - exit code 0) ['/bin/bash', '-c', 'stack exec ghc-mod check ''/tmp/vdwAUCv/1005/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1006/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1007/Main.hs''']
(finished - exit code 0) ['/bin/bash', '-c', 'stack exec ghc-mod check ''/tmp/vdwAUCv/1008/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1009/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1010/Main.hs''']
(finished - exit code 0) ['/bin/bash', '-c', 'stack exec ghc-mod check ''/tmp/vdwAUCv/1011/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1012/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1013/Main.hs''']
(finished - exit code 0) ['/bin/bash', '-c', 'stack exec ghc-mod check ''/tmp/vdwAUCv/1014/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1015/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1016/Main.hs''']
(finished - exit code 0) ['/bin/bash', '-c', 'stack exec ghc-mod check ''/tmp/vdwAUCv/1017/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1018/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1019/Main.hs''']

If I don't move the cursor I can repeatedly get the single-line output.

If I move the cursor one character to the right, I get multi-line output. Here's the info after that:

 Current Filetype: haskell
Available Linters: ['ghc-mod', 'stack-ghc-mod', 'ghc', 'stack-ghc', 'hdevtools', 'hlint']
  Enabled Linters: ['stack-ghc-mod', 'stack-ghc', 'hdevtools', 'hlint']
 Linter Variables:

 Global Variables:

let g:ale_echo_cursor = 1
let g:ale_echo_msg_error_str = 'Error'
let g:ale_echo_msg_format = '%s'
let g:ale_echo_msg_warning_str = 'Warning'
let g:ale_enabled = 1
let g:ale_keep_list_window_open = 0
let g:ale_lint_delay = 200
let g:ale_lint_on_enter = 1
let g:ale_lint_on_save = 1
let g:ale_lint_on_text_changed = 0
let g:ale_linter_aliases = {}
let g:ale_linters = {'haskell': ['stack-ghc-mod', 'stack-ghc', 'hdevtools', 'hlint']}
let g:ale_open_list = 0
let g:ale_set_highlights = 1
let g:ale_set_loclist = 1
let g:ale_set_quickfix = 1
let g:ale_set_signs = 1
let g:ale_sign_column_always = 0
let g:ale_sign_error = '>>'
let g:ale_sign_offset = 1000000
let g:ale_sign_warning = '--'
let g:ale_statusline_format = ['%d error(s)', '%d warning(s)', 'OK']
let g:ale_warn_about_trailing_whitespace = 1
  Command History:

(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1000/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1001/Main.hs''']
(finished - exit code 0) ['/bin/bash', '-c', 'stack exec ghc-mod check ''/tmp/vdwAUCv/1002/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1003/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1004/Main.hs''']
(finished - exit code 0) ['/bin/bash', '-c', 'stack exec ghc-mod check ''/tmp/vdwAUCv/1005/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1006/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1007/Main.hs''']
(finished - exit code 0) ['/bin/bash', '-c', 'stack exec ghc-mod check ''/tmp/vdwAUCv/1008/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1009/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1010/Main.hs''']
(finished - exit code 0) ['/bin/bash', '-c', 'stack exec ghc-mod check ''/tmp/vdwAUCv/1011/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1012/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1013/Main.hs''']
(finished - exit code 0) ['/bin/bash', '-c', 'stack exec ghc-mod check ''/tmp/vdwAUCv/1014/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1015/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1016/Main.hs''']
(finished - exit code 0) ['/bin/bash', '-c', 'stack exec ghc-mod check ''/tmp/vdwAUCv/1017/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'stack ghc -- -fno-code -v0 ''/tmp/vdwAUCv/1018/Main.hs''']
(finished - exit code 1) ['/bin/bash', '-c', 'hlint --color=never --json - < ''/tmp/vdwAUCv/1019/Main.hs''']

[w0rp]

I reckon showing a window with the message is the way to go. It might be possible to show a custom message in the special "preview" window.

[w0rp]

The messages now appear in a preview window.

[pushcx]

Unfortunately, this persists. I do get a preview window, but sometimes I get a nicely formatted message (yay!) and sometimes I get it smashed to one line:

  filterF :: (Applicative f, Foldable t, Monoid (f a)) => (a -> Bool) -> t a -> f a                 
>>filterF p = foldMap (\x -> if p x then (:x) else (:[])) []                                        
  ~                                                                                                 
  ~                                                                                                 
  ~                                                                                                 
  ~                                                                                                 
exercises.hs [haskell]                                                                     58, 47/47
• Couldn't match type ‘f’ with ‘[]’ ‘f’ is a rigid type variable bound by the type signature for:   filterF :: forall (f :: * -> *) (t :: * -> *) a. (Applicative f, Foldable t, Monoid (f a)) => (a -> Bool) -> t a -> f a at exercises.hs:46:12 Expected type: t a -> f a Actual type: a -> [a] • In the  expression: foldMap (\ x -> if p x then (: x) else (: [])) [] In an equation for ‘filterF’: filterF p = foldMap (\ x -> if p x then (: x) else (: [])) [] • Relevant bindings include filterF :: (a ->  Bool) -> t a -> f a (bound at exercises.hs:47:1)                                                    
~                                                                                                   
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~                                                                                                   
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~      

(If that's not super clear, I copied off my terminal - the top is the window of the code I was editing; the bottom is the preview window with the linter error on one line instead of with newlines and indentation.)

[w0rp]

The Haskell issue is being tracked here: #918

I don't use Haskell myself. I'll leave that to anyone who knows how to fix that issue without breaking something.

[pushcx]

Ah, thanks!

[bitterjug]

@w0rp Thanks for this fix, just what I was looking for today.
:PlugUpdate ale and I have it! 😀