Add floskell for Haskell formatting

autoload/ale/fix/registry.vim

@@ -190,6 +190,11 @@ let s:default_registry = {
 \       'suggested_filetypes': ['hack'],
 \       'description': 'Fix Hack files with hackfmt.',
 \   },
+\   'floskell': {
+\       'function': 'ale#fixers#floskell#Fix',
+\       'suggested_filetypes': ['haskell'],
+\       'description': 'Fix Haskell files with floskell.',
+\   },
 \   'hfmt': {
 \       'function': 'ale#fixers#hfmt#Fix',
 \       'suggested_filetypes': ['haskell'],

autoload/ale/fixers/floskell.vim

@@ -0,0 +1,20 @@
+" Author: robertjlooby <robertjlooby@gmail.com>
+" Description: Integration of floskell with ALE.
+
+call ale#Set('haskell_floskell_executable', 'floskell')
+
+function! ale#fixers#floskell#GetExecutable(buffer) abort
+    let l:executable = ale#Var(a:buffer, 'haskell_floskell_executable')
+
+    return ale#handlers#haskell_stack#EscapeExecutable(l:executable, 'floskell')
+endfunction
+
+function! ale#fixers#floskell#Fix(buffer) abort
+    let l:executable = ale#fixers#floskell#GetExecutable(a:buffer)
+
+    return {
+    \   'command': l:executable
+    \       . ' %t',
+    \   'read_temporary_file': 1,
+    \}
+endfunction