Removed syntastic and replaced it with ale

Read more here:
https://github.com/w0rp/ale

sources_non_forked/ale/ale_linters/haskell/ghc-mod.vim

@@ -0,0 +1,16 @@
+" Author: wizzup <wizzup@gmail.com>
+" Description: ghc-mod for Haskell files
+
+call ale#linter#Define('haskell', {
+\   'name': 'ghc-mod',
+\   'executable': 'ghc-mod',
+\   'command': 'ghc-mod --map-file %s=%t check %s',
+\   'callback': 'ale#handlers#haskell#HandleGHCFormat',
+\})
+
+call ale#linter#Define('haskell', {
+\   'name': 'stack-ghc-mod',
+\   'executable': 'stack',
+\   'command': 'stack exec ghc-mod -- --map-file %s=%t check %s',
+\   'callback': 'ale#handlers#haskell#HandleGHCFormat',
+\})

sources_non_forked/ale/ale_linters/haskell/ghc.vim

@@ -0,0 +1,18 @@
+" Author: w0rp <devw0rp@gmail.com>
+" Description: ghc for Haskell files
+
+call ale#Set('haskell_ghc_options', '-fno-code -v0')
+
+function! ale_linters#haskell#ghc#GetCommand(buffer) abort
+    return 'ghc '
+    \   . ale#Var(a:buffer, 'haskell_ghc_options')
+    \   . ' %t'
+endfunction
+
+call ale#linter#Define('haskell', {
+\   'name': 'ghc',
+\   'output_stream': 'stderr',
+\   'executable': 'ghc',
+\   'command_callback': 'ale_linters#haskell#ghc#GetCommand',
+\   'callback': 'ale#handlers#haskell#HandleGHCFormat',
+\})

sources_non_forked/ale/ale_linters/haskell/hdevtools.vim

@@ -0,0 +1,22 @@
+" Author: rob-b, Takano Akio <tak@anoak.io>
+" Description: hdevtools for Haskell files
+
+call ale#Set('haskell_hdevtools_executable', 'hdevtools')
+call ale#Set('haskell_hdevtools_options', '-g -Wall')
+
+function! ale_linters#haskell#hdevtools#GetExecutable(buffer) abort
+    return ale#Var(a:buffer, 'haskell_hdevtools_executable')
+endfunction
+
+function! ale_linters#haskell#hdevtools#GetCommand(buffer) abort
+    return ale#Escape(ale_linters#haskell#hdevtools#GetExecutable(a:buffer))
+        \ . ' check ' . ale#Var(a:buffer, 'haskell_hdevtools_options')
+        \ . ' -p %s %t'
+endfunction
+
+call ale#linter#Define('haskell', {
+\   'name': 'hdevtools',
+\   'executable_callback': 'ale_linters#haskell#hdevtools#GetExecutable',
+\   'command_callback': 'ale_linters#haskell#hdevtools#GetCommand',
+\   'callback': 'ale#handlers#haskell#HandleGHCFormat',
+\})

sources_non_forked/ale/ale_linters/haskell/hlint.vim

@@ -0,0 +1,34 @@
+" Author: jparoz <jesse.paroz@gmail.com>
+" Description: hlint for Haskell files
+
+function! ale_linters#haskell#hlint#Handle(buffer, lines) abort
+    let l:output = []
+
+    for l:error in ale#util#FuzzyJSONDecode(a:lines, [])
+        if l:error.severity is# 'Error'
+            let l:type = 'E'
+        elseif l:error.severity is# 'Suggestion'
+            let l:type = 'I'
+        else
+            let l:type = 'W'
+        endif
+
+        call add(l:output, {
+        \   'lnum': str2nr(l:error.startLine),
+        \   'col': str2nr(l:error.startColumn),
+        \   'end_lnum': str2nr(l:error.endLine),
+        \   'end_col': str2nr(l:error.endColumn),
+        \   'text': l:error.severity . ': ' . l:error.hint . '. Found: ' . l:error.from . ' Why not: ' . l:error.to,
+        \   'type': l:type,
+        \})
+    endfor
+
+    return l:output
+endfunction
+
+call ale#linter#Define('haskell', {
+\   'name': 'hlint',
+\   'executable': 'hlint',
+\   'command': 'hlint --color=never --json -',
+\   'callback': 'ale_linters#haskell#hlint#Handle',
+\})

sources_non_forked/ale/ale_linters/haskell/stack_build.vim

@@ -0,0 +1,22 @@
+" Author: Jake Zimmerman <jake@zimmerman.io>
+" Description: Like stack-ghc, but for entire projects
+"
+" Note: Ideally, this would *only* typecheck. Right now, it also does codegen.
+" See <https://github.com/commercialhaskell/stack/issues/977>.
+
+call ale#Set('haskell_stack_build_options', '--fast')
+
+function! ale_linters#haskell#stack_build#GetCommand(buffer) abort
+    let l:flags = ale#Var(a:buffer, 'haskell_stack_build_options')
+
+    return 'stack build ' . l:flags
+endfunction
+
+call ale#linter#Define('haskell', {
+\   'name': 'stack-build',
+\   'output_stream': 'stderr',
+\   'executable': 'stack',
+\   'command_callback': 'ale_linters#haskell#stack_build#GetCommand',
+\   'lint_file': 1,
+\   'callback': 'ale#handlers#haskell#HandleGHCFormat',
+\})

sources_non_forked/ale/ale_linters/haskell/stack_ghc.vim

@@ -0,0 +1,10 @@
+" Author: w0rp <devw0rp@gmail.com>
+" Description: ghc for Haskell files, using Stack
+
+call ale#linter#Define('haskell', {
+\   'name': 'stack-ghc',
+\   'output_stream': 'stderr',
+\   'executable': 'stack',
+\   'command': 'stack ghc -- -fno-code -v0 %t',
+\   'callback': 'ale#handlers#haskell#HandleGHCFormat',
+\})