Add support for .nix files

plugin/syntastic/registry.vim

@@ -55,6 +55,7 @@ let s:_DEFAULT_CHECKERS = {
         \ 'matlab':        ['mlint'],
         \ 'mercury':       ['mmc'],
         \ 'nasm':          ['nasm'],
+        \ 'nix':           ['nix'],
         \ 'nroff':         ['mandoc'],
         \ 'objc':          ['gcc'],
         \ 'objcpp':        ['gcc'],

syntax_checkers/nix/nix.vim

@@ -0,0 +1,43 @@
+"============================================================================
+"File:        nix.vim
+"Description: Check nix syntax using 'nix-instantiate --eval-only'
+"Maintainer:  Tim Cuthbertson <tim@gfxmonk.net>
+"License:     This program is free software. It comes without any warranty,
+"             to the extent permitted by applicable law. You can redistribute
+"             it and/or modify it under the terms of the Do What The Fuck You
+"             Want To Public License, Version 2, as published by Sam Hocevar.
+"             See http://sam.zoy.org/wtfpl/COPYING for more details.
+"
+"============================================================================
+"
+"
+if exists('g:loaded_syntastic_nix_nix_checker')
+    finish
+endif
+let g:loaded_syntastic_nix_nix_checker = 1
+
+let s:save_cpo = &cpo
+set cpo&vim
+
+function! SyntaxCheckers_nix_nix_GetLocList() dict
+    let makeprg = self.makeprgBuild({ 'args': '--parse-only' })
+
+    let errorformat = "%m\\, at %f:%l:%c,"
+        \ ."%m at %f\\, line %l:,"
+        \ ."error: %m\\, in %f"
+
+    return SyntasticMake({
+        \ 'makeprg': makeprg,
+        \ 'errorformat': errorformat,
+        \ 'defaults': {'type': 'e'} })
+endfunction
+
+call g:SyntasticRegistry.CreateAndRegisterChecker({
+    \ 'filetype': 'nix',
+    \ 'name': 'nix',
+    \ 'exec': 'nix-instantiate' })
+
+let &cpo = s:save_cpo
+unlet s:save_cpo
+
+" vim: set sw=4 sts=4 et fdm=marker: