From d14c0973f1e6967e67ca74f37a16263000d98604 Mon Sep 17 00:00:00 2001
From: Dag Odenhall <dag.odenhall@gmail.com>
Date: Mon, 2 Apr 2012 18:09:59 +0200
Subject: [PATCH] autotags

---
 autoload/vim2hs/haskell/tags.vim |  8 ++++++++
 doc/vim2hs.txt                   | 14 ++++++++++++++
 plugin/haskell_tags.vim          | 20 ++++++++++++++++++++
 3 files changed, 42 insertions(+)
 create mode 100644 autoload/vim2hs/haskell/tags.vim
 create mode 100644 plugin/haskell_tags.vim

diff --git a/autoload/vim2hs/haskell/tags.vim b/autoload/vim2hs/haskell/tags.vim
new file mode 100644
index 0000000..04f1bbe
--- /dev/null
+++ b/autoload/vim2hs/haskell/tags.vim
@@ -0,0 +1,8 @@
+function! vim2hs#haskell#tags#fasttags() " {{{
+  silent !find -iname '*.hs' | xargs fast-tags
+endfunction " }}}
+
+
+function! vim2hs#haskell#tags#hasktags() " {{{
+  silent !hasktags -c --ignore-close-implementation .
+endfunction " }}}
diff --git a/doc/vim2hs.txt b/doc/vim2hs.txt
index e69aa7e..b148ef9 100644
--- a/doc/vim2hs.txt
+++ b/doc/vim2hs.txt
@@ -116,5 +116,19 @@ Whether to add named patterns to Tabular useful for Haskell development.  This
 is enabled by default if Tabular is installed: >
   let g:haskell_tabular = 1
 <
+                                                         *g:haskell_autotags*
+Generate a tags file when Vim is started in a directory containing a "*.cabal"
+file, and update it when saving "*.hs" files.
+
+See also |g:haskell_tags_generator|.
+
+Disabled by default: >
+  let g:haskell_autotags = 0
+<
+                                                   *g:haskell_tags_generator*
+The program to use for |g:haskell_autotags|.  Valid values are "fast-tags" and
+"hasktags" and requires the respective packages from Hackage.  Default: >
+  let g:haskell_tags_generator = 'fast-tags'
+<
 
  vim:tw=78:et:ft=help:norl:
diff --git a/plugin/haskell_tags.vim b/plugin/haskell_tags.vim
new file mode 100644
index 0000000..64d7e3e
--- /dev/null
+++ b/plugin/haskell_tags.vim
@@ -0,0 +1,20 @@
+if glob('*.cabal') ==# ''
+  finish
+endif
+
+call vim2hs#letdefault('g:haskell_autotags'       , 0)
+call vim2hs#letdefault('g:haskell_tags_generator' , 'fast-tags')
+
+if !g:haskell_autotags
+  finish
+endif
+
+if g:haskell_tags_generator ==# 'fast-tags'
+  if !executable('fast-tags') | finish | endif
+  autocmd BufWritePost *.hs call vim2hs#haskell#tags#fasttags()
+  call vim2hs#haskell#tags#fasttags()
+elseif g:haskell_tags_generator == 'hasktags'
+  if !executable('hasktags') | finish | endif
+  autocmd BufWritePost *.hs call vim2hs#haskell#tags#hasktags()
+  call vim2hs#haskell#tags#hasktags()
+endif