From a3f00c4e629b34d17bb5522a9bb4c093b70f6de6 Mon Sep 17 00:00:00 2001
From: Carlo Hamalainen <carlo@carlo-hamalainen.net>
Date: Mon, 25 Jul 2016 20:53:08 +0800
Subject: [PATCH] Add commands GhcModOpenHaddockVismode and
 GhcModEchoUrlVismode for looking up symbol passed as visual mode selection.

---
 after/ftplugin/haskell/ghcmod.vim | 11 +++++-
 autoload/ghcmod.vim               | 21 ++++++++++
 autoload/ghcmod/command.vim       | 64 +++++++++++++++++++++++++++++++
 3 files changed, 95 insertions(+), 1 deletion(-)

diff --git a/after/ftplugin/haskell/ghcmod.vim b/after/ftplugin/haskell/ghcmod.vim
index 5492baa..113248a 100644
--- a/after/ftplugin/haskell/ghcmod.vim
+++ b/after/ftplugin/haskell/ghcmod.vim
@@ -59,6 +59,11 @@ command! -buffer -nargs=0 -bang GhcModCheckAsync call ghcmod#command#async_make(
 command! -buffer -nargs=0 -bang GhcModLintAsync call ghcmod#command#async_make('lint', <bang>0)
 command! -buffer -nargs=0 -bang GhcModCheckAndLintAsync call ghcmod#command#check_and_lint_async(<bang>0)
 command! -buffer -nargs=0 -bang GhcModExpand call ghcmod#command#expand(<bang>0)
+command! -buffer -nargs=? -bang GhcModOpenDoc call ghcmod#command#opendoc(<q-args>, <bang>0)
+command! -buffer -nargs=? -bang GhcModDocUrl call ghcmod#command#echo_doc_url(<q-args>, <bang>0)
+command! -buffer -nargs=? -bang GhcModOpenHaddockVismode call ghcmod#command#opendoc(<q-args>, <bang>0, 1)
+command! -buffer -nargs=? -bang GhcModEchoUrlVismode     call ghcmod#command#echo_doc_url(<q-args>, <bang>0, 1)
+
 let b:undo_ftplugin .= join(map([
       \ 'GhcModType',
       \ 'GhcModTypeInsert',
@@ -72,7 +77,11 @@ let b:undo_ftplugin .= join(map([
       \ 'GhcModCheckAsync',
       \ 'GhcModLintAsync',
       \ 'GhcModCheckAndLintAsync',
-      \ 'GhcModExpand'
+      \ 'GhcModExpand',
+      \ 'GhcModOpenDoc',
+      \ 'GhcModDocUrl',
+      \ 'GhcModOpenHaddockVismode',
+      \ 'GhcModEchoUrlVismode',
       \ ], '"delcommand " . v:val'), ' | ')
 let b:undo_ftplugin .= ' | unlet b:did_ftplugin_ghcmod'
 
diff --git a/autoload/ghcmod.vim b/autoload/ghcmod.vim
index 145c614..390636e 100644
--- a/autoload/ghcmod.vim
+++ b/autoload/ghcmod.vim
@@ -22,6 +22,27 @@ function! ghcmod#info(fexp, path, ...) "{{{
   return s:remove_dummy_prefix(l:output)
 endfunction "}}}
 
+function! ghcmod#get_visual_selection()
+  " http://stackoverflow.com/a/6271254
+  let [lnum1, col1] = getpos("'<")[1:2]
+  let [lnum2, col2] = getpos("'>")[1:2]
+  let lines = getline(lnum1, lnum2)
+  let lines[-1] = lines[-1][: col2 - (&selection == 'inclusive' ? 1 : 2)]
+  let lines[0] = lines[0][col1 - 1:]
+  return join(lines, "\n")
+endfunction
+
+function! ghcmod#get_doc_url(path, module, fexp, line, col) "{{{
+  let l:cmd = ghcmod#build_command(['imported-from', a:path, a:line, a:col, a:fexp])
+  let l:output = ghcmod#system(l:cmd)
+  let l:lines = split(l:output, '\n')
+  let l:lastline = l:lines[-1]
+
+  if l:lastline =~ "^file.*"
+    return l:lastline
+  endif
+endfunction "}}}
+
 function! ghcmod#split(line, col, path, ...) "{{{
   " `ghc-mod split` is available since v5.0.0.
   let l:cmd = ghcmod#build_command(['split', a:path, a:line, a:col])
diff --git a/autoload/ghcmod/command.vim b/autoload/ghcmod/command.vim
index d8541a7..19bfe7d 100644
--- a/autoload/ghcmod/command.vim
+++ b/autoload/ghcmod/command.vim
@@ -271,4 +271,68 @@ function! s:open_quickfix() "{{{
   endif
 endfunction "}}}
 
+function! ghcmod#command#opendoc(fexp, force, vismode) "{{{
+  let l:path = s:buffer_path(a:force)
+  if empty(l:path)
+    return
+  endif
+  let l:fexp = a:fexp
+  if empty(l:fexp)
+    if a:vismode
+      let l:fexp = ghcmod#get_visual_selection()
+    else
+      let l:fexp = ghcmod#getHaskellIdentifier()
+    endif
+  end
+
+  let l:line = line('.')
+  let l:col = col('.')
+
+  let l:doc_url = ghcmod#get_doc_url(l:path, ghcmod#detect_module(), l:fexp, l:line, l:col)
+
+  if l:doc_url =~ '^file'
+    if exists('g:ghcmod_browser')
+        execute 'silent !' . g:ghcmod_browser . ' ' . l:doc_url . ' >& /dev/null &'
+        execute ':redraw!'
+    else
+      if has("win")
+        echo 'Error, not implemented. Go here: ' . l:doc_url
+      endif
+
+      if has("unix")
+        if system('uname')=~'Darwin'
+          " Redirect output to /dev/null?
+          execute "silent !open " . l:doc_url
+        else
+          execute "silent !xdg-open " . l:doc_url . ' >& /dev/null'
+        endif
+
+        execute ':redraw!'
+      endif
+    endif
+  else
+    echo l:doc_url
+  endif
+endfunction "}}}
+
+function! ghcmod#command#echo_doc_url(fexp, force, vismode) "{{{
+  let l:path = s:buffer_path(a:force)
+  if empty(l:path)
+    return
+  endif
+  let l:fexp = a:fexp
+  if empty(l:fexp)
+    if a:vismode
+      let l:fexp = ghcmod#get_visual_selection()
+    else
+      let l:fexp = ghcmod#getHaskellIdentifier()
+    endif
+  end
+
+  let l:line = line('.')
+  let l:col = col('.')
+
+  echo ghcmod#get_doc_url(l:path, ghcmod#detect_module(), l:fexp, l:line, l:col)
+endfunction "}}}
+
 " vim: set ts=2 sw=2 et fdm=marker: