Use job support plus FIFO for completion callback

Author: tpope

autoload/dispatch.vim

@@ -172,17 +172,42 @@ function! dispatch#vim_executable() abort
   return s:vim
 endfunction
 
-function! dispatch#has_callback() abort
-  return has('clientserver') && !empty(v:servername)
+function dispatch#has_callback() abort
+  if has('clientserver') && !empty(v:servername)
+    return 1
+  elseif !exists('*job_start') && !exists('*jobstart')
+    return 0
+  endif
+  if !exists('s:has_temp_fifo')
+    let fifo = tempname()
+    call system('mkfifo ' . dispatch#shellescape(fifo))
+    let s:has_temp_fifo = (getftype(fifo) ==# 'fifo')
+    call delete(fifo)
+  endif
+  return s:has_temp_fifo
 endfunction
 
 function! dispatch#callback(request) abort
-  if has('clientserver') && !empty(v:servername) && has_key(s:request(a:request), 'id')
+  let request = s:request(a:request)
+  if !has_key(request, 'id') || !dispatch#has_callback()
+    return ''
+  endif
+  if has('clientserver') && !empty(v:servername)
     return dispatch#shellescape(dispatch#vim_executable()) .
           \ ' --servername ' . dispatch#shellescape(v:servername) .
-          \ ' --remote-expr "' . 'DispatchComplete(' . s:request(a:request).id . ')' . '"'
+          \ ' --remote-expr "' . 'DispatchComplete(' . request.id . ')' . '"'
   endif
-  return ''
+  call system('mkfifo ' . dispatch#shellescape(request.file . '.callback'))
+  let cmd = ['head', '-1', request.file . '.callback']
+  let Cb = { ... -> dispatch#complete(request.id) }
+  if exists('*job_start')
+    call job_start(cmd, {'exit_cb': Cb})
+  elseif exists('*jobstart')
+    call jobstart(cmd, {'on_exit': Cb})
+  else
+    return ''
+  endif
+  return 'echo > ' . request.file . '.callback'
 endfunction
 
 function! dispatch#autowrite() abort

doc/dispatch.txt

@@ -155,11 +155,15 @@ STRATEGIES                                      *dispatch-strategies*
 Strategies are listed in order of precedence.  The first available one is
 used.  Some strategies only provide for a subset of tasks.
 
+Except for Tmux, which uses |VimResized|, all strategies require either |job|
+support plus a file system with FIFOs (basically everything but Windows) or
+|clientserver| support to do foreground makes.
+
 Tmux ~
 
 Foreground makes open in a small split at the bottom.  The closure of the
 pane triggers a |VimResized| event which loads the results into the quickfix
-list.  (All other strategies use the GUI subsystem to get this to work.)
+list.
 
 The tmux strategy can be used from the GUI as well.  Either start Vim from
 inside of tmux or assign g:tmux_session.  This will use a new window for
@@ -169,7 +173,7 @@ Tmux 1.6 or newer is required.
 
 GNU Screen ~
 
-Not used for foreground |:Make| invocations unless you're in GUI Vim.
+A new window is always used, since splits in GNU Screen are awkward.
 
 Windows ~
 
@@ -180,8 +184,7 @@ stealing.
 iTerm ~
 
 This strategy fires if you're in MacVim with at least one iTerm window open,
-or if Vim is running in iTerm itself.  In the latter case, you can't use it
-for foreground |:Make| invocations.
+or if Vim is running in iTerm itself.
 
 X11 ~