remote plugins: add support for perl hosts

runtime/autoload/provider/perl.vim

@@ -0,0 +1,73 @@
+if exists('s:loaded_perl_provider')
+  finish
+endif
+
+let s:loaded_perl_provider = 1
+
+function! provider#perl#Detect() abort
+  " use g:perl_host_prof if set or check if perl is on the path
+  let prog = get(g:, 'perl_host_prog', executable('perl') ? 'perl' : '')
+
+  " if perl is available, make sure the required module is available
+  if prog != ''
+    let job_id = jobstart(prog.' -MNeovim::Ext -e "exit 0"', {'stdout_buffered': v:true})
+    let result = jobwait([job_id])
+	if result[0] != 0
+      let prog = ''
+    endif
+  endif
+
+  return prog
+endfunction
+
+function! provider#perl#Prog() abort
+  return s:prog
+endfunction
+
+function! provider#perl#Require(host) abort
+  if s:err != ''
+    echoerr s:err
+    return
+  endif
+
+  let prog = provider#perl#Prog()
+  let args = [s:prog, '-e', 'use Neovim::Ext; start_host();']
+
+  " Collect registered perl plugins into args
+  let perl_plugins = remote#host#PluginsForHost(a:host.name)
+  for plugin in perl_plugins
+    call add(args, plugin.path)
+  endfor
+
+  return provider#Poll(args, a:host.orig_name, '$NVIM_PERL_LOG_FILE')
+endfunction
+
+function! provider#perl#Call(method, args) abort
+  if s:err != ''
+    echoerr s:err
+    return
+  endif
+
+  if !exists('s:host')
+    try
+      let s:host = remote#host#Require('perl')
+    catch
+      let s:err = v:exception
+      echohl WarningMsg
+      echomsg v:exception
+      echohl None
+      return
+    endtry
+  endif
+  return call('rpcrequest', insert(insert(a:args, 'perl_'.a:method), s:host))
+endfunction
+
+let s:err = ''
+let s:prog = provider#perl#Detect()
+let g:loaded_perl_provider = empty(s:prog) ? 1 : 2
+
+if g:loaded_perl_provider != 2
+  let s:err = 'Cannot find perl or the required perl module'
+endif
+
+call remote#host#RegisterPlugin('perl-provider', 'perl', [])

runtime/autoload/remote/host.vim

@@ -203,3 +203,7 @@ call remote#host#Register('ruby', '*.rb',
 " nodejs
 call remote#host#Register('node', '*',
       \ function('provider#node#Require'))
+
+" perl
+call remote#host#Register('perl', '*',
+      \ function('provider#perl#Require'))