Some work for preconfigured servers

autoload/langserver/client.vim

@@ -144,6 +144,7 @@ endfunction
 function! s:lsp_send_request(id, opts) abort " opts = { method, params?, on_notification }
     if has_key(s:lsp_clients, a:id)
         let l:client = s:lsp_clients[a:id]
+        let l:type_of_msg = 'Request'
 
         if has_key(a:opts, 'req_id')
             let l:req_seq = a:opts.req_id
@@ -157,10 +158,18 @@ function! s:lsp_send_request(id, opts) abort " opts = { method, params?, on_noti
             let l:msg.params = a:opts.params
         endif
 
+        " I don't think you should be able to do these at the same time...
+        " Not going to do anything about that yet though
         if has_key(a:opts, 'result')
+            let l:type_of_msg = 'Response (result)'
             let l:msg.result = a:opts.result
         endif
 
+        if has_key (a:opts, 'response')
+            let l:type_of_msg = 'Reponse (response)'
+            let l:msg.response = a:opts.response
+        endif
+
         let l:json = json_encode(l:msg)
         let l:req_data = 'Content-Length: ' . len(l:json) . "\r\n\r\n" . l:json
 
@@ -173,7 +182,8 @@ function! s:lsp_send_request(id, opts) abort " opts = { method, params?, on_noti
             let l:client.opts.on_stderr = a:opts.on_stderr
         endif
 
-        call langserver#log#log('debug', printf('Sending request: %s, %s',
+        call langserver#log#log('debug', printf('Sending %s: %s, %s',
+                    \ l:type_of_msg,
                     \ a:id,
                     \ string(l:msg)
                     \ ))

preconfigured/freebroccolo/ocaml-language-server/callbacks.vim

@@ -1,20 +1,34 @@
-function! s:give_word_at_position(context) abort
+function! s:give_word_at_position(id, data, event) abort
+  call langserver#log#server_request(a:id, a:data, a:event)
   "  'params': 
   "      {'uri': 'file:///home/tj/Downloads/example-ocaml-merlin/src/main.ml',
   "      'position': {'character': 9, 'line': 6}
   "      }
-  if !has_key(a:context, 'uri') || !has_key(a:context, 'position')
-    " TODO: Log an error?
+  if !has_key(a:data.request.params, 'uri') || !has_key(a:data.request.params, 'position')
+    call langserver#log#log('error', 'Unable to handle callback for: ' . string(a:data), v:true)
     return
   endif
 
-  let l:loc_bufnr = bufnr(langserver#util#get_filename(langserver#util#get_lsp_id(), a:context.uri))
-  let l:loc_line = langserver#util#get_line(l:loc_bufnr, a:context.uri, a.position.line - 1)
+  if v:false
+    let l:loc_bufnr = bufnr(langserver#util#get_filename(langserver#util#get_lsp_id(), a:data.request.params.uri))
+    let l:loc_line = langserver#util#get_line(l:loc_bufnr, a:data.request.params.uri, a:data.request.params.position.line - 1)
+  endif
 
-  call langserver#log#log('error', 'LOC LINE: ' . l:loc_line, v:true)
+  call langserver#client#send(a:id, {
+        \ 'req_id': a:data.request.id,
+        \ 'method': a:data.request.method,
+        \ 'request': a:data.request,
+        \ 'result': expand('<cword>'),
+        \ 'response': {
+          \ 'result': expand('<cword>'),
+        \ },
+        \ })
+  return v:true
 endfunction
 
 
-let s:register_callbacks = {
+function! Preconfigured_freebroccolo_ocaml_language_server() abort
+  return {
       \ 'reason.client.giveWordAtPosition': function('s:give_word_at_position'),
       \ }
+endfunction