implement feature

autoload/ddc_vim_lsp.vim

@@ -0,0 +1,28 @@
+function! ddc_vim_lsp#_callback(server, position, plugin_name, method_name, data) abort
+  if lsp#client#is_error(a:data) || !has_key(a:data, 'response') || !has_key(a:data['response'], 'result') || !has_key(a:data['response']['result'], 'items')
+    return
+  endif
+
+  call denops#request(a:plugin_name, a:method_name, [a:data['response']['result']['items']])
+endfunction
+
+function! ddc_vim_lsp#request(plugin_name, method_name) abort
+  let l:servers = lsp#get_allowed_servers()
+  if len(l:servers) == 0
+    return
+  endif
+
+  " NOTE: choose first lsp server
+  let l:server_name = l:servers[0]
+  let l:server = lsp#get_server_info(l:server_name)
+  let l:position = lsp#get_position()
+
+  call lsp#send_request(l:server_name, {
+  	\ 'method': 'textDocument/completion',
+  	\ 'params': {
+	\   'textDocument': lsp#get_text_document_identifier(),
+  	\   'position': l:position,
+  	\ },
+  	\ 'on_notification': function('ddc_vim_lsp#_callback', [l:server, l:position, a:plugin_name, a:method_name]),
+  	\ })
+endfunction

denops/ddc/sources/ddc-vim-lsp.ts

@@ -0,0 +1,42 @@
+import {
+  BaseSource,
+  Candidate,
+  Context,
+  DdcOptions,
+  SourceOptions,
+} from "https://deno.land/x/ddc_vim@v0.0.11/types.ts#^";
+
+import {
+  Denops,
+} from "https://deno.land/x/ddc_vim@v0.0.11/deps.ts#^";
+
+import {
+  once
+} from "https://deno.land/x/denops_std@v1.0.1/anonymous/mod.ts";
+
+export class Source extends BaseSource {
+  async gatherCandidates(
+    denops: Denops,
+    context: Context,
+    _ddcOptions: DdcOptions,
+    _sourceOptions: SourceOptions,
+    _sourceParams: Record<string, unknown>,
+    completeStr: string,
+  ): Promise<Candidate[]> {
+    return new Promise((resolve) => {
+      denops.call("ddc_vim_lsp#request", denops.name, once(denops, (response) => {
+        resolve(this.toCandidates(response));
+      })[0])
+    })
+    .then((cs: Candidate[]) => {
+      return cs;
+    });
+  }
+
+  toCandidates(response: unknown[]): Candidate[] {
+    const cs: Candidate[] = response.map((e) => {
+	    return {word: e.label};
+    });
+    return cs;
+  }
+}

plugin/ddc/ddc-vim-lsp.vim

@@ -0,0 +1,10 @@
+if exists('g:loaded_ddc_vim_lsp')
+  finish
+endif
+
+let g:loaded_ddc_vim_lsp = 1
+
+silent! call ddc#register_source({
+			\ 'name': 'ddc-vim-lsp',
+			\ 'path': printf('%s/denops/ddc/sources/ddc-vim-lsp.ts', fnamemodify(expand('<sfile>'), ':h:h:h')),
+			\ })