Support aliases (strictly).

It's porting of
591cb8fa11 in https://github.com/Shougo/ddc-nvim-lsp/pull/19.

If you alias this source to two or more names, the global environment
variable are conflicted.

Lua evaluation is exclusive, but `async` function in TypeScript may be
interrupted by other operations at right after the `await` statement.

`escapeVimAutoloadName` is for escaping Unicode sequences into vim
variable compatible names. eg:
  - `012abcABC` -> `012abcABC`
    - `lsp/ts` -> `lsp_47_ts`
      - `a-b_c` -> `a_45_b_95_c`

      Converting with escaping `_` to make this injective (=reversible).

And invocations of members of the source (eg: gatherCandidates) may be
shuffled after calling `ddc#refresh_candidates` because ddc.vim uses
`await` before calling them.

autoload/ddc_vim_lsp.vim

@@ -1,4 +1,4 @@
-function! ddc_vim_lsp#_callback(server, position, data) abort
+function! ddc_vim_lsp#_callback(server, position, alias, data) abort
   if lsp#client#is_error(a:data) || !has_key(a:data, 'response') || !has_key(a:data['response'], 'result')
     return
   endif
@@ -9,16 +9,16 @@ function! ddc_vim_lsp#_callback(server, position, data) abort
       \ 'response': a:data['response'],
       \ }
   let lspitems = lsp#omni#get_vim_completion_items(l:options)['items']
- 
+
   if len(lspitems) > 0
-    let g:ddc#source#ddc_vim_lsp#_results = lspitems
-    let g:ddc#source#ddc_vim_lsp#_requested = v:true
+    let g:ddc#source#ddc_vim_lsp#{a:alias}#_results = lspitems
+    let g:ddc#source#ddc_vim_lsp#{a:alias}#_requested = v:true
 
     call ddc#refresh_candidates()
   endif
 endfunction
 
-function! ddc_vim_lsp#request(server_name) abort
+function! ddc_vim_lsp#request(server_name, alias) abort
   let l:server = lsp#get_server_info(a:server_name)
   let l:position = lsp#get_position()
 
@@ -28,6 +28,6 @@ function! ddc_vim_lsp#request(server_name) abort
     \   'textDocument': lsp#get_text_document_identifier(),
     \   'position': l:position,
     \ },
-    \ 'on_notification': function('ddc_vim_lsp#_callback', [l:server, l:position]),
+    \ 'on_notification': function('ddc_vim_lsp#_callback', [l:server, l:position, a:alias]),
     \ })
 endfunction

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

@@ -3,58 +3,103 @@ import {
   Candidate,
 } from "https://deno.land/x/ddc_vim@v0.13.0/types.ts#^";
 
+import { batch, vars } from "https://deno.land/x/ddc_vim@v0.13.0/deps.ts#^";
 import {
-  batch,
-  Denops,
-  vars,
-} from "https://deno.land/x/ddc_vim@v0.13.0/deps.ts#^";
+  GatherCandidatesArguments,
+  OnInitArguments,
+} from "https://deno.land/x/ddc_vim@v0.13.0/base/source.ts#^";
 
+// Vim funcname constraints can be found at :help E124.
+// Leading numbers are allowed in autoload name.
+const escapeVimAutoloadName = (name: string) => {
+  let escaped = "";
+  for (let i = 0; i < name.length; i++) {
+    if (name.charAt(i).match(/[a-zA-Z0-9]/)) escaped += name.charAt(i);
+    else escaped += `_${name.charCodeAt(i)}_`;
+  }
+  return escaped;
+};
+
+const escapeVimAutoloadNameCache = new Map<string, string>();
+const escapeVimAutoloadNameCached = (name: string) => {
+  if (!escapeVimAutoloadNameCache.has(name)) {
+    escapeVimAutoloadNameCache.set(name, escapeVimAutoloadName(name));
+  }
+  return escapeVimAutoloadNameCache.get(name);
+};
+
+// deno-lint-ignore ban-types
 type Params = {};
 
-export class Source extends BaseSource {
-  async onInit(args: {
-    denops: Denops;
-  }): Promise<void> {
+export class Source extends BaseSource<Params> {
+  async onInit(args: OnInitArguments<Params>): Promise<void> {
+    const escaped = escapeVimAutoloadNameCached(this.name);
     await batch(args.denops, async (denops) => {
-      await vars.g.set(denops, "ddc#source#ddc_vim_lsp#_results", []);
-      await vars.g.set(denops, "ddc#source#ddc_vim_lsp#_requested", false);
-      await vars.g.set(denops, "ddc#source#ddc_vim_lsp#_prev_input", "");
+      await vars.g.set(
+        denops,
+        `ddc#source#ddc_vim_lsp#${escaped}#_results`,
+        [],
+      );
+      await vars.g.set(
+        denops,
+        `ddc#source#ddc_vim_lsp#${escaped}#_requested`,
+        false,
+      );
+      await vars.g.set(
+        denops,
+        `ddc#source#ddc_vim_lsp#${escaped}#_prev_input`,
+        "",
+      );
     });
   }
 
-  async gatherCandidates(args: {
-    denops: Denops;
-    context: Context;
-    completeStr: string;
-  }): Promise<Candidate[]> {
+  async gatherCandidates(
+    args: GatherCandidatesArguments<Params>,
+  ): Promise<Candidate[]> {
+    const escaped = escapeVimAutoloadNameCached(this.name);
     const prevInput = await vars.g.get(
       args.denops,
-      "ddc#source#ddc_vim_lsp#_prev_input",
+      `ddc#source#ddc_vim_lsp#${escaped}#_prev_input`,
     );
     const requested = await vars.g.get(
       args.denops,
-      "ddc#source#ddc_vim_lsp#_requested",
+      `ddc#source#ddc_vim_lsp#${escaped}#_requested`,
     );
     if (args.context.input == prevInput && requested) {
-      return await vars.g.get(args.denops, "ddc#source#ddc_vim_lsp#_results");
+      return await vars.g.get(
+        args.denops,
+        `ddc#source#ddc_vim_lsp#${escaped}#_results`,
+        // deno-lint-ignore no-explicit-any
+      ) as any;
     }
 
-    const lspservers = await args.denops.call("lsp#get_allowed_servers");
+    const lspservers: string[] = await args.denops.call(
+      "lsp#get_allowed_servers",
+      // deno-lint-ignore no-explicit-any
+    ) as any;
     if (lspservers.length === 0) {
       return [];
     }
 
     await batch(args.denops, async (denops) => {
-      await vars.g.set(denops, "ddc#source#ddc_vim_lsp#_results", []);
-      await vars.g.set(denops, "ddc#source#ddc_vim_lsp#_requested", false);
       await vars.g.set(
         denops,
-        "ddc#source#ddc_vim_lsp#_prev_input",
+        `ddc#source#ddc_vim_lsp#${escaped}#_results`,
+        [],
+      );
+      await vars.g.set(
+        denops,
+        `ddc#source#ddc_vim_lsp#${escaped}#_requested`,
+        false,
+      );
+      await vars.g.set(
+        denops,
+        `ddc#source#ddc_vim_lsp#${escaped}#_prev_input`,
         args.context.input,
       );
 
       // NOTE: choose first lsp server
-      await denops.call("ddc_vim_lsp#request", lspservers[0]);
+      await denops.call("ddc_vim_lsp#request", lspservers[0], escaped);
     });
 
     return [];