👍 Sharing same helper functions between different versions

Closes #191

Author: Milly

denops_std/buffer/buffer.ts

@@ -15,14 +15,14 @@ import {
 import { tryDecode } from "./fileencoding.ts";
 import { generateUniqueString } from "../util.ts";
 
-const cacheKey = Symbol("denops_std/buffer/buffer.ts");
-const suffix = generateUniqueString();
+const cacheKey = "denops_std/buffer/buffer.ts@1";
 
 async function ensurePrerequisites(denops: Denops): Promise<string> {
-  if (cacheKey in denops.context) {
-    return suffix;
+  if (typeof denops.context[cacheKey] === "string") {
+    return denops.context[cacheKey];
   }
-  denops.context[cacheKey] = true;
+  const suffix = generateUniqueString();
+  denops.context[cacheKey] = suffix;
   const script = `
   function! DenopsStdBufferOpen_${suffix}(bang, mods, opener, cmdarg, bufname) abort
     execute printf('%s %s%s %s \`=a:bufname\`', a:mods, a:opener, a:bang ? '!' : '', a:cmdarg)

denops_std/function/getreginfo.ts

@@ -3,14 +3,14 @@ import { lt } from "https://deno.land/std@0.171.0/semver/mod.ts";
 import { execute } from "../helper/mod.ts";
 import { generateUniqueString } from "../util.ts";
 
-const cacheKey = Symbol("denops_std/function/getreginfo.ts");
-const suffix = generateUniqueString();
+const cacheKey = "denops_std/function/getreginfo.ts@1";
 
 async function ensurePrerequisites(denops: Denops): Promise<string> {
-  if (cacheKey in denops.context) {
-    return suffix;
+  if (typeof denops.context[cacheKey] === "string") {
+    return denops.context[cacheKey];
   }
-  denops.context[cacheKey] = true;
+  const suffix = generateUniqueString();
+  denops.context[cacheKey] = suffix;
   const script = `
   function! DenopsStdFunctionGetreginfo_${suffix}(...) abort
     let l:result = call('getreginfo', a:000)

denops_std/helper/echo.ts

@@ -2,15 +2,15 @@ import type { Denops } from "https://deno.land/x/denops_core@v4.0.0/mod.ts";
 import { execute } from "./execute.ts";
 import { generateUniqueString } from "../util.ts";
 
-const cacheKey = Symbol("denops_std/helper/echo");
+const cacheKey = "denops_std/helper/echo@1";
 const cacheKeySilent = "denops_std/helper/echo/silent@1";
-const suffix = generateUniqueString();
 
 async function ensurePrerequisites(denops: Denops): Promise<string> {
-  if (cacheKey in denops.context) {
-    return suffix;
+  if (typeof denops.context[cacheKey] === "string") {
+    return denops.context[cacheKey];
   }
-  denops.context[cacheKey] = true;
+  const suffix = generateUniqueString();
+  denops.context[cacheKey] = suffix;
   const script = `
   let g:loaded_denops_std_helper_echo_${suffix} = 1
   let s:denops_std_helper_echo_timer = 0

denops_std/helper/input.ts

@@ -8,14 +8,14 @@ import * as anonymous from "../anonymous/mod.ts";
 import { execute } from "./execute.ts";
 import { generateUniqueString } from "../util.ts";
 
-const cacheKey = Symbol("denops_std/helper/input");
-const suffix = generateUniqueString();
+const cacheKey = "denops_std/helper/input@1";
 
 async function ensurePrerequisites(denops: Denops): Promise<string> {
-  if (cacheKey in denops.context) {
-    return suffix;
+  if (typeof denops.context[cacheKey] === "string") {
+    return denops.context[cacheKey];
   }
-  denops.context[cacheKey] = true;
+  const suffix = generateUniqueString();
+  denops.context[cacheKey] = suffix;
   const script = `
   let s:loaded_denops_std_helper_input_${suffix} = 1