👍 Allow to specify range to undecorate().

Close #162

Author: uga-rosa

denops_std/buffer/README.md

@@ -282,8 +282,8 @@ decorate the buffer.
 
 ### undecorate
 
-Use `undecorate()` to undecorate the `bufnr` buffer decorated with `decorate`
-like:
+Use `undecorate()` to undecorate the `bufnr` buffer from `start` line to `end`
+line decorated with `decorate` like:
 
 ```typescript
 import { Denops } from "../mod.ts";
@@ -311,7 +311,13 @@ export async function main(denops: Denops): Promise<void> {
 
   // Do something
 
-  await undecorate(denops, bufnr);
+  // Ranges are 0-based and exclusive.
+  // Remove only the first highlight.
+  const start = 0;
+  const end = 1;
+  await undecorate(denops, bufnr, start, end);
+  // Start and end are optional. Defaults are 0 and -1 (entire buffer).
+  // await undecorate(denops, bufnr);
 }
 ```
 

denops_std/buffer/decoration.ts

@@ -42,12 +42,14 @@ export function decorate(
 export function undecorate(
   denops: Denops,
   bufnr: number,
+  start = 0,
+  end = -1,
 ): Promise<void> {
   switch (denops.meta.host) {
     case "vim":
-      return vimUndecorate(denops, bufnr);
+      return vimUndecorate(denops, bufnr, start, end);
     case "nvim":
-      return nvimUndecorate(denops, bufnr);
+      return nvimUndecorate(denops, bufnr, start, end);
     default:
       unreachable(denops.meta.host);
   }
@@ -94,10 +96,12 @@ async function vimDecorate(
 async function vimUndecorate(
   denops: Denops,
   bufnr: number,
+  start: number,
+  end: number,
 ): Promise<void> {
-  const propList = await vimFn.prop_list(denops, 1, {
+  const propList = await vimFn.prop_list(denops, start + 1, {
     bufnr,
-    end_lnum: -1,
+    end_lnum: end,
   }) as { id: string; type: string }[];
   const propIds = new Set(
     propList.filter((p) =>
@@ -140,10 +144,12 @@ async function nvimDecorate(
 async function nvimUndecorate(
   denops: Denops,
   bufnr: number,
+  start: number,
+  end: number,
 ): Promise<void> {
   const ns = await nvimFn.nvim_create_namespace(
     denops,
     "denops_std:buffer:decoration:decorate",
   );
-  await nvimFn.nvim_buf_clear_namespace(denops, bufnr, ns, 0, -1);
+  await nvimFn.nvim_buf_clear_namespace(denops, bufnr, ns, start, end);
 }