From 85e9cf90214294102a2459ee013c7c636891e887 Mon Sep 17 00:00:00 2001
From: Raunak Raj <71929976+bajrangCoder@users.noreply.github.com>
Date: Sun, 18 Oct 2026 13:06:57 +0530
Subject: [PATCH] docs(editor-languages): document register options and
 formatAs

---
 docs/utilities/ace-modes.md | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/docs/utilities/ace-modes.md b/docs/utilities/ace-modes.md
index 0718909..a53cf44 100644
--- a/docs/utilities/ace-modes.md
+++ b/docs/utilities/ace-modes.md
@@ -11,7 +11,7 @@ const editorLanguages = acode.require("editorLanguages");
 
 ## Methods
 
-### `register(name, extensions, caption?, loader?)`
+### `register(name, extensions, caption?, loader?, options?)`
 
 Registers a language mode.
 
@@ -19,6 +19,10 @@ Registers a language mode.
 - `extensions`: String or string array (without `.`), for example `"mymode"` or `["mymode", "mym"]`.
 - `caption` (optional): Label shown in UI.
 - `loader` (optional): Function returning a CodeMirror extension (or a Promise resolving to one).
+- `options` (optional):
+  - `aliases`: other names that resolve to this mode.
+  - `filenameMatchers`: `RegExp[]` matched against file names.
+  - `formatAs`: name of a mode whose formatter this mode reuses. See [Formatting](#formatting).
 
 ```javascript
 const editorLanguages = acode.require("editorLanguages");
@@ -43,6 +47,29 @@ const editorLanguages = acode.require("editorLanguages");
 editorLanguages.unregister("myMode");
 ```
 
+## Formatting
+
+A new mode has no formatter, and the built-in Prettier doesn't know its name. If your language is a variant of an existing one, set `formatAs` to reuse that mode's formatter:
+
+```javascript
+editorLanguages.register(
+  "json-bedrock",
+  ["jsonbe"],
+  "JSON (Bedrock)",
+  loadBedrockLanguage,
+  { formatAs: "json" }, // [!code focus]
+);
+```
+
+When the user formats a `json-bedrock` file:
+
+- Acode uses the formatter chosen for `json-bedrock` in **Settings → Formatter**, or the one chosen for `json` if there is none.
+- Prettier formats it with the `json` parser.
+
+In **Settings → Formatter**, the "JSON (Bedrock)" row shows the inherited formatter, for example "Prettier (JSON)", and its picker also lists the formatters available for `json`. Picking one there overrides the inherited choice. This works with any formatter, not only Prettier.
+
+Older Acode versions ignore `formatAs`, so passing it is safe; the mode just has no formatter there.
+
 ## Apply A Mode To Active File
 
 ```javascript