simplify some things

src/App.tsx

@@ -2,6 +2,7 @@ import { useEffect, useRef, useState } from 'react';
 import './App.css'
 import { Editor, type EditorState } from './Editor'
 import { initialEditorState, nonEmptyEditorState, tripleFunctionCallEditorState } from "./configurations";
+import { CommandContext } from './CommandContext';
 
 export function App() {
   const [history, setHistory] = useState([initialEditorState]);
@@ -48,22 +49,48 @@ export function App() {
     window.onkeydown = onKeyDown;
   }, []);
 
+  const commands = [
+    ["call"     , "[c] call"              ],
+    ["eval"     , "[u] [Tab] [Enter] eval"],
+    ["transform", "[t] transform"         ],
+    ["let"      , "[=] let ... in ..."    ],
+  ];
+
+  const [highlighted, setHighlighted] = useState(
+    commands.map(() => false));
+
+  const doHighlight = Object.fromEntries(commands.map(([id], i) => {
+    return [id, () => {
+      setHighlighted(h => h.with(i, true));
+      setTimeout(() => setHighlighted(h => h.with(i, false)), 100);
+    }];
+  }));
+
   return (
     <>
       <header>
         <button disabled={history.length===1} onClick={onUndo}>Undo ({history.length-1}) [Ctrl+Z]</button>
         <button disabled={future.length===0} onClick={onRedo}>Redo ({future.length})  [Ctrl+Shift+Z]</button>
+        Commands:
+        {
+          commands.map(([_, descr], i) =>
+            <span key={i} className={'command' + (highlighted[i] ? (' highlighted') : '')}>
+              {descr}
+            </span>)
+        }
       </header>
 
       <main>
-        <Editor
-          state={history.at(-1)!}
-          setState={pushHistory}
-          onResolve={() => {}}
-          onCancel={() => {}}
-          filter={() => true}
-          focus={true}
-        />
+        <CommandContext value={doHighlight}>
+          <Editor
+            state={history.at(-1)!}
+            setState={pushHistory}
+            onResolve={() => {}}
+            onCancel={() => {}}
+            filter={() => true}
+            focus={true}
+          />
+        </CommandContext>
       </main>
 
       <footer>