pkg/edit: Press Ctrl-Alt-V to insert the name of the next key.

Implemented with an unstable builtin without an accompanying test for now, due
to the ongoing off-branch TUI rewrite.

This fixes #1180.

0.22.0-release-notes.md

@@ -1,5 +1,8 @@
 # Notable new features
 
+-   Pressing `Ctrl-Alt-V` in the REPL now enters a mode where the name of the
+    next key pressed will be inserted into the buffer.
+
 # Notable bugfixes
 
 -   The `lower` glob modifier (as in `echo *[lower]`) now correctly matches

pkg/edit/builtins.go

@@ -66,6 +66,29 @@ func insertRaw(app cli.App, tty cli.TTY) {
 	app.PushAddon(w)
 }
 
+func insertKeyName(app cli.App) {
+	codeArea, ok := focusedCodeArea(app)
+	if !ok {
+		return
+	}
+	w := modes.NewStub(modes.StubSpec{
+		Bindings: tk.FuncBindings(func(w tk.Widget, event term.Event) bool {
+			switch event := event.(type) {
+			case term.KeyEvent:
+				codeArea.MutateState(func(s *tk.CodeAreaState) {
+					s.Buffer.InsertAtDot(ui.Key(event).String())
+				})
+				app.PopAddon()
+				return true
+			default:
+				return false
+			}
+		}),
+		Name: " KEY NAME ",
+	})
+	app.PushAddon(w)
+}
+
 var errMustBeKeyOrString = errors.New("must be key or string")
 
 func toKey(v any) (ui.Key, error) {
@@ -143,8 +166,9 @@ func wordify(fm *eval.Frame, code string) error {
 
 func initTTYBuiltins(app cli.App, tty cli.TTY, nb eval.NsBuilder) {
 	nb.AddGoFns(map[string]any{
-		"insert-raw": func() { insertRaw(app, tty) },
-		"clear":      func() { clear(app, tty) },
+		"insert-raw":       func() { insertRaw(app, tty) },
+		"-insert-key-name": func() { insertKeyName(app) },
+		"clear":            func() { clear(app, tty) },
 	})
 }
 

pkg/edit/init.elv

@@ -42,6 +42,7 @@ set insert:binding = (binding-table [
   &Ctrl-K=    $kill-line-right~
 
   &Ctrl-V= $insert-raw~
+  &Ctrl-Alt-V= $-insert-key-name~
 
   &Alt-,=  $lastcmd:start~
   &Alt-.=  $insert-last-word~