Function insertAt

src/cli/components/editor-logic.ts:34–37

(text: string, cursor: number, s: string)

/** Insert `s` at `cursor`. Returns new text and the cursor after the inserted text. */
export function insertAt(text: string, cursor: number, s: string): { text: string; cursor: number } {
  const c = Math.max(0, Math.min(cursor, text.length));
  return { text: text.slice(0, c) + s + text.slice(c), cursor: c + s.length };
}

/** Backspace one char left of cursor. */
export function backspace(text: string, cursor: number): { text: string; cursor: number } {