===== ISTEM =====
Solve the following programming task.

TASK: Text Editor with Undo and Redo

Write a class 'Editor' that holds a text document (initially an empty string) and a cursor position (initially 0), with these methods:
- type(text): inserts text at the cursor and moves the cursor to the end of the inserted text.
- moveTo(pos): moves the cursor to pos, clamped to the range 0 to the current text length.
- backspace(n): deletes up to n characters immediately before the cursor (fewer if the cursor is closer than n to the start) and moves the cursor back by the number of characters deleted.
- undo(): reverts the most recent undo step. Does nothing if there is none.
- redo(): re-applies the most recently undone step. Does nothing if there is none.
- getText(): returns the current text.
- getCursor(): returns the current cursor position.

Undo steps:
- Every call to type, and every call to backspace that deletes at least one character, is an edit. An edit normally creates a new undo step.
- Exception: a type call is added to the previous undo step, instead of creating a new one, if the method called immediately before it (not counting getText and getCursor) was also type.
- A backspace that deletes nothing (cursor already at 0) changes nothing and creates no undo step.
- Undoing a step restores the text and the cursor to exactly what they were before the step. Redoing a step restores them to exactly what they were at the end of the step.
- Every edit clears the redo history. moveTo, undo and redo never clear it.

STARTER CODE (javascript):
class Editor {
  // Write your code here
}

module.exports = { Editor };


RULES:
- Keep the function name and signature EXACTLY as given.
- Return working code only. No explanations.
- Put the code in a single ``` block.
- Try to solve it first. If you genuinely cannot, write only this single
  line instead of producing faulty code: CANNOT_SOLVE

===== HAM YANIT =====
```javascript
class Editor {
  constructor() {
    this.text = "";
    this.cursor = 0;
    this.undoStack = [];
    this.redoStack = [];
    this.lastOp = null; // tracks last method (excluding getText/getCursor)
  }

  // Helper to clamp cursor position
  _clamp(pos) {
    if (pos < 0) return 0;
    if (pos > this.text.length) return this.text.length;
    return pos;
  }

  type(insertText) {
    const prevText = this.text;
    const prevCursor = this.cursor;

    const before = this.text.slice(0, this.cursor);
    const after = this.text.slice(this.cursor);
    const newText = before + insertText + after;
    const newCursor = this.cursor + insertText.length;

    // Update state first
    this.text = newText;
    this.cursor = newCursor;

    if (this.lastOp === 'type' && this.undoStack.length > 0) {
      // Merge with previous step
      const lastStep = this.undoStack[this.undoStack.length - 1];
      lastStep.newText = newText;
      lastStep.newCursor = newCursor;
    } else {
      // New undo step
      this.undoStack.push({
        prevText,
        prevCursor,
        newText,
        newCursor,
      });
      // Clear redo history on any new edit
      this.redoStack = [];
    }

    this.lastOp = 'type';
  }

  moveTo(pos) {
    this.cursor = this._clamp(pos);
    this.lastOp = 'move';
  }

  backspace(n) {
    const deleteCount = Math.min(n, this.cursor);
    if (deleteCount === 0) {
      this.lastOp = 'backspace';
      return;
    }

    const prevText = this.text;
    const prevCursor = this.cursor;

    const start = this.cursor - deleteCount;
    const newText = this.text.slice(0, start) + this.text.slice(this.cursor);
    const newCursor = start;

    // Update state
    this.text = newText;
    this.cursor = newCursor;

    // Record undo step
    this.undoStack.push({
      prevText,
      prevCursor,
      newText,
      newCursor,
    });
    // Clear redo history
    this.redoStack = [];

    this.lastOp = 'backspace';
  }

  undo() {
    if (this.undoStack.length === 0) return;
    const step = this.undoStack.pop();

    // Restore previous state
    this.text = step.prevText;
    this.cursor = step.prevCursor;

    // Push onto redo stack
    this.redoStack.push(step);

    this.lastOp = 'undo';
  }

  redo() {
    if (this.redoStack.length === 0) return;
    const step = this.redoStack.pop();

    // Reapply new state
    this.text = step.newText;
    this.cursor = step.newCursor;

    // Push back onto undo stack
    this.undoStack.push(step);

    this.lastOp = 'redo';
  }

  getText() {
    return this.text;
  }

  getCursor() {
    return this.cursor;
  }
}

module.exports = { Editor };
```