Recursively update the position of child elements of a group

ts

// Apply the position change diff to all children
const updatePosition = <T extends StateItem>(item: T, diff: paper.Point): T => {
  const newPosition = item.position.add(diff);
  if (isGroupStateItem(item)) {
    const newChildren = item.items.map((x) => (updatePosition(x, diff)))
    return {
      ...item,
      position: newPosition,
      nameplate: updatePosition(item.nameplate, diff),
      items: newChildren,
    }
  } else {
    return {
      ...item, position: newPosition
    }
  }
}

• Examples of generics needed

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