Function indexNodeFinder

src/languages/clojure.ts:48–77

* Creates a node finder which will apply a transformation to the index of a * value node and return the node at the given index of the nodes parent * @param parentFinder A finder which will be applied to the parent to determine * whether it is a match * @param indexTransform A function that will

(
  parentFinder: NodeFinder,
  indexTransform: (index: number) => number
)

 * @returns A node finder based on the given description
 */
function indexNodeFinder(
  parentFinder: NodeFinder,
  indexTransform: (index: number) => number
) {
  return (node: SyntaxNode) => {
    const parent = node.parent;

    if (parent == null || parentFinder(parent) == null) {
      return null;
    }

    const valueNodes = getValueNodes(parent);

    const nodeIndex = valueNodes.findIndex(({ id }) => id === node.id);

    if (nodeIndex === -1) {
      // TODO: In the future we might conceivably try to handle saying "take
      // item" when the selection is inside a comment between the key and value
      return null;
    }

    const desiredIndex = indexTransform(nodeIndex);

    if (desiredIndex === -1) {
      return null;
    }

    return valueNodes[desiredIndex];
  };
}

function itemFinder() {
  return indexNodeFinder(