nimma/src/runtime/codegen-functions/in-bounds.mjs

Scalable JSONPath engine.

export default function (sandbox, pos, start, end, step) {
  const value = sandbox.valueAt(-1);
  const actualStart =
    start < 0
      ? Math.max(0, start + value.length)
      : Math.min(value.length, start);
  const actualEnd =
    end < 0 ? Math.max(0, end + value.length) : Math.min(value.length, end);

  return (
    pos >= actualStart &&
    pos < actualEnd &&
    (step === 1 ||
      (actualEnd - Math.abs(step) > 0 && (pos + start) % step === 0))
  );
}