call method

@override XPathSequence call(XPathContext context, List<XPathSequence> arguments)

Invokes the function item with the given arguments.

Implementation

@override
XPathSequence call(XPathContext context, List<XPathSequence> arguments) {
  if (arguments.length != 1) {
    throw XPathEvaluationException(
      XPathErrorCode.FOAP0001,
      'Arrays expect exactly 1 argument, but got ${arguments.length}',
    );
  }
  final arg = arguments.single.atomize().firstOrNull;
  if (arg is! XPathInteger) {
    throw XPathEvaluationException(
      XPathErrorCode.XPTY0004,
      'Array index must be an integer, got ${arg?.type}',
    );
  }
  final idx = arg.value.toInt();
  if (idx < 1 || idx > members.length) {
    throw XPathEvaluationException(
      XPathErrorCode.FOAY0001,
      'Array index out of bounds: $idx (length: ${members.length})',
    );
  }
  return members[idx - 1];
}