execute method

@override List execute(List results, Map<String, dynamic> passed)

The iterable, nested function that evaluates the entire FHIRPath expression one object at a time

Implementation

@override
List execute(List results, Map<String, dynamic> passed) {
  final leftOperand = before.execute(results.toList(), passed);
  final rightOperand = after.execute(results.toList(), passed);

  if (leftOperand.isEmpty) {
    return [false];
  }

  if (rightOperand.isEmpty) {
    return [];
  }

  if (rightOperand.length > 1) {
    throw FhirPathEvaluationException(
        "The 'contains' operator is expecting a single item on its right side. Found $rightOperand",
        operation: 'contains',
        collection: results);
  }

  final rightItem = rightOperand.first.toString();

  return [
    leftOperand.firstWhere((leftItem) => leftItem.toString() == rightItem,
            orElse: () => null) !=
        null
  ];
}