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 executedBefore = before.execute(results.toList(), passed);
  final executedAfter = after.execute(results.toList(), passed);
  if (executedBefore.isEmpty) {
    if (executedAfter.isEmpty) {
      return [true];
    } else {
      return [false];
    }
  } else if (executedBefore.length != executedAfter.length) {
    return [false];
  } else {
    executedBefore.removeWhere((lhsElement) =>
        executedAfter.indexWhere((rhsElement) {
          if (lhsElement is FhirDateTime ||
              lhsElement is FhirDate ||
              rhsElement is FhirDateTime ||
              rhsElement is FhirDate) {
            /// As long as one is, we convert them both to strings then back
            /// to DateTimes
            final lhsDateTime = FhirDateTime(lhsElement.toString());
            final rhsDateTime = FhirDateTime(rhsElement.toString());

            final equals = lhsDateTime.isEqual(rhsDateTime);
            if (equals != null) {
              return equals;
            } else {
              return false;
            }
          } else if (lhsElement is ValidatedQuantity) {
            return lhsElement.equivalent(rhsElement);
          } else if (rhsElement is ValidatedQuantity) {
            return rhsElement.equivalent(lhsElement);
          } else if (lhsElement is num || rhsElement is num) {
            final num? lhsNum = num.tryParse(lhsElement.toString());
            final num? rhsNum = num.tryParse(rhsElement.toString());
            final int? sigDigsLhs = lhsNum
                ?.toStringAsExponential()
                .split('e')
                .first
                .replaceAll('.', '')
                .length;
            final int? sigDigsRhs = rhsNum
                ?.toStringAsExponential()
                .split('e')
                .first
                .replaceAll('.', '')
                .length;
            if (sigDigsLhs == null || sigDigsRhs == null) {
              return false;
            } else {
              if (sigDigsLhs < sigDigsRhs) {
                return lhsNum?.toStringAsPrecision(sigDigsLhs) ==
                    rhsNum?.toStringAsPrecision(sigDigsLhs);
              } else {
                return lhsNum?.toStringAsPrecision(sigDigsRhs) ==
                    rhsNum?.toStringAsPrecision(sigDigsRhs);
              }
            }
          } else if (lhsElement is String || rhsElement is String) {
            return lhsElement.toString().toLowerCase() ==
                rhsElement.toString().toLowerCase();
          } else {
            return lhsElement == rhsElement || rhsElement == lhsElement;
          }
        }) !=
        -1);
    return [executedBefore.isEmpty];
  }
}