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) {
  if (results.isEmpty) {
    return [];
  } else {
    /// if there's more than 1 item in context, throw exception
    if (results.length > 1) {
      throw _conversionException('.convertsToQuantity()', results);
    }

    /// otherwise if the first item is a Quantity already, a num or a
    /// bool, this is considered true
    else if (results.first is FhirPathQuantity ||
        results.first is num ||
        results.first is bool) {
      return [true];
    }

    /// If it's a string & convertible to a Quantity using the Regex
    else if (results.first is String &&
        FhirPathQuantity.fhirPathQuantityRegex
            .hasMatch((results.first as String).replaceAll(r"\'", "'"))) {
      return [true];
    }

    /// Otherwise it's definitely false
    else {
      return [false];
    }
  }
}