UListPurpose class

Overview

This is an union object to improve safety and convenience of objects using Enum.

Enum provides a very powerful type for a specific group of data, but at the same time it means a loss of flexibility: values not defined in Enum are either completely ignored or an exception is thrown if parsing fails. This union object exists to solve that problem.

This union object handles the KnownValue, a known enum value defined in Lexicon, and the UnknownValue, an unknown string value not defined in Lexicon. In other words, it can handle unknown values while enjoying the type safety of Enum.

Usage

// use when syntax.
final value = object.when(
  knownValue: (data) => data, // => KnownListPurpose
  unknownValue: (data) => data, // => String
);

// or simpler way.
if (object.isKnownValue) {
  print(object.knownValue); // => KnownListPurpose or null
} else if (object.isUnknownValue) {
  print(object.unknownValue); // => String or null
}
Implementers
Available extensions
Annotations
  • @freezed

Constructors

UListPurpose.knownValue({required KnownListPurpose data})
const
factory
UListPurpose.unknownValue({required String data})
const
factory

Properties

data → Object
no setterinherited
hashCode → int
The hash code for this object.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

map<TResult extends Object?>({required TResult knownValue(UListPurposeKnownValue value), required TResult unknownValue(UListPurposeUnknownValue value)}) → TResult
inherited
mapOrNull<TResult extends Object?>({TResult? knownValue(UListPurposeKnownValue value)?, TResult? unknownValue(UListPurposeUnknownValue value)?}) → TResult?
inherited
maybeMap<TResult extends Object?>({TResult knownValue(UListPurposeKnownValue value)?, TResult unknownValue(UListPurposeUnknownValue value)?, required TResult orElse()}) → TResult
inherited
maybeWhen<TResult extends Object?>({TResult knownValue(KnownListPurpose data)?, TResult unknownValue(String data)?, required TResult orElse()}) → TResult
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited
when<TResult extends Object?>({required TResult knownValue(KnownListPurpose data), required TResult unknownValue(String data)}) → TResult
inherited
whenOrNull<TResult extends Object?>({TResult? knownValue(KnownListPurpose data)?, TResult? unknownValue(String data)?}) → TResult?
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited