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52 lines
1.3 KiB
Dart
52 lines
1.3 KiB
Dart
/// Utility class that simplifies handling errors.
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///
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/// Return a [Result] from a function to indicate success or failure.
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///
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/// A [Result] is either an [Ok] with a value of type [T]
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/// or an [Error] with an [Exception].
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///
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/// Use [Result.ok] to create a successful result with a value of type [T].
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/// Use [Result.error] to create an error result with an [Exception].
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///
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/// Evaluate the result using a switch statement:
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/// ```dart
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/// switch (result) {
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/// case Ok(): {
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/// print(result.value);
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/// }
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/// case Error(): {
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/// print(result.error);
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/// }
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/// }
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/// ```
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sealed class Result<T> {
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const Result();
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/// Creates a successful [Result], completed with the specified [value].
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const factory Result.ok(T value) = Ok._;
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/// Creates an error [Result], completed with the specified [error].
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const factory Result.error(Exception error) = Error._;
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}
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/// A successful [Result] with a returned [value].
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final class Ok<T> extends Result<T> {
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const Ok._(this.value);
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/// The returned value of this result.
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final T value;
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@override
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String toString() => 'Result<$T>.ok($value)';
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}
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/// An error [Result] with a resulting [error].
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final class Error<T> extends Result<T> {
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const Error._(this.error);
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/// The resulting error of this result.
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final Exception error;
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@override
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String toString() => 'Result<$T>.error($error)';
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}
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