Err<T, E> class

An Err<T, E> is a Result that represents a failure.

You can create an Err using either the Err(E) constructor or the Result.err(E) factory constructor.

Inheritance

Constructors

Err(E err)
Create an Err result with the given error.

Properties

hashCode → int
The hash code for this object.
no setterinherited
props → List<Object?>
The list of properties that will be used to determine whether two instances are equal.
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
stringify → bool
If set to true, the toString method will be overridden to output this instance's props.
no setter

Methods

and(Result<T, E> res) → Result<T, E>
Returns res if the result is Ok, otherwise returns this.
override
andThen(Result<T, E> op(T)) → Result<T, E>
Calls op with the Ok value if the result is Ok, otherwise returns this.
override
err() → Option<E>
Converts the Result into an Option containing the error, if any. Otherwise returns None if the result is a value.
override
expect(String msg) → T
Unwraps a result, yielding the content of an Ok.
override
expectErr(String msg) → E
Unwraps a result, yielding the content of an Err.
override
fold<U, F>(U ok(T), F err(E)) → Result<U, F>
Invoke either the ok or the err function based on the result.
override
isErr() → bool
Returns true if the option is a Err value.
override
isOk() → bool
Returns true if the option is a Ok value.
override
map<U>(U op(T)) → Result<U, E>
Maps a Result<T, E> to Result<U, E> by applying a function to a contained Ok value, leaving an Err value untouched.
override
mapErr<F>(F op(E)) → Result<T, F>
Maps a Result<T, E> to Result<T, F> by applying a function to a contained Err value, leaving an Ok value untouched.
override
mapOr<U>(U op(T), U opt) → U
Applies a function to the contained value (if any), or returns the provided default (if not).
override
mapOrElse<U>(U op(T), U errOp(E)) → U
Maps a Result<T, E> to U by applying a function to a contained Ok value, or a fallback function to a contained Err value.
override
match<R>(R okop(T), R errop(E)) → R
Invokes either the okop or the errop depending on the result.
override
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
ok() → Option<T>
Converts the Result into an Option containing the value, if any. Otherwise returns None if the result is an error.
override
or(Result<T, E> res) → Result<T, E>
Returns res if the result is an Err, otherwise returns this.
override
orElse(Result<T, E> op(E)) → Result<T, E>
Calls op with the Err value if the result is Err, otherwise returns this.
override
toString() → String
A string representation of this object.
inherited
unwrap() → T
Unwraps a result, yielding the content of an Ok.
override
unwrapErr() → E
Unwraps a result, yielding the content of an Err.
override
unwrapOr(T opt) → T
Unwraps a result, yielding the content of an Ok. Else, it returns opt.
override
unwrapOrElse(T op(E)) → T
Unwraps a result, yielding the content of an Ok. If the value is an Err then it calls op with its value.
override
when<R>({required R ok(T), required R err(E)}) → R
Invokes either ok or err depending on the result.
override

Operators

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