Class: Err<E>

@sapphire/result.Err

A type used to express computations that can fail, it can be used for returning and propagating errors. This is a type union with the variants Ok(T), representing success and containing a value, and Err(E), representing error and containing an error value.

Typeparam

T The result's type.

Typeparam

E The error's type.

See

https://doc.rust-lang.org/std/result/index.html

Type parameters

Name
`E`

Implements

IResult<any, E>

Constructors

constructor

• new Err<E>(error)

Type parameters

Name
`E`

Parameters

Name	Type
`error`	`E`

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:12

Properties

error

• Private Readonly error: E

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:10

Methods

[iterator]

▸ [iterator](): Generator<never, any, unknown>

Returns an iterator over the possibly contained value.

The iterator yields one value if the result is Ok, otherwise none.

Example

const x = ok(7);
for (const value of x) {
  console.log(value);
}
// Logs 7

Example

const x = err('Nothing!');
for (const value of x) {
  console.log(value);
}
// Doesn't log

See

Returns

Generator<never, any, unknown>

Implementation of

IResult.[iterator]

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:182

and

▸ and(result?): Err<E>

Returns result if the result is Ok, otherwise returns the Err value of itself.

Example

const x: Result<number, string> = ok(2);
const y: Result<string, string> = err('Late error');
assert.equal(x.and(y), err('Late error'));

Example

const x: Result<number, string> = err('Early error');
const y: Result<string, string> = err('Late error');
assert.equal(x.and(y), err('Early error'));

Example

const x: Result<number, string> = ok(2);
const y: Result<string, string> = ok('Hello');
assert.equal(x.and(y), ok('Hello'));

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.and

Parameters

Name	Type	Description
`result?`	`Result`<`any`, `E`>	The result to check.

andThen

▸ andThen(cb?): Err<E>

Calls cb if the result is Ok, otherwise returns the Err value of self.

This function can be used for control flow based on Result values.

Example

function fractionOf4(value: number) {
  return value === 0 ? err('overflowed') : ok(4 / value);
}

assert.equal(ok(2).andThen(fractionOf4), ok(4));
assert.equal(ok(0).andThen(fractionOf4), err('overflowed'));
assert.equal(err('not a number').andThen(fractionOf4), err('not a number'));

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.and_then

Parameters

Name	Type	Description
`cb?`	(`value`: `never`) => `Result`<`any`, `E`>	The predicate.

Returns

Err<E>

Implementation of

IResult.andThen

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:128

contains

▸ contains(value?): false

Returns true if the result is an Ok and the given value strict equals it.

Example

const x: Result<number, string> = ok(2);
assert.equal(x.contains(2), true);

Example

const x: Result<number, string> = ok(3);
assert.equal(x.contains(2), false);

Example

const x: Result<number, string> = err('Some error message');
assert.equal(x.contains(2), false);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.contains

Parameters

Name	Type	Description
`value?`	`any`	The value to compare.

Returns

false

Implementation of

IResult.contains

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:141

containsErr

▸ containsErr(error): boolean

Returns true if the result is an Err and the given error strict equals it.

Example

const x: Result<number, string> = ok(2);
assert.equal(x.containsErr('Some error message'), false);

Example

const x: Result<number, string> = err('Some error message');
assert.equal(x.containsErr('Some error message'), true);

Example

const x: Result<number, string> = err('Some other error message');
assert.equal(x.containsErr('Some error message'), false);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.contains_err

Parameters

Name	Type	Description
`error`	`E`	The error to compare.

Returns

boolean

Implementation of

IResult.containsErr

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:146

eq

▸ eq(other): false

Checks whether or not other equals with self.

See

https://doc.rust-lang.org/std/cmp/trait.PartialEq.html#tymethod.eq

Parameters

Name	Type	Description
`other`	`Ok`<`any`>	The other result to compare.

Returns

false

Implementation of

IResult.eq

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:166

▸ eq(other): boolean

Parameters

Name	Type
`other`	`Result`<`any`, `E`>

Returns

boolean

Implementation of

IResult.eq

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:167

err

▸ err(): Some<E>

Converts from Result<T, E> to Option<E>.

Converts itself into an Option<E>, and discarding the successful value, if any.

Example

const x: Result<number, string> = ok(2);
assert.equal(x.err(), none);

Example

const x: Result<number, string> = err('Some error message');
assert.equal(x.err(), 'Some error message');

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.err

Returns

Some<E>

Implementation of

IResult.err

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:37

expect

▸ expect(message): never

Returns the contained Ok value.

If the value is an Err, it throws a ResultError with the given message and the content of the Err.

Example

const x = ok(2);
assert.equal(x.expect('Whoops!'), 2);

Example

const x = err('Emergency failure');
assert.throws(() => x.expect('Whoops!'), {
  name: 'ResultError',
  message: 'Whoops',
  value: 'Emergency failure'
});

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.expect

Parameters

Name	Type	Description
`message`	`string`	The message for the error.

Returns

never

Implementation of

IResult.expect

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:93

expectErr

▸ expectErr(message?): E

Returns the contained Err value.

If the value is an Ok, it throws a ResultError with the given message and the content of the Ok.

Example

const x = ok(2);
assert.throws(() => x.expectErr('Whoops!'), {
  name: 'ResultError',
  message: 'Whoops',
  value: 2
});

Example

const x = err('Emergency failure');
assert.equal(x.expectErr('Whoops!'), 'Emergency failure');

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.expect_err

Parameters

Name	Type	Description
`message?`	`string`	The message for the error.

Returns

E

Implementation of

IResult.expectErr

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:97

flatten

▸ flatten(): Err<E>

Converts from Result<Result<T, E>, E> to Result<T, E>.

Example

const x: Result<Result<string, number>, number> = ok(ok('Hello'));
assert.equal(x.flatten(), ok('Hello'));

Example

const x: Result<Result<string, number>, number> = ok(err(6));
assert.equal(x.flatten(), err(6));

Example

const x: Result<Result<string, number>, number> = err(6);
assert.equal(x.flatten(), err(6));

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.flatten

Returns

Err<E>

Implementation of

IResult.flatten

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:154

inspect

▸ inspect(cb?): Err<E>

Calls the provided closure with a reference to the contained value (if Ok).

Seealso

inspectAsync for the awaitable version.

Example

ok(2).inspect(console.log);
// Logs: 2

Example

err('Some error message').inspect(console.log);
// Doesn't log

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.inspect

Parameters

Name	Type	Description
`cb?`	(`value`: `never`) => `void`	The predicate.

Returns

Err<E>

Implementation of

IResult.inspect

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:69

inspectAsync

▸ inspectAsync(cb?): Promise<Err<E>>

Calls the provided closure with a reference to the contained value (if Ok) and awaits it.

Seealso

inspect for the sync version.

Example

await ok(2).inspectAsync(console.log);
// Logs: 2

Example

await err('Some error message').inspectAsync(console.log);
// Doesn't log

Note

This is an extension not supported in Rust

Parameters

Name	Type	Description
`cb?`	(`value`: `never`) => `unknown`	The predicate.

Returns

Promise<Err<E>>

Implementation of

IResult.inspectAsync

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:74

inspectErr

▸ inspectErr(cb): Err<E>

Calls the provided closure with a reference to the contained error (if Err).

Seealso

inspectErrAsync for the awaitable version.

Example

ok(2).inspectErr(console.log);
// Doesn't log

Example

err('Some error message').inspectErr(console.log);
// Logs: Some error message

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.inspect_err

Parameters

Name	Type	Description
`cb`	(`error`: `E`) => `void`	The predicate.

Returns

Err<E>

Implementation of

IResult.inspectErr

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:79

inspectErrAsync

▸ inspectErrAsync(cb): Promise<Err<E>>

Calls the provided closure with a reference to the contained error (if Err) and awaits it.

Seealso

inspectErr for the sync version.

Example

await ok(2).inspectErrAsync(console.log);
// Doesn't log

Example

await err('Some error message').inspectErrAsync(console.log);
// Logs: Some error message

Note

This is an extension not supported in Rust

Parameters

Name	Type	Description
`cb`	(`error`: `E`) => `unknown`	The predicate.

Returns

Promise<Err<E>>

Implementation of

IResult.inspectErrAsync

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:84

intoOkOrErr

▸ intoOkOrErr(): E

Returns the Ok value if self is Ok, and the Err value if self is Err.

Example

let x: Result<number, number> = ok(3);
assert.equal(x.intoOkOrErr(), 3);

Example

let x: Result<number, number> = err(4);
assert.equal(x.intoOkOrErr(), 4);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.into_ok_or_err

Returns

E

Implementation of

IResult.intoOkOrErr

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:158

intoPromise

▸ intoPromise(): Promise<Err<Awaited<E>>>

Returns a Promise object with the awaited value (if Ok) or the awaited error (if Err).

Example

let x = ok(Promise.resolve(3));
assert.equal(await x.intoPromise(), ok(3));

Note

This is an extension not supported in Rust

Returns

Promise<Err<Awaited<E>>>

Implementation of

IResult.intoPromise

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:162

isErr

▸ isErr(): this is Err<E>

Returns true if the result is Err.

Example

const x = ok(-3);
assert.equal(x.isErr(), false);

Example

const x = err('Some error message');
assert.equal(x.isErr(), true);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.is_err

Returns

this is Err<E>

Implementation of

IResult.isErr

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:25

isErrAnd

▸ isErrAnd(cb): boolean

Returns true if the result is Err and the value inside of it matches a predicate.

Example

const x = ok(2);
assert.equal(x.isErrAnd((error) => error instanceof TypeError), false);

Example

const x = err(new Error('Some error message'));
assert.equal(x.isErrAnd((error) => error instanceof TypeError), false);

Example

const x = err(new TypeError('Some error message'));
assert.equal(x.isErrAnd((error) => error instanceof TypeError), true);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.is_err_and

Parameters

Name	Type	Description
`cb`	(`error`: `E`) => `boolean`	The predicate.

Returns

boolean

Implementation of

IResult.isErrAnd

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:29

isOk

▸ isOk(): false

Returns true if the result is Ok.

Example

const x = ok(-3);
assert.equal(x.isOk(), true);

Example

const x = err('Some error message');
assert.equal(x.isOk(), false);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.is_ok

Returns

false

Implementation of

IResult.isOk

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:16

isOkAnd

▸ isOkAnd(cb?): false

Returns true if the result is Ok and the value inside of it matches a predicate.

Example

const x = ok(2);
assert.equal(x.isOkAnd((value) => value > 1), true);

Example

const x = ok(0);
assert.equal(x.isOkAnd((value) => value > 1), false);

Example

const x = err('Some error message');
assert.equal(x.isOkAnd((value) => value > 1), false);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.is_ok_and

Parameters

Name	Type
`cb?`	(`value`: `never`) => `boolean`

Returns

false

Implementation of

IResult.isOkAnd

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:20

iter

▸ iter(): Generator<never, any, unknown>

Returns an iterator over the possibly contained value.

The iterator yields one value if the result is Ok, otherwise none.

Example

const x = ok(7);
for (const value of x.iter()) {
  console.log(value);
}
// Logs 7

Example

const x = err('Nothing!');
for (const value of x.iter()) {
  console.log(value);
}
// Doesn't log

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.iter

Returns

Generator<never, any, unknown>

Implementation of

IResult.iter

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:89

map

▸ map(cb?): Err<E>

Maps a Result<T, E> to Result<U, E> by applying a function to a contained Ok value, leaving an Err value untouched.

Example

const x: Result<number, string> = ok(2);
assert.equal(x.map((value) => value * 2), ok(4));

Example

const x: Result<number, string> = err('Some error message');
assert.equal(x.map((value) => value * 2), err('Some error message'));

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.map

Parameters

Name	Type	Description
`cb?`	(`value`: `never`) => `unknown`	The predicate.

Returns

Err<E>

Implementation of

IResult.map

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:41

mapErr

▸ mapErr<F>(cb): Err<F>

Maps a Result<T, E> to Result<T, F> by applying a function to a contained Err value, leaving an Ok value untouched.

This function can be used to pass through a successful result while handling an error.

Example

const x: Result<number, Error> = ok(2);
assert.equal(x.mapErr((error) => error.message), ok(2));

Example

const x: Result<number, Error> = err(new Error('Some error message'));
assert.equal(x.mapErr((error) => error.message), err('Some error message'));

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.map_err

Type parameters

Name
`F`

Parameters

Name	Type	Description
`cb`	(`error`: `E`) => `F`	The predicate.

Returns

Err<F>

Implementation of

IResult.mapErr

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:61

mapErrInto

▸ mapErrInto<R>(cb): R

Maps a Result<T, E> to Result<T, F> by applying a function to a contained Err value, leaving an Ok value untouched.

This function can be used to pass through a successful result while handling an error.

Unlike mapErr, this method does not wrap the returned value inside Err, but instead, it returns the returned value.

Example

const x: Result<number, Error> = ok(2);
assert.equal(x.mapErrInto((error) => err(error.message)), ok(2));

Example

const x: Result<number, Error> = err(new Error('Some error message'));
assert.equal(x.mapErrInto((error) => err(error.message)), err('Some error message'));

Example

const x: Result<number, Error> = err(new Error('Some error message'));
assert.equal(x.mapErrInto((error) => ok(4)), ok(4));

Note

This is an extension not supported in Rust

Type parameters

Name	Type
`R`	extends `Result`<`any`, `any`>

Parameters

Name	Type	Description
`cb`	(`error`: `E`) => `R`	The predicate.

Returns

R

Implementation of

IResult.mapErrInto

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:65

mapInto

▸ mapInto(cb): Err<E>

Maps a Result<T, E> to Result<T, F> by applying a function to a contained Ok value, leaving an Err value untouched.

Unlike map, this method does not wrap the returned value inside Ok, but instead, it returns the returned value.

Example

const x: Result<number, string> = ok(2);
assert.equal(x.mapInto((value) => ok(value * value)), ok(4));

Example

const x: Result<number, string> = ok(0);
assert.equal(
  x.mapInto((value) => (value === 0 ? err('zero is not divisible') : ok(1 / value))),
  err('zero is not divisible')
);

Example

const x: Result<number, string> = err('Some error message');
assert.equal(x.mapInto((value) => ok(4)), err('Some error message'));

Note

This is an extension not supported in Rust

Parameters

Name	Type	Description
`cb`	(`value`: `never`) => `Result`<`any`, `any`>	The predicate.

Returns

Err<E>

Implementation of

IResult.mapInto

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:46

mapOr

▸ mapOr<U>(defaultValue, cb?): U

Returns the provided default (if Err), or applies a function to the contained value (if Ok),

Arguments passed to mapOr are eagerly evaluated; if you are passing the result of a function call, it is recommended to use mapOrElse, which is lazily evaluated.

Example

const x = ok('hello');
assert.equal(x.mapOr(42, (value) => value.length), 5);

Example

const x = err('Some error message');
assert.equal(x.mapOr(42, (value) => value.length), 42);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.map_or

Type parameters

Name
`U`

Parameters

Name	Type	Description
`defaultValue`	`U`	The default value to use.
`cb?`	(`value`: `never`) => `U`	The predicate.

Returns

U

Implementation of

IResult.mapOr

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:51

mapOrElse

▸ mapOrElse<U>(op, cb?): U

Maps a Result<T, E> to U by applying fallback function default to a contained Err value, or function cb to a contained Ok value.

This function can be used to unpack a successful result while handling an error.

Example

const x: Result<string, string> = ok('hello');
assert.equal(x.mapOrElse((error) => error.length, (value) => value.length), 5);

Example

const x: Result<string, string> = err('Some error message');
assert.equal(x.mapOrElse((error) => error.length, (value) => value.length), 18);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.map_or_else

Type parameters

Name
`U`

Parameters

Name	Type	Description
`op`	(`error`: `E`) => `U`	The predicate that is run on `Err`.
`cb?`	(`value`: `never`) => `U`	The predicate that is run on `Ok`.

Returns

U

Implementation of

IResult.mapOrElse

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:56

match

▸ match<OkValue, ErrValue>(branches): ErrValue

Runs ok function if self is Ok, otherwise runs err function.

Example

const result = ok(4).match({
  ok: (v) => v,
  err: () => 0
});
assert.equal(result, 4);

Example

const result = err('Hello').match({
  ok: (v) => v,
  err: () => 0
});
assert.equal(result, 0);

Type parameters

Name
`OkValue`
`ErrValue`

Parameters

Name	Type	Description
`branches`	`Object`	The branches to match.
`branches.err`	(`error`: `E`) => `ErrValue`	-
`branches.ok`	(`value`: `never`) => `OkValue`	-

Returns

ErrValue

Implementation of

IResult.match

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:178

ne

▸ ne(other): true

Checks whether or not other doesn't equal with self.

See

https://doc.rust-lang.org/std/cmp/trait.PartialEq.html#method.ne

Parameters

Name	Type	Description
`other`	`Ok`<`any`>	The other result to compare.

Returns

true

Implementation of

IResult.ne

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:172

▸ ne(other): boolean

Parameters

Name	Type
`other`	`Result`<`any`, `E`>

Returns

boolean

Implementation of

IResult.ne

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:173

ok

▸ ok(): None

Converts from Result<T, E> to Option<T>.

Converts itself into an Option<T>, and discarding the error, if any.

Example

const x: Result<number, string> = ok(2);
assert.equal(x.ok(), some(2));

Example

const x: Result<number, string> = err('Some error message');
assert.equal(x.ok(), none);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.ok

Returns

None

Implementation of

IResult.ok

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:33

or

▸ or<R>(result): R

Return result if the result is Err, otherwise returns the Ok value of self.

Arguments passed to or are eagerly evaluated; if you are passing the result of a function call, it is recommended to use orElse, which is lazily evaluated.

Example

const x: Result<number, string> = ok(2);
const y: Result<number, string> = err('Late error');
assert.equal(x.or(y), ok(2));

Example

const x: Result<number, string> = err('Early error');
const y: Result<number, string> = ok(2);
assert.equal(x.or(y), ok(2));

Example

const x: Result<number, string> = err('Early error');
const y: Result<number, string> = err('Late error');
assert.equal(x.or(y), err('Late error'));

Example

const x: Result<number, string> = ok(2);
const y: Result<number, string> = ok(100);
assert.equal(x.or(y), ok(2));

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.or

Type parameters

Name	Type
`R`	extends `Result`<`any`, `any`>

Parameters

Name	Type	Description
`result`	`R`	The result to check.

Returns

R

Implementation of

IResult.or

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:133

orElse

▸ orElse<R>(cb): R

Calls cb if the result is Err, otherwise returns the Ok value of self.

This function can be used for control flow based on result values.

Example

const square = (x: number): Result<number, string> => ok(x * x);
const wrapErr = (x: number): Result<number, string> => err(x);

assert.equal(ok(2).orElse(square).orElse(square), ok(2));
assert.equal(ok(2).orElse(wrapErr).orElse(square), ok(2));
assert.equal(err(3).orElse(square).orElse(wrapErr), ok(9));
assert.equal(err(3).orElse(wrapErr).orElse(wrapErr), err(3));

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.or_else

Type parameters

Name	Type
`R`	extends `Result`<`any`, `any`>

Parameters

Name	Type	Description
`cb`	(`error`: `E`) => `R`	The predicate.

Returns

R

Implementation of

IResult.orElse

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:137

transpose

▸ transpose(): Some<Err<E>>

Transposes a Result of an Option into an Option of a Result.

ok(none) will be mapped to none. ok(some(v)) and err(e) will be mapped to some(ok(v)) and some(err(e)).

Example

const x: Result<Option<number>, Error> = ok(some(5));
const y: Option<Result<number, Error>> = some(ok(5));
assert.equal(x.transpose(), y);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.transpose

Returns

Some<Err<E>>

Implementation of

IResult.transpose

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:150

unwrap

▸ unwrap(): never

Returns the contained Ok value.

If the value is an Err, it throws a ResultError with the message, and the content of the Err.

Seealso

Seealso

Seealso

Seealso

Example

const x = ok(2);
assert.equal(x.unwrap(), 2);

Example

const x = err('Emergency failure');
assert.throws(() => x.unwrap(), {
  name: 'ResultError',
  message: 'Unwrap failed',
  value: 'Emergency failure'
});

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.unwrap

Returns

never

Implementation of

IResult.unwrap

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:102

unwrapErr

▸ unwrapErr(): E

Returns the contained Err value.

If the value is an Ok, it throws a ResultError with the message, and the content of the Ok.

Seealso

Seealso

Seealso

Seealso

Example

const x = ok(2);
assert.throws(() => x.unwrapErr(), {
  name: 'ResultError',
  message: 'Unwrap failed',
  value: 2
});

Example

const x = err('Emergency failure');
assert.equal(x.unwrapErr(), 'Emergency failure');

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.unwrap_err

Returns

E

Implementation of

IResult.unwrapErr

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:106

unwrapOr

▸ unwrapOr<T>(defaultValue): T

Returns the contained Ok value or the provided default.

Arguments passed to unwrapOr are eagerly evaluated; if you are passing the result of a function call, it is recommended to use unwrapOrElse, which is lazily evaluated.

Seealso

Seealso

Seealso

Seealso

Example

const x: Result<number, string> = ok(9);
assert.equal(x.unwrapOr(2), 9);

Example

const x: Result<number, string> = err('Error');
assert.equal(x.unwrapOr(2), 2);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.unwrap_or

Type parameters

Name
`T`

Parameters

Name	Type	Description
`defaultValue`	`T`	The default value.

Returns

T

Implementation of

IResult.unwrapOr

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:110

unwrapOrElse

▸ unwrapOrElse<T>(op): T

Returns the contained Ok value or computes it from a closure.

Seealso

Seealso

Seealso

Seealso

Example

const count = (x: string) => x.length;

assert.equal(ok(2).unwrapOrElse(count), 2);
assert.equal(err('hello').unwrapOrElse(count), 5);

See

https://doc.rust-lang.org/std/result/enum.Result.html#method.unwrap_or_else

Type parameters

Name
`T`

Parameters

Name	Type	Description
`op`	(`error`: `E`) => `T`	The predicate.

Returns

T

Implementation of

IResult.unwrapOrElse

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:114

unwrapRaw

▸ unwrapRaw(): never

Returns the contained Ok value.

If the value is an Err, it throws the contained error.

Seealso

Seealso

Seealso

Seealso

Example

const x = ok(2);
assert.equal(x.unwrapRaw(), 2);

Example

const x = err('Emergency failure');
assert.throws(() => x.unwrapRaw(), {
  name: 'Error',
  message: 'Unwrap failed',
  value: 'Emergency failure'
});

Returns

never

Implementation of

IResult.unwrapRaw

Defined in

projects/utilities/packages/result/src/lib/Result/Err.ts:118

Type parameters​

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