Interface: IResult<T, E>

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

Type parameter
`T`
`E`

Methods

`[iterator]`()

[iterator](): Generator<T, any, unknown>

Returns an iterator over the possibly contained value.

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

Returns

Generator<T, any, unknown>

Examples

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

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

See

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:863

and()

and<U>(result: Result<U, E>): Result<U, E>

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

Type parameters

Type parameter
`U`

Parameters

Parameter	Type	Description
`result`	`Result`<`U`, `E`>	The result to check.

Returns

Result<U, E>

Examples

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

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:601

andThen()

andThen<U>(cb: (value: T) => Result<U, E>): Result<U, 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.

Type parameters

Type parameter
`U`

Parameters

Parameter	Type	Description
`cb`	(`value`: `T`) => `Result`<`U`, `E`>	The predicate.

Returns

Result<U, E>

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:622

contains()

contains(value: T): boolean

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

Parameters

Parameter	Type	Description
`value`	`T`	The value to compare.

Returns

boolean

Examples

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

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:703

containsErr()

containsErr(error: E): boolean

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

Parameters

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

Returns

boolean

Examples

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

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:727

eq()

eq(other: Result<T, E>): boolean

Checks whether or not other equals with self.

Parameters

Parameter	Type	Description
`other`	`Result`<`T`, `E`>	The other result to compare.

Returns

boolean

See

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:805

err()

err(): Option<E>

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

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

Returns

Option<E>

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:139

expect()

expect(message: string): T

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.

Parameters

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

Returns

T

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:419

expectErr()

expectErr(message: string): 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.

Parameters

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

Returns

E

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:444

flatten()

flatten<IT>(this: Result <Result<IT, E>, E>): Result<IT, E>

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

Type parameters

Type parameter
`IT`

Parameters

Parameter	Type
`this`	`Result` <`Result`<`IT`, `E`>, `E`>

Returns

Result<IT, E>

Examples

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

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:766

inspect()

inspect(cb: (value: T) => void): this

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

Parameters

Parameter	Type	Description
`cb`	(`value`: `T`) => `void`	The predicate.

Returns

this

Examples

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

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

See

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:308

inspectAsync()

inspectAsync(cb: (value: T) => Awaitable<void>): Promise <IResult<T, E>>

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

Parameters

Parameter	Type	Description
`cb`	(`value`: `T`) => `Awaitable`<`void`>	The predicate.

Returns

Promise <IResult<T, E>>

Examples

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

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

Note

This is an extension not supported in Rust

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:328

inspectErr()

inspectErr(cb: (error: E) => void): this

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

Parameters

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

Returns

this

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:348

inspectErrAsync()

inspectErrAsync(cb: (error: E) => Awaitable<void>): Promise <IResult<T, E>>

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

Parameters

Parameter	Type	Description
`cb`	(`error`: `E`) => `Awaitable`<`void`>	The predicate.

Returns

Promise <IResult<T, E>>

Examples

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

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

Note

This is an extension not supported in Rust

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:368

intoOkOrErr()

intoOkOrErr(): T | E

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

Returns

T | E

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:784

intoPromise()

intoPromise(): Promise <Result <Awaited<T>, Awaited<E>>>

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

Returns

Promise <Result <Awaited<T>, Awaited<E>>>

Example

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

Note

This is an extension not supported in Rust

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:797

isErr()

isErr(): this is Err<E>

Returns true if the result is Err.

Returns

this is Err<E>

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:75

isErrAnd()

isErrAnd<R>(cb: (error: E) => R): this is Err<E> & R

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

Type parameters

Type parameter
`R` extends `boolean`

Parameters

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

Returns

this is Err<E> & R

Examples

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

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:99

isOk()

isOk(): this is Ok<T>

Returns true if the result is Ok.

Returns

this is Ok<T>

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:34

isOkAnd()

isOkAnd<R>(cb: (value: T) => R): this is Ok<T> & R

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

Type parameters

Type parameter
`R` extends `boolean`

Parameters

Parameter	Type
`cb`	(`value`: `T`) => `R`

Returns

this is Ok<T> & R

Examples

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

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:57

iter()

iter(): Generator<T, any, unknown>

Returns an iterator over the possibly contained value.

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

Returns

Generator<T, any, unknown>

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:394

map()

map<U>(cb: (value: T) => U): 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.

Type parameters

Type parameter
`U`

Parameters

Parameter	Type	Description
`cb`	(`value`: `T`) => `U`	The predicate.

Returns

Result<U, E>

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:159

mapErr()

mapErr<F>(cb: (error: E) => F): 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.

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

Type parameters

Type parameter
`F`

Parameters

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

Returns

Result<T, F>

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:258

mapErrInto()

mapErrInto<IT, IE>(cb: (error: E) => Result<IT, IE>): Result<T | IT, IE>

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.

Type parameters

Type parameter
`IT`
`IE`

Parameters

Parameter	Type	Description
`cb`	(`error`: `E`) => `Result`<`IT`, `IE`>	The predicate.

Returns

Result<T | IT, IE>

Examples

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

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:288

mapInto()

mapInto<IT, IE>(cb: (value: T) => Result<IT, IE>): Result<IT, E | IE>

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.

Type parameters

Type parameter
`IT`
`IE`

Parameters

Parameter	Type	Description
`cb`	(`value`: `T`) => `Result`<`IT`, `IE`>	The predicate.

Returns

Result<IT, E | IE>

Examples

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

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')
);

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:190

mapOr()

mapOr<U>(defaultValue: U, cb: (value: T) => U): 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.

Type parameters

Type parameter
`U`

Parameters

Parameter	Type	Description
`defaultValue`	`U`	The default value to use.
`cb`	(`value`: `T`) => `U`	The predicate.

Returns

U

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:213

mapOrElse()

mapOrElse<U>(op: (error: E) => U, cb: (value: T) => U): 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.

Type parameters

Type parameter
`U`

Parameters

Parameter	Type	Description
`op`	(`error`: `E`) => `U`	The predicate that is run on `Err`.
`cb`	(`value`: `T`) => `U`	The predicate that is run on `Ok`.

Returns

U

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:236

match()

match<OkValue, ErrValue>(branches: object): OkValue | ErrValue

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

Type parameters

Type parameter
`OkValue`
`ErrValue`

Parameters

Parameter	Type	Description
`branches`	`object`	The branches to match.
`branches.err`	-
`branches.ok`	-

Returns

OkValue | ErrValue

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:836

ne()

ne(other: Result<T, E>): boolean

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

Parameters

Parameter	Type	Description
`other`	`Result`<`T`, `E`>	The other result to compare.

Returns

boolean

See

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:813

ok()

ok(): Option<T>

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

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

Returns

Option<T>

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:119

or()

or<F>(result: Result<T, F>): Result<T, F>

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.

Type parameters

Type parameter
`F`

Parameters

Parameter	Type	Description
`result`	`Result`<`T`, `F`>	The result to check.

Returns

Result<T, F>

Examples

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

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

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:658

orElse()

orElse<F>(cb: (error: E) => Result<T, F>): Result<T, F>

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.

Type parameters

Type parameter
`F`

Parameters

Parameter	Type	Description
`cb`	(`error`: `E`) => `Result`<`T`, `F`>	The predicate.

Returns

Result<T, F>

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:679

transpose()

transpose<IT>(this: Result <Option<IT>, E>): Option <Result<IT, 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)).

Type parameters

Type parameter
`IT`

Parameters

Parameter	Type
`this`	`Result` <`Option`<`IT`>, `E`>

Returns

Option <Result<IT, 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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:743

unwrap()

unwrap(): T

Returns the contained Ok value.

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

Returns

T

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:472

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.

Returns

E

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:500

unwrapOr()

unwrapOr<V>(defaultValue: V): T | V

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.

Type parameters

Type parameter
`V`

Parameters

Parameter	Type	Description
`defaultValue`	`V`	The default value.

Returns

T | V

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:527

unwrapOrElse()

unwrapOrElse<V>(op: (error: E) => V): T | V

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

Type parameters

Type parameter
`V`

Parameters

Parameter	Type	Description
`op`	(`error`: `E`) => `V`	The predicate.

Returns

T | V

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:548

unwrapRaw()

unwrapRaw(): T

Returns the contained Ok value.

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

Returns

T

Examples

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

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

Source

projects/utilities/packages/result/src/lib/Result/IResult.ts:574

Interface: IResult<T, E>

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contains()

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containsErr()

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eq()

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err()

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expect()

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expectErr()

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flatten()

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inspect()

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inspectAsync()

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inspectErr()