Class: Result<T, E, Success>
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 | Default type |
|---|---|
T | - |
E | - |
Success extends boolean | boolean |
Constructors
new Result()
privatenew Result<T,E,Success>(value:If<Success,T,E>,success:Success):Result<T,E,Success>
Parameters
| Parameter | Type |
|---|---|
value | If<Success, T, E> |
success | Success |
Returns
Result<T, E, Success>
Defined in
projects/utilities/packages/result/src/lib/Result.ts:28
Properties
__STATUS__
protected__STATUS__:Success
Internal
Branded value to ensure Success is typed correctly.
Defined in
projects/utilities/packages/result/src/lib/Result.ts:23
[SuccessProperty]
privatereadonly[SuccessProperty]:Success
Defined in
projects/utilities/packages/result/src/lib/Result.ts:26
[ValueProperty]
privatereadonly[ValueProperty]:If<Success,T,E>
Defined in
projects/utilities/packages/result/src/lib/Result.ts:25
Accessors
[toStringTag]
Get Signature
get [toStringTag]():
If<Success,"Ok","Err">
Returns
If<Success, "Ok", "Err">
Defined in
projects/utilities/packages/result/src/lib/Result.ts:1001
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:997
and()
and<
OutputResult>(result:OutputResult):If<Success,OutputResult,Err<E,any>>
Returns result if the result is Ok, otherwise returns the Err value of itself.
Type Parameters
| Type Parameter |
|---|
OutputResult extends Any |
Parameters
| Parameter | Type | Description |
|---|---|---|
result | OutputResult | The result to check. |
Returns
If<Success, OutputResult, Err<E, any>>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:687
andThen()
andThen<
OutputResult>(cb: (value:T) =>OutputResult):If<Success,OutputResult,Err<E,any>>
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 |
|---|
OutputResult extends Any |
Parameters
| Parameter | Type | Description |
|---|---|---|
cb | (value: T) => OutputResult | The predicate. |
Returns
If<Success, OutputResult, Err<E, any>>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:710
contains()
contains(this, value)
contains<
Value>(this:Ok<T,any>,value:Value):this is Ok<Value, any>
Returns true if the result is an Ok and the given value strict equals it.
Type Parameters
| Type Parameter |
|---|
Value |
Parameters
| Parameter | Type | Description |
|---|---|---|
this | Ok<T, any> | - |
value | Value | The value to compare. |
Returns
this is Ok<Value, any>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:797
contains(this, value)
contains(
this:Err<E,any>,value:T):false
Parameters
| Parameter | Type |
|---|---|
this | Err<E, any> |
value | T |
Returns
false
Defined in
projects/utilities/packages/result/src/lib/Result.ts:798
containsErr()
containsErr(this, error)
containsErr(
this:Ok<T,any>,error:E):false
Returns true if the result is an Err and the given error strict equals it.
Parameters
| Parameter | Type | Description |
|---|---|---|
this | Ok<T, any> | - |
error | E | The error to compare. |
Returns
false
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:825
containsErr(this, error)
containsErr<
Value>(this:Err<E,any>,error:Value):this is Err<Value, any>
Type Parameters
| Type Parameter |
|---|
Value |
Parameters
| Parameter | Type |
|---|---|
this | Err<E, any> |
error | Value |
Returns
this is Err<Value, any>
Defined in
projects/utilities/packages/result/src/lib/Result.ts:826
eq()
eq<
OtherValue,OtherError,OtherSuccess>(other:Result<OtherValue,OtherError,OtherSuccess>):this is Result<OtherValue, OtherError, OtherSuccess>
Checks whether or not other equals with self.
Type Parameters
| Type Parameter |
|---|
OtherValue |
OtherError |
OtherSuccess extends boolean |
Parameters
| Parameter | Type | Description |
|---|---|---|
other | Result<OtherValue, OtherError, OtherSuccess> | The other result to compare. |
Returns
this is Result<OtherValue, OtherError, OtherSuccess>
See
https://doc.rust-lang.org/std/cmp/trait.PartialEq.html#tymethod.eq
Defined in
projects/utilities/packages/result/src/lib/Result.ts:926
err()
Converts from Result<T, E> to Option<E>.
Converts itself into an Option<E>, and discarding the successful value, if any.
Returns
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:168
expect()
expect(
message:string):If<Success,T,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.
Parameters
| Parameter | Type | Description |
|---|---|---|
message | string | The message for the error. |
Returns
If<Success, T, never>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:484
expectErr()
expectErr(
message:string):If<Success,never,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
If<Success, never, 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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:512
flatten()
flatten<
InnerResult>(this:Result<InnerResult,E,Success>):If<Success,InnerResult,Err<E,any>>
Converts from Result<Result<T, E>, E> to Result<T, E>.
Type Parameters
| Type Parameter |
|---|
InnerResult extends Any |
Parameters
| Parameter | Type |
|---|---|
this | Result<InnerResult, E, Success> |
Returns
If<Success, InnerResult, Err<E, any>>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:875
inspect()
inspect(
cb: (value:T) =>unknown):this
Calls the provided closure with a reference to the contained value (if Ok).
Parameters
| Parameter | Type | Description |
|---|---|---|
cb | (value: T) => unknown | The predicate. |
Returns
this
Seealso
inspectAsync for the awaitable version.
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:359
inspectAsync()
inspectAsync(
cb: (value:T) =>unknown):Promise<Result<T,E,Success>>
Calls the provided closure with a reference to the contained value (if Ok) and awaits it.
Parameters
| Parameter | Type | Description |
|---|---|---|
cb | (value: T) => unknown | The predicate. |
Returns
Promise<Result<T, E, Success>>
Seealso
inspect for the sync version.
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:382
inspectErr()
inspectErr(
cb: (error:E) =>unknown):this
Calls the provided closure with a reference to the contained error (if Err).
Parameters
| Parameter | Type | Description |
|---|---|---|
cb | (error: E) => unknown | The predicate. |
Returns
this
Seealso
inspectErrAsync for the awaitable version.
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:405
inspectErrAsync()
inspectErrAsync(
cb: (error:E) =>unknown):Promise<Result<T,E,Success>>
Calls the provided closure with a reference to the contained error (if Err) and awaits it.
Parameters
| Parameter | Type | Description |
|---|---|---|
cb | (error: E) => unknown | The predicate. |
Returns
Promise<Result<T, E, Success>>
Seealso
inspectErr for the sync version.
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:428
intoOkOrErr()
intoOkOrErr():
If<Success,T,E>
Returns the Ok value if self is Ok, and the Err value if self is Err.
Returns
If<Success, 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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:895
intoPromise()
intoPromise():
Promise<If<Success,Ok<Awaited<T>,any>,Err<Awaited<E>,any>>>
Returns a Promise object with the awaited value (if Ok) or the awaited error (if Err).
Returns
Promise<If<Success, Ok<Awaited<T>, any>, Err<Awaited<E>, any>>>
Example
let x = ok(Promise.resolve(3));
assert.equal(await x.intoPromise(), ok(3));
Note
This is an extension not supported in Rust
Defined in
projects/utilities/packages/result/src/lib/Result.ts:910
isErr()
isErr():
this is Err<E, T>
Returns true if the result is Err.
Returns
this is Err<E, T>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:96
isErrAnd()
isErrAnd(cb)
isErrAnd<
R>(cb: (error:E) =>error is R):this is Err<R, T>
Returns true if the result is Err and the value inside of it matches a predicate.
Type Parameters
| Type Parameter |
|---|
R |
Parameters
| Parameter | Type | Description |
|---|---|---|
cb | (error: E) => error is R | The predicate. |
Returns
this is Err<R, T>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:122
isErrAnd(cb)
isErrAnd<
R>(cb: (error:E) =>R):this is Err<E, T> & R
Type Parameters
| Type Parameter |
|---|
R extends boolean |
Parameters
| Parameter | Type |
|---|---|
cb | (error: E) => R |
Returns
this is Err<E, T> & R
Defined in
projects/utilities/packages/result/src/lib/Result.ts:123
isOk()
isOk():
this is Ok<T, E>
Returns true if the result is Ok.
Returns
this is Ok<T, E>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:49
isOkAnd()
isOkAnd(cb)
isOkAnd<
R>(cb: (value:T) =>value is R):this is Ok<R, E>
Returns true if the result is Ok and the value inside of it matches a predicate.
Type Parameters
| Type Parameter |
|---|
R |
Parameters
| Parameter | Type |
|---|---|
cb | (value: T) => value is R |
Returns
this is Ok<R, E>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:74
isOkAnd(cb)
isOkAnd<
R>(cb: (value:T) =>R):this is Ok<T, E> & R
Type Parameters
| Type Parameter |
|---|
R extends boolean |
Parameters
| Parameter | Type |
|---|---|
cb | (value: T) => R |
Returns
this is Ok<T, E> & R
Defined in
projects/utilities/packages/result/src/lib/Result.ts:75
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:457
map()
map<
OutputValue>(cb: (value:If<Success,T,never>) =>OutputValue):Result<OutputValue,E,Success>
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 |
|---|
OutputValue |
Parameters
| Parameter | Type | Description |
|---|---|---|
cb | (value: If<Success, T, never>) => OutputValue | The predicate. |
Returns
Result<OutputValue, E, Success>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:190
mapErr()
mapErr<
OutputError>(cb: (error:If<Success,never,E>) =>OutputError):Result<T,OutputError,Success>
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 |
|---|
OutputError |
Parameters
| Parameter | Type | Description |
|---|---|---|
cb | (error: If<Success, never, E>) => OutputError | The predicate. |
Returns
Result<T, OutputError, Success>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:304
mapErrInto()
mapErrInto<
OutputResult>(cb: (error:If<Success,never,E>) =>OutputResult):If<Success,Ok<T,any>,OutputResult>
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 |
|---|
OutputResult extends Any |
Parameters
| Parameter | Type | Description |
|---|---|---|
cb | (error: If<Success, never, E>) => OutputResult | The predicate. |
Returns
If<Success, Ok<T, any>, OutputResult>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:337
mapInto()
mapInto<
OutputResult>(cb: (value:If<Success,T,never>) =>OutputResult):If<Success,OutputResult,Err<E,any>>
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 |
|---|
OutputResult extends Any |
Parameters
| Parameter | Type | Description |
|---|---|---|
cb | (value: If<Success, T, never>) => OutputResult | The predicate. |
Returns
If<Success, OutputResult, Err<E, any>>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:224
mapOr()
mapOr<
MappedOutputValue,DefaultOutputValue>(defaultValue:DefaultOutputValue,cb: (value:If<Success,T,never>) =>MappedOutputValue):If<Success,MappedOutputValue,DefaultOutputValue>
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 |
|---|
MappedOutputValue |
DefaultOutputValue |
Parameters
| Parameter | Type | Description |
|---|---|---|
defaultValue | DefaultOutputValue | The default value to use. |
cb | (value: If<Success, T, never>) => MappedOutputValue | The predicate. |
Returns
If<Success, MappedOutputValue, DefaultOutputValue>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:249
mapOrElse()
mapOrElse<
OutputValue,OutputError>(op: (error:If<Success,never,E>) =>OutputError,cb: (value:If<Success,T,never>) =>OutputValue):If<Success,OutputValue,OutputError>
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 |
|---|
OutputValue |
OutputError |
Parameters
| Parameter | Type | Description |
|---|---|---|
op | (error: If<Success, never, E>) => OutputError | The predicate that is run on Err. |
cb | (value: If<Success, T, never>) => OutputValue | The predicate that is run on Ok. |
Returns
If<Success, OutputValue, OutputError>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:277
match()
match<
OkValue,ErrValue>(branches:object):If<Success,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
If<Success, 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);
Defined in
projects/utilities/packages/result/src/lib/Result.ts:964
ne()
ne(
other:Result<T,E,boolean>):boolean
Checks whether or not other doesn't equal with self.
Parameters
| Parameter | Type | Description |
|---|---|---|
other | Result<T, E, boolean> | The other result to compare. |
Returns
boolean
See
https://doc.rust-lang.org/std/cmp/trait.PartialEq.html#method.ne
Defined in
projects/utilities/packages/result/src/lib/Result.ts:939
ok()
Converts from Result<T, E> to Option<T>.
Converts itself into an Option<T>, and discarding the error, if any.
Returns
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:146
or()
or<
OutputResult>(result:OutputResult):If<Success,Ok<T,any>,OutputResult>
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 |
|---|
OutputResult extends Any |
Parameters
| Parameter | Type | Description |
|---|---|---|
result | OutputResult | The result to check. |
Returns
If<Success, Ok<T, any>, OutputResult>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:748
orElse()
orElse<
OutputResult>(cb: (error:E) =>OutputResult):If<Success,Ok<T,any>,OutputResult>
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 |
|---|
OutputResult extends Any |
Parameters
| Parameter | Type | Description |
|---|---|---|
cb | (error: E) => OutputResult | The predicate. |
Returns
If<Success, Ok<T, any>, OutputResult>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:771
transpose()
transpose<
InnerValue>(this:Result<Option<InnerValue,boolean>,E,Success>):If<Success,Option<Ok<InnerValue,any>,boolean>,Some<Err<E,any>>>
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 |
|---|
InnerValue |
Parameters
| Parameter | Type |
|---|---|
this | Result<Option<InnerValue, boolean>, E, Success> |
Returns
If<Success, Option<Ok<InnerValue, any>, boolean>, Some<Err<E, any>>>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:845
unwrap()
unwrap():
If<Success,T,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.
Returns
If<Success, T, never>
Seealso
Seealso
Seealso
Seealso
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:543
unwrapErr()
unwrapErr():
If<Success,never,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
If<Success, never, E>
Seealso
Seealso
Seealso
Seealso
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:574
unwrapOr()
unwrapOr<
OutputValue>(defaultValue:OutputValue):If<Success,T,OutputValue>
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 |
|---|
OutputValue |
Parameters
| Parameter | Type | Description |
|---|---|---|
defaultValue | OutputValue | The default value. |
Returns
If<Success, T, OutputValue>
Seealso
Seealso
Seealso
Seealso
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:604
unwrapOrElse()
unwrapOrElse<
OutputValue>(op: (error:E) =>OutputValue):If<Success,T,OutputValue>
Returns the contained Ok value or computes it from a closure.
Type Parameters
| Type Parameter |
|---|
OutputValue |
Parameters
| Parameter | Type | Description |
|---|---|---|
op | (error: E) => OutputValue | The predicate. |
Returns
If<Success, T, OutputValue>
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
Defined in
projects/utilities/packages/result/src/lib/Result.ts:627
unwrapRaw()
unwrapRaw():
If<Success,T,never>
Returns the contained Ok value.
If the value is an Err, it throws the contained error.
Returns
If<Success, T, never>
Seealso
Seealso
Seealso
Seealso
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'
});
Defined in
projects/utilities/packages/result/src/lib/Result.ts:655
[hasInstance]()
static[hasInstance](instance:unknown):boolean
Checks if the instance object is an instance of Result, or if it is a Result-like object. This override
exists to interoperate with other versions of this class, such as the one coming from another version of this
library or from a different build.
Parameters
| Parameter | Type | Description |
|---|---|---|
instance | unknown | The instance to check. |
Returns
boolean
Whether or not the instance is a Result.
Example
import { Result } from '@sapphire/result';
const { ok } = require('@sapphire/result');
ok(2) instanceof Result; // true
Defined in
projects/utilities/packages/result/src/lib/Result.ts:1035
all()
staticall<Entries>(this:void,results:Entries):Result<UnwrapOkArray<Entries>,UnwrapErrArray<Entries>[number],boolean>
Creates an Ok that is the combination of all collected Ok values as an array, or the first Err encountered.
Type Parameters
| Type Parameter |
|---|
Entries extends readonly Any[] |
Parameters
| Parameter | Type | Description |
|---|---|---|
this | void | - |
results | Entries | An array of Results. |
Returns
Result<UnwrapOkArray<Entries>, UnwrapErrArray<Entries>[number], boolean>
A new Result.
Defined in
projects/utilities/packages/result/src/lib/Result.ts:1117
any()
staticany<Entries>(this:void,results:Entries):Result<UnwrapOk<Entries[number]>,UnwrapErrArray<Entries>,boolean>
Returns the first encountered Ok, or an Err that is the combination of all collected error values.
Type Parameters
| Type Parameter |
|---|
Entries extends readonly Any[] |
Parameters
| Parameter | Type | Description |
|---|---|---|
this | void | - |
results | Entries | An array of Results. |
Returns
Result<UnwrapOk<Entries[number]>, UnwrapErrArray<Entries>, boolean>
A new Result.
Defined in
projects/utilities/packages/result/src/lib/Result.ts:1138
err()
staticerr<E,T>(this:void,value?:E):Err<E,T>
Type Parameters
| Type Parameter | Default type |
|---|---|
E | undefined |
T | any |
Parameters
| Parameter | Type |
|---|---|
this | void |
value? | E |
Returns
Err<E, T>
Defined in
projects/utilities/packages/result/src/lib/Result.ts:1013
from()
staticfrom<T,E>(this:void,op:ResultResolvable<T,E,boolean> | () =>ResultResolvable<T,E,boolean>):Result<T,E,boolean>
Creates a Result out of a callback.
Type Parameters
| Type Parameter | Default type |
|---|---|
T | - |
E | unknown |
Parameters
| Parameter | Type |
|---|---|
this | void |
op | ResultResolvable<T, E, boolean> | () => ResultResolvable<T, E, boolean> |
Returns
Result<T, E, boolean>
Typeparam
T The result's type.
Typeparam
E The error's type.
Defined in
projects/utilities/packages/result/src/lib/Result.ts:1084
fromAsync()
staticfromAsync<T,E>(this:void,op:Awaitable<ResultResolvable<T,E,boolean>> | () =>Awaitable<ResultResolvable<T,E,boolean>>):Promise<Result<T,E,boolean>>
Creates a Result out of a promise or async callback.
Type Parameters
| Type Parameter | Default type |
|---|---|
T | - |
E | unknown |
Parameters
| Parameter | Type |
|---|---|
this | void |
op | Awaitable<ResultResolvable<T, E, boolean>> | () => Awaitable<ResultResolvable<T, E, boolean>> |
Returns
Promise<Result<T, E, boolean>>
Typeparam
T The result's type.
Typeparam
E The error's type.
Defined in
projects/utilities/packages/result/src/lib/Result.ts:1098
is()
staticis(instance:unknown):instance is Any
Parameters
| Parameter | Type | Description |
|---|---|---|
instance | unknown | The instance to check. |
Returns
instance is Any
true if the instance is a Result or a Result-like object, false otherwise.
Deprecated
Use Result.isResult instead.
Checks if the instance object is an instance of Result, or if it is a Result-like object.
Example
import { Result } from '@sapphire/result';
const { ok } = require('@sapphire/result');
Result.isResult(ok(2)); // true
Defined in
projects/utilities/packages/result/src/lib/Result.ts:1055
isResult()
staticisResult(instance:unknown):instance is Any
Checks if the instance object is an instance of Result, or if it is a Result-like object.
Parameters
| Parameter | Type | Description |
|---|---|---|
instance | unknown | The instance to check. |
Returns
instance is Any
true if the instance is a Result or a Result-like object, false otherwise.
Example
import { Result } from '@sapphire/result';
const { ok } = require('@sapphire/result');
Result.isResult(ok(2)); // true
Defined in
projects/utilities/packages/result/src/lib/Result.ts:1073
ok()
staticok<T,E>(this:void,value?:T):Ok<T,E>
Type Parameters
| Type Parameter | Default type |
|---|---|
T | undefined |
E | any |
Parameters
| Parameter | Type |
|---|---|
this | void |
value? | T |
Returns
Ok<T, E>