logo
byethrow
  • Guide
  • Examples
  • API Reference
    @praha/byethrow
    Modules
    Result
    Types
    Type Alias: Failure<E>
    Type Alias: InferFailure<T>
    Type Alias: InferSuccess<T>
    Type Alias: Result<T, E>
    Type Alias: ResultAsync<T, E>
    Type Alias: ResultFor<R, T, E>
    Type Alias: ResultMaybeAsync<T, E>
    Type Alias: Success<T>
    Functions
    Function: andThen()
    Function: andThrough()
    Function: assertFailure()
    Function: assertSuccess()
    Function: bind()
    Function: collect()
    Function: do()
    Function: fail()
    Function: inspect()
    Function: inspectError()
    Function: isFailure()
    Function: isResult()
    Function: isSuccess()
    Function: map()
    Function: mapError()
    Function: orElse()
    Function: parse()
    Function: pipe()
    Function: sequence()
    Function: succeed()
    Function: try()
    Function: unwrap()
    Function: unwrapError()
    📝 Edit this page

    Last Updated:

    Previous pageType Alias: InferFailure<T>Next pageType Alias: Result<T, E>

    #Type Alias: InferSuccess<T>

    InferSuccess<T> = [T] extends [(...args) => ResultMaybeAsync<infer U, any>] ? U : [T] extends [ResultMaybeAsync<infer U, any>] ? U : never

    Defined in: result.ts:170

    Infers the Success value type T from a Result or a function returning a Result.

    #Type Parameters

    #T

    T

    A ResultMaybeAsync type or a function returning it.

    #Examples

    import { 
    import Result
    Result
    } from '@praha/byethrow';
    type
    type R = Result.Success<number> | Result.Failure<string>
    R
    =
    import Result
    Result
    .
    type Result<T, E> = Result.Success<T> | Result.Failure<E>

    A union type representing either a success or a failure.

    @typeParamT - The type of the Success value.@typeParamE - The type of the Failure value.@example
    import { Result } from '@praha/byethrow';
    
    const doSomething = (): Result.Result<number, string> => {
      return Math.random() > 0.5
        ? { type: 'Success', value: 10 }
        : { type: 'Failure', error: 'Oops' };
    };
    @categoryCore Types
    Result
    <number, string>;
    type
    type SuccessValue = number
    SuccessValue
    =
    import Result
    Result
    .
    type InferSuccess<T> = [T] extends [(...args: any[]) => Result.ResultMaybeAsync<infer U, any>] ? U : [T] extends [Result.ResultMaybeAsync<infer U, any>] ? U : never

    Infers the Success value type T from a Result or a function returning a Result.

    @typeParamT - A ResultMaybeAsync type or a function returning it.@example

    From a result object

    import { Result } from '@praha/byethrow';
    
    type R = Result.Result<number, string>;
    type SuccessValue = Result.InferSuccess<R>; // number
    @example

    From a function

    import { Result } from '@praha/byethrow';
    
    const fn = () => Promise.resolve({ type: 'Success', value: 123 } as const);
    type SuccessValue = Result.InferSuccess<typeof fn>; // number
    @categoryInfer Types
    InferSuccess
    <
    type R = Result.Success<number> | Result.Failure<string>
    R
    >; // number
    import { 
    import Result
    Result
    } from '@praha/byethrow';
    const
    const fn: () => Promise<{
        readonly type: "Success";
        readonly value: 123;
    }>
    fn
    = () =>
    var Promise: PromiseConstructor

    Represents the completion of an asynchronous operation

    Promise
    .
    PromiseConstructor.resolve<{
        readonly type: "Success";
        readonly value: 123;
    }>(value: {
        readonly type: "Success";
        readonly value: 123;
    }): Promise<{
        readonly type: "Success";
        readonly value: 123;
    }> (+2 overloads)

    Creates a new resolved promise for the provided value.

    @paramvalue A promise.@returnsA promise whose internal state matches the provided promise.
    resolve
    ({
    type: "Success"
    type
    : 'Success',
    value: 123
    value
    : 123 } as
    type const = {
        readonly type: "Success";
        readonly value: 123;
    }
    const
    );
    type
    type SuccessValue = 123
    SuccessValue
    =
    import Result
    Result
    .
    type InferSuccess<T> = [T] extends [(...args: any[]) => Result.ResultMaybeAsync<infer U, any>] ? U : [T] extends [Result.ResultMaybeAsync<infer U, any>] ? U : never

    Infers the Success value type T from a Result or a function returning a Result.

    @typeParamT - A ResultMaybeAsync type or a function returning it.@example

    From a result object

    import { Result } from '@praha/byethrow';
    
    type R = Result.Result<number, string>;
    type SuccessValue = Result.InferSuccess<R>; // number
    @example

    From a function

    import { Result } from '@praha/byethrow';
    
    const fn = () => Promise.resolve({ type: 'Success', value: 123 } as const);
    type SuccessValue = Result.InferSuccess<typeof fn>; // number
    @categoryInfer Types
    InferSuccess
    <typeof
    const fn: () => Promise<{
        readonly type: "Success";
        readonly value: 123;
    }>
    fn
    >; // number