Type Alias: ResultFor<R, T, E>

ResultFor<R, T, E> = true extends HasPromise<R> ? ResultAsync<T, E> : Result<T, E>

Resolves to the appropriate Result type (sync or async) based on the input type.

Typically used to conditionally infer return types based on whether the original computation was async.

Type Parameters

R

R

The reference type to inspect for a Promise.

T

T

The type of the Success value.

E

E

The type of the Failure value.

Examples

import { import ResultResult } from '@praha/byethrow';

type type R = Promise<Result.Result<number, string>>R = import ResultResult.type ResultAsync<T, E> = Promise<Result.Result<T, E>>An asynchronous variant of
Result
, wrapped in a Promise.
@typeParamT  - The type of the Success value.@typeParamE  - The type of the Failure value.@exampleimport { Result } from '@praha/byethrow';

const fetchData = async (): Result.ResultAsync<string, Error> => {
  try {
    const data = await fetch('...');
    return { type: 'Success', value: await data.text() };
  } catch (err) {
    return { type: 'Failure', error: err as Error };
  }
};
@categoryCore  TypesResultAsync<number, string>;
type type Output = Promise<Result.Result<number, string>>Output = import ResultResult.type ResultFor<R, T, E> = true extends HasPromise<R> ? Result.ResultAsync<T, E> : Result.Result<T, E>Resolves to the appropriate Result type (sync or async) based on the input type.
Typically used to conditionally infer return types based on whether the original computation was async.
@typeParamR  - The reference type to inspect for a Promise.@typeParamT  - The type of the Success value.@typeParamE  - The type of the Failure value.@exampleWith  a Promise-returning function
import { Result } from '@praha/byethrow';

type R = Result.ResultAsync<number, string>;
type Output = Result.ResultFor<R, number, string>; // Result.ResultAsync<number, string>
@exampleWith  a non-Promise-returning function
import { Result } from '@praha/byethrow';

type R = Result.Result<number, string>;
type Output = Result.ResultFor<R, number, string>; // Result.Result<number, string>
@categoryCore  TypesResultFor<type R = Promise<Result.Result<number, string>>R, number, string>; // Result.ResultAsync<number, string>

import { import ResultResult } from '@praha/byethrow';

type type R = Result.Success<number> | Result.Failure<string>R = import ResultResult.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.@exampleimport { Result } from '@praha/byethrow';

const doSomething = (): Result.Result<number, string> => {
  return Math.random() > 0.5
    ? { type: 'Success', value: 10 }
    : { type: 'Failure', error: 'Oops' };
};
@categoryCore  TypesResult<number, string>;
type type Output = Result.Success<number> | Result.Failure<string>Output = import ResultResult.type ResultFor<R, T, E> = true extends HasPromise<R> ? Result.ResultAsync<T, E> : Result.Result<T, E>Resolves to the appropriate Result type (sync or async) based on the input type.
Typically used to conditionally infer return types based on whether the original computation was async.
@typeParamR  - The reference type to inspect for a Promise.@typeParamT  - The type of the Success value.@typeParamE  - The type of the Failure value.@exampleWith  a Promise-returning function
import { Result } from '@praha/byethrow';

type R = Result.ResultAsync<number, string>;
type Output = Result.ResultFor<R, number, string>; // Result.ResultAsync<number, string>
@exampleWith  a non-Promise-returning function
import { Result } from '@praha/byethrow';

type R = Result.Result<number, string>;
type Output = Result.ResultFor<R, number, string>; // Result.Result<number, string>
@categoryCore  TypesResultFor<type R = Result.Success<number> | Result.Failure<string>R, number, string>; // Result.Result<number, string>

#Type Alias: ResultFor<R, T, E>

#Type Parameters

#R

#T

#E

#Examples

Type Alias: ResultFor<R, T, E>

Type Parameters

R

T

E

Examples