• English
  • Function: isResult()

    isResult<T, E>(result): result is Result<T, E>

    Type guard to check if a value is a Result.

    Type Parameters

    T

    T

    The type of the success value.

    E

    E

    The type of the error value.

    Parameters

    result

    unknown

    The value to check.

    Returns

    result is Result<T, E>

    true if the value is a Result, otherwise false.

    Example

    import { 
    import Result
    Result
    } from '@praha/byethrow';
    const
    const value: unknown
    value
    : unknown = {
    type: string
    type
    : 'Success',
    value: number
    value
    : 42 };
    if (
    import Result
    Result
    .
    const isResult: <unknown, unknown>(result: unknown) => result is Result.Result<unknown, unknown>

    Type guard to check if a value is a Result .

    @function@typeParamT - The type of the success value.@typeParamE - The type of the error value.@paramresult - The value to check.@returnstrue if the value is a Result, otherwise false.@example
    import { Result } from '@praha/byethrow';
    
    const value: unknown = { type: 'Success', value: 42 };
    if (Result.isResult(value)) {
      // value is now typed as Result<unknown, unknown>
      console.log(value.type); // 'Success' or 'Failure'
    }
    @categoryType Guards
    isResult
    (
    const value: unknown
    value
    )) {
    // value is now typed as Result<unknown, unknown>
    var console: Console
    console
    .
    Console.log(...data: any[]): void

    The console.log() static method outputs a message to the console.

    MDN Reference

    log
    (
    const value: Result.Result<unknown, unknown>
    value
    .
    type: "Success" | "Failure"
    type
    ); // 'Success' or 'Failure'
    }