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API Reference
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byethrow
@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: combine()
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: succeed()
Function: try()
Function: unwrap()
Function: unwrapError()

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#Function: isResult()

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

Defined in: functions/is-result.ts:25

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

The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.

The module exports two specific components:

  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without importing the node:console module.

Warning: The global console object's methods are neither consistently synchronous like the browser APIs they resemble, nor are they consistently asynchronous like all other Node.js streams. See the note on process I/O for more information.

Example using the global console:

console.log('hello world');
// Prints: hello world, to stdout
console.log('hello %s', 'world');
// Prints: hello world, to stdout
console.error(new Error('Whoops, something bad happened'));
// Prints error message and stack trace to stderr:
//   Error: Whoops, something bad happened
//     at [eval]:5:15
//     at Script.runInThisContext (node:vm:132:18)
//     at Object.runInThisContext (node:vm:309:38)
//     at node:internal/process/execution:77:19
//     at [eval]-wrapper:6:22
//     at evalScript (node:internal/process/execution:76:60)
//     at node:internal/main/eval_string:23:3

const name = 'Will Robinson';
console.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to stderr

Example using the Console class:

const out = getStreamSomehow();
const err = getStreamSomehow();
const myConsole = new console.Console(out, err);

myConsole.log('hello world');
// Prints: hello world, to out
myConsole.log('hello %s', 'world');
// Prints: hello world, to out
myConsole.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to err

const name = 'Will Robinson';
myConsole.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to err
@seesource
console
.
Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)

Prints to stdout with newline. Multiple arguments can be passed, with the first used as the primary message and all additional used as substitution values similar to printf(3) (the arguments are all passed to util.format()).

const count = 5;
console.log('count: %d', count);
// Prints: count: 5, to stdout
console.log('count:', count);
// Prints: count: 5, to stdout

See util.format() for more information.

@sincev0 .1.100
log
(
const value: Result.Result<unknown, unknown>
value
.
type: "Success" | "Failure"
type
); // 'Success' or 'Failure'
}