#Function: inspect()
Executes a side effect function on the success value of a Result or ResultAsync, without modifying the original result. This is useful for debugging, logging, or performing other side effects while maintaining the original value and error state.
#Type Param
The input Result or ResultAsync.
#Type Param
The return type of the inspection function.
#Examples
import { import Result Result } from '@praha/byethrow';
const const result: Result.Result<42, never> result = import Result Result .const pipe: <Result.Result<42, never>, Result.Result<42, never>>(a: Result.Result<42, never>, ab: (a: Result.Result<42, never>) => Result.Result<42, never>) => Result.Result<42, never> (+25 overloads) pipe (
import Result Result .const succeed: <42>(value: 42) => Result.Result<42, never> (+1 overload) succeed (42),
import Result Result .const inspect: <Result.Result<42, never>, void>(fn: (a: 42) => void) => (result: Result.Result<42, never>) => Result.Result<42, never> (+1 overload) inspect ((value: 42 value ) => var console: ConsoleThe 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 ('Debug:', value: 42 value )),
);
// Console output: "Debug: 42"
// Result: { type: 'Success', value: 42 }import { import Result Result } from '@praha/byethrow';
const const result: Result.Result<never, "error"> result = import Result Result .const pipe: <Result.Result<never, "error">, Result.Result<never, "error">>(a: Result.Result<never, "error">, ab: (a: Result.Result<never, "error">) => Result.Result<never, "error">) => Result.Result<never, "error"> (+25 overloads) pipe (
import Result Result .const fail: <"error">(error: "error") => Result.Result<never, "error"> (+1 overload) fail ('error'),
import Result Result .const inspect: <Result.Result<never, "error">, void>(fn: (a: never) => void) => (result: Result.Result<never, "error">) => Result.Result<never, "error"> (+1 overload) inspect ((value: never value ) => var console: ConsoleThe 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 ('Debug:', value: never value )),
);
// No console output
// Result: { type: 'Failure', error: 'error' }#See
pipe - It is recommended to use this function with the pipe function for better readability and composability.
#Call Signature
inspect<
R1,R2>(fn): (result) =>ResultFor<R1|R2,InferSuccess<R1>,InferFailure<R1>>
#Type Parameters
#R1
R1 extends ResultMaybeAsync<any, any>
#R2
R2
#Parameters
#fn
(a) => R2
#Returns
(result) => ResultFor<R1 | R2, InferSuccess<R1>, InferFailure<R1>>
#Call Signature
inspect<
F>(fn): <R1>(result) =>ResultFor<R1|ReturnType<F>,InferSuccess<R1>,InferFailure<R1>>
#Type Parameters
#F
F extends (a) => unknown
#Parameters
#fn
F
#Returns
<R1>(result) => ResultFor<R1 | ReturnType<F>, InferSuccess<R1>, InferFailure<R1>>
