Class Err<E>

Creates an Err.

Example

const errorResult = new Err('Something went wrong');
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Returns a Result. If this Result is an Err, the function returns this Result.

Example

const errorResult = new Err('Something went wrong');
const anotherResult = new Ok(42);
const combined = errorResult.and(anotherResult); // combined is errorResult
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Returns a new Result that is the result of applying the given function to the value of this Result. If this Result is an Err, the function is not applied and the error is returned.

Example

const errorResult = new Err('Something went wrong');
const newResult = errorResult.andThen(value => new Ok(value)); // newResult is errorResult
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Returns true if this Result is an Err, false otherwise.

Example

const errorResult = new Err('Something went wrong');
console.log(errorResult.isError()); // true
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Returns true if this Result is an Err, false otherwise.

Example

const errorResult = new Err('Something went wrong');
console.log(errorResult.isOk()); // false
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Returns a new Result that is the result of applying the given function to the value of this Result. If this Result is an Err, the function is not applied and the error is returned.

Example

const errorResult = new Err('Something went wrong');
const mappedResult = errorResult.map(value => value.toString()); // mappedResult is errorResult
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Returns a new Result that is the result of applying the given function to the error of this Result. If this Result is an Err, the function is applied to the error.

Example

const errorResult = new Err('Something went wrong');
const newErrorResult = errorResult.mapError(error => 'New error'); // newErrorResult is Err('New error')
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Throws an error as this Result is an Err.

Throws

Always throws an error as this Result is an Err.

Example

const errorResult = new Err('Something went wrong');
errorResult.unwrap(); // throws Error
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Returns the error of this Result.

Example

const errorResult = new Err('Something went wrong');
console.log(errorResult.unwrapError()); // 'Something went wrong'
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Returns the default value as this Result is an Err.

Example

const errorResult = new Err('Something went wrong');
console.log(errorResult.unwrapOr(42)); // 42
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