Function mapErr

mapErr<R extends UnknownTernaryResult, E2>(
result: R,
mapFn: (error: UnwrapErr<R>) => E2,
): TernaryResult<UnwrapOk<R>, E2, UnwrapWarn<R>>
Maps the Err variant while leaving Ok/Warn untouched.
Type Parameters
- R extends UnknownTernaryResult
- E2
Parameters
- result: R
- mapFn: (error: UnwrapErr<R>) => E2
Returns TernaryResult<UnwrapOk<R>, E2, UnwrapWarn<R>>
Example
```
const errValue = TernaryResult.err('boom');

const mappedErr = TernaryResult.mapErr(errValue, (error) =>
  error.toUpperCase(),
);

const warnPassthrough = TernaryResult.mapErr(
  TernaryResult.warn(2, 'slow'),
  (error: string) => `${error}!`,
);

assert.deepStrictEqual(mappedErr, TernaryResult.err('BOOM'));

assert.deepStrictEqual(warnPassthrough, TernaryResult.warn(2, 'slow'));
```
- Defined in src/functional/ternary-result/impl/ternary-result-map-err.mts:27

mapErr<E, E2>(
mapFn: (error: E) => E2,
): <S, W>(result: TernaryResult<S, E, W>) => TernaryResult<S, E2, W>

Maps the Err variant while leaving Ok/Warn untouched.

Type Parameters

Parameters

mapFn: (error: E) => E2

Returns <S, W>(result: TernaryResult<S, E, W>) => TernaryResult<S, E2, W>

Example

const errValue = TernaryResult.err('boom');

const mappedErr = TernaryResult.mapErr(errValue, (error) =>
  error.toUpperCase(),
);

const warnPassthrough = TernaryResult.mapErr(
  TernaryResult.warn(2, 'slow'),
  (error: string) => `${error}!`,
);

assert.deepStrictEqual(mappedErr, TernaryResult.err('BOOM'));

assert.deepStrictEqual(warnPassthrough, TernaryResult.warn(2, 'slow'));

Function mapErr

Type Parameters

Parameters

Returns TernaryResult<UnwrapOk<R>, E2, UnwrapWarn<R>>

Example

Type Parameters

Parameters

Returns <S, W>(result: TernaryResult<S, E, W>) => TernaryResult<S, E2, W>

Example

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