Function err

err<E extends string = string, S = Error>(label: E, source?: S): ResultErr<E, S>
Creates a ResultErr. It can be called with a label and source, or with an existing Err object.
Type Parameters
- E extends string = string
  A string literal type for the error label.
- S = Error
  The type of the source error.
Parameters
- label: E
  The error label.
- Optionalsource: S
  The source of the error. If not provided, a new Error with the label as the message will be created.
Returns ResultErr<E, S>
A ResultErr.
Example
```
const [error, value] = err("not_found");
// error is { label: "not_found", source: Error("not_found") }
// value is null
```
Example
```
const [error, value] = err("not_found", new Error("Resource not found"));
// error is { label: "not_found", source: Error("Resource not found") }
// value is null
```
- Defined in result.ts:105