> For the complete documentation index, see [llms.txt](https://osl.mistium.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://osl.mistium.com/standard-library/utilities/result.md).

# result

Use `result` to return either a success value or an error value from APIs that should not throw immediately.

`result` is a built-in language type. It needs no package import.

## Example

```osl
auto ok = result.ok(42)
log ok.unwrapOr(0)
```

## API reference

### `result`

| Method               | Returns  |
| -------------------- | -------- |
| `result.ok(v: any)`  | `result` |
| `result.err(e: any)` | `result` |

### `result` values

Methods available on `result` values constructed by the language or returned by APIs. An unparameterized `result` preserves success and error values as `any`. A `result<T>` keeps the success type and defaults its error accessor to `string`; use `result<T, E>` to specify both sides.

| Method                               | Returns   | Notes                                                            |
| ------------------------------------ | --------- | ---------------------------------------------------------------- |
| `value.isOk()`                       | `boolean` |                                                                  |
| `value.isErr()`                      | `boolean` |                                                                  |
| `value.unwrap()`                     | `any`     | Returns the success value, or fails for an error result.         |
| `value.unwrapOr(def: any)`           | `any`     | Returns the contained value or a fallback.                       |
| `value.expect(msg: any)`             | `any`     | Returns the contained value or fails with a custom message.      |
| `value.unwrapErr()`                  | `any`     | Returns the error value, or fails for a success result.          |
| `value.expectErr(msg: any)`          | `any`     | Uses the same error-side accessor with a custom failure message. |
| `value.fromGo(val: any, err: error)` | `result`  | Creates from go.                                                 |