# Function

`import { Function } from "destack:types";`

Callable value type, repeatable by default and affine when invoked once.

```ds title="Function"
export newtype Function<Parameters: readonly (...unknown[],) = (), Return = unknown, const M: Multiplicity = "repeatable"> = intrinsic
```

[language/library/src/types/function.ds:6:10](https://github.com/destack-sh/destack/blob/main/language/library/src/types/function.ds#L6-L10)