error

let assert: (_: bool) => (_: string) => unit

The call assert(cond, error) terminates the execution with the string error (that is, an error message) if, and only if, the boolean condition cond is false.

let some: <a>(_: option<a>) => (_: string) => unit

The call some(opt, err) terminates the execution with the string err (that is, an error message) if, and only if, opt is None().

let none: <a>(_: option<a>) => (_: string) => unit

The call none(opt, err) terminates the execution with the string err (that is, an error message) if, and only if, opt is an optional value different from None().