assert
let assert: (_: bool) => unit
The call assert(cond) terminates the execution with the string
"failed assertion" if, and only if, the boolean condition cond
is false.
let some: <a>(_: option<a>) => unit
The call some(opt) terminates the execution with the
string "failed assert some" if, and only if, opt is None().
let none: <a>(_: option<a>) => unit
The call none(opt) terminates the execution with the string
"failed assert none" if, and only if, opt is not None().