error

let assert: (b: bool, s: 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. The failure is handled by LIGO's testing framework and not by Michelson's interpreter.

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(). The failure is handled by LIGO's testing framework and not by Michelson's interpreter.

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(). The failure is handled by LIGO's testing framework and not by Michelson's interpreter.