- (maybe-and expr ...)syntax
- (either-and expr ...)syntax
The exprs are evaluated in order. If an expr evaluates to a Nothing / Left, it is returned without evaluating any more expressions. Otherwise, the last Just / Right is returned. If there are no exprs, then a Just/Right of an unspecified value is returned. If an expr does not evaluate to a Maybe/Either, an error satisfying error-object is signaled.