SRFI 227 is now in final status.This SRFI specifies the opt-lambda syntax, which generalizes lambda. An opt-lambda expression evaluates to a procedure that takes a number of required and a number of optional (positional) arguments whose default values are determined by evaluating corresponding expressions when the procedure is called. This SRFI also specifies a variation opt*-lambda, which is to opt-lambda as let* is to let and the related binding constructs let-optionals and let-optionals*. ...
