I made precisely this suggestion to Matthias a week ago! I'd love to have this. <blockquote>On May 6, 2009 3:31 PM, "Doug Orleans" <<a href="mailto:dougorleans@gmail.com">dougorleans@gmail.com</a>> wrote: Scheme has a nice symmetry between arguments and return values. Procedures like make-do-sequence take advantage of this: instead of taking six arguments, it takes a thunk that returns six values, so that it can generate the six values fresh every time an iterator is created. I'm always forgetting the order of the values, though; if they were arguments, then make-do-sequence could use keyword arguments so you wouldn't have to remember the order. But return values can't include keywords: > (call-with-values (lambda () (values #:y 3 1)) (lambda (x #:y (y 2)) (list x y))) procedure application: expected a procedure that accepts keyword arguments, given #<procedure:values>; arguments were: 1 #:y 3 Would it be feasible to allow this? I think that would restore the symmetry between arguments and return values. --<a href="mailto:dougorleans@gmail.com">dougorleans@gmail.com</a> _________________________________________________ For list-related administrative tasks: <a href="http://list.cs.brown.edu/mailman/listinfo/plt-scheme" target="_blank">http://list.cs.brown.edu/mailman/listinfo/plt-scheme</a> </blockquote>