PRIMITIVE FOR NON-RECURSIVE LIST PROCESSING.

A new LISP primitive rcons (reverse cons) is proposed, which can be used to transform a certain type of recursively defined function into iterative ones. Rcons, which constructs a list in the reverse order (i. e. , from head to tail), could be defined in terms of rplacd and cons. However, as a new primitive instead of a composite function, rcons can dispose of overheads in space and time due to rplacd, used inside the composite rcons, in cdr-coding implementations.