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Reverse

Reverse a list or string

(Reverse x) is the result of reversing the order of the elements of the list or string x.

The guard for reverse requires that its argument is a true list or a string.

Reverse is defined in Common Lisp. See any Common Lisp documentation for more information.

Function: reverse

(defun reverse (x)
  (declare (xargs :guard (or (true-listp x) (stringp x))))
  (cond ((stringp x)
         (coerce (revappend (coerce x 'list) nil)
                 'string))
        (t (revappend x nil))))

Subtopics

Nrev
A safe mechanism for implementing something like nreverse, for writing tail-recursive functions that use less memory by avoiding the final reverse step.
Rev
Logically simple alternative to reverse for lists.
Std/lists/reverse
Lemmas about reverse available in the std/lists library.
Hons-reverse
REVERSE using HONS instead of CONS