return-from name [result] →|

name — a block tag; not evaluated.

result — a form; evaluated. The default is nil.

Returns control and multiple values₂ from a lexically enclosing block.

A block form named name must lexically enclose the occurrence of return-from; any values yielded by the evaluation of result are immediately returned from the innermost such lexically enclosing block.

The transfer of control initiated by return-from is performed as described in Section 5.2 (Transfer of Control to an Exit Point).

 (block alpha (return-from alpha) 1) → NIL 
 (block alpha (return-from alpha 1) 2) → 1 
 (block alpha (return-from alpha (values 1 2)) 3) → 1, 2 
 (let ((a 0)) 
    (dotimes (i 10) (incf a) (when (oddp i) (return))) 
    a) → 2 
 (defun temp (x) 
    (if x (return-from temp 'dummy)) 
    44) → TEMP 
 (temp nil) → 44 
 (temp t) → DUMMY 
 (block out 
   (flet ((exit (n) (return-from out n))) 
     (block out (exit 1))) 
   2) → 1 
 (block nil 
   (unwind-protect (return-from nil 1) 
     (return-from nil 2))) 
→ 2 
 (dolist (flag '(nil t)) 
   (block nil 
     (let ((x 5)) 
       (declare (special x)) 
       (unwind-protect (return-from nil) 
         (print x)))) 
   (print 'here)) 
⊳ 5 
⊳ HERE 
⊳ 5 
⊳ HERE 
→ NIL 
 (dolist (flag '(nil t)) 
   (block nil 
     (let ((x 5)) 
       (declare (special x)) 
       (unwind-protect 
           (if flag (return-from nil)) 
         (print x)))) 
   (print 'here)) 
⊳ 5 
⊳ HERE 
⊳ 5 
⊳ HERE 
→ NIL

The following has undefined consequences because the block form exits normally before the return-from form is attempted.

(funcall (block nil #'(lambda () (return-from nil)))) is an error.

block, return, Section 3.1 (Evaluation)