The 'return-from' special form allows the return of an arbitrary value at arbitrary times within a 'named-block' construct of the specified 'name'. The 'expr' will be returned by the block construct. A NIL will be returned by the block construct if there is no 'expr' specified.
If 'return-from' is used without being within a valid block construct, an error is generated:
error: no target for RETURN
(block out                        ; outer BLOCK
  (print "outer")
  (block in                       ; inner BLOCK
    (print "inner")
    (return-from out "all done")
    (print "won't get here")))    ; prints "outer"
                                  ; prints "inner"
                                  ; returns "all done"
(return-from nobody 9)            ; error: no target for RETURN
See the
return-from
special form in the