block

Type:	-	special form (fsubr)
Source:	-	xlcont.c

Syntax

Description

The 'block' special form specifies a 'named block' construct. The last expression in 'body' will be returned by the 'block' construct as its result unless a return or return-from is executed within 'block'. The return exit will exit the nearest [inner-most] 'block'. The return-from exit will exit the specified 'block'.

Examples

(defun test ()
  (block outer         ; outer BLOCK
    (print "outer")
    (block inner       ; inner BLOCK
      (print "inner")
      (return-from outer "all done")
      (print "won't get here"))))

> (test)
"outer"     ; screen output of PRINT
"inner"     ; screen output of PRINT
"all done"  ; return value

See defun, print, return-from.

See also:

• Contents → Control Constructs

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