The answer is to use LOCAL-STORAGE in place of WORKING-STORAGE for the recursive routine. LOCAL-STORAGE is obtained on entry to the subprogram and is (as the name implies) local to the current CALL level.
Unfortunately, it also means the recursive part must be in a separately-compiled program, since as you researched recursive programs can't be nested in the implementations that we have. HTH Peter -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of John McKown Sent: Tuesday, July 30, 2013 9:46 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: COBOL ? - emulating recursive PERFORM statement I had a programmer as whether a PERFORM could be recursive. The answer is "No". I even tried to explain why. But he says that if he could do it, it would save some "really messy" coding. So I thought that I'd ask here if anyone has ever heard of a way to do something which would be similar to a recursive PERFORM. I've always heard that recursion can be replaced with a stack and iterative programming. But I've not come up with a way to do this, nicely, in COBOL. Perhaps that is the "messiness" to which the programmer was referring. Perhaps because COBOL doesn't implement stacks either. So a stack must be implemented with a array and a current-index-value variable, perhaps defined as INDEXED BY. I was looking into using nested programs which were recursive. But that turns out to not be possible. RECURSIVE programs can't have nested programs. And nested programs can't be RECURSIVE. -- This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
