As Martin previously mentioned some languages implement proper tail
calls so they effectively turn recursion into iteration
https://www.lua.org/pil/6.3.html.
This is a great optimization as recursion is often the most elegant
method to implement many data structures and algorithms (quicksort,
binary trees etc).
On 2020-04-09 12:40 AM, Frank Swarbrick wrote:
Yes, very verbose.
And yes, recursion is possible, but you must specify "IS RECURSIVE" on the
PROGRAM-ID. Not sure what having nested programs has to do with that, though.
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From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of David
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Sent: Tuesday, April 7, 2020 7:44 PM
To: IBM-MAIN@LISTSERV.UA.EDU <IBM-MAIN@LISTSERV.UA.EDU>
Subject: Re: Why rip out COBOL when you can modernize key applications? -
Weirdware
Wow, and some people criticize Java for being verbose!
So using nested programs one can implement recursion in COBOL which you
couldn't do before without using a table stack.
On 2020-04-08 5:14 AM, Frank Swarbrick wrote:
Nested subroutines.
Small example:
ID DIVISION.
PROGRAM-NAME. MAINPROG.
[...]
PROCEDURE DIVISION.
CALL 'NESTED-PROGRAM-1'
GOBACK.
ID DIVISION.
PROGRAM-ID. NESTED-PROGRAM-1.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 LOCAL-VAR-1 PIC X.
[...]
PROCEDURE DIVISION.
DISPLAY 'IN NESTED-PROGRAM-1'
GOBACK.
END PROGRAM NESTED-PROGRAM-1.
END PROGRAM MAINPROG.
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From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of David
Spiegel <dspiegel...@hotmail.com>
Sent: Tuesday, April 7, 2020 2:58 PM
To: IBM-MAIN@LISTSERV.UA.EDU <IBM-MAIN@LISTSERV.UA.EDU>
Subject: Re: Why rip out COBOL when you can modernize key applications? -
Weirdware
Hi Frank,
Thank you for that information.
(All the COBOL I support(ed) didn't contain these and neither did my
university courses in the '70s.)
If I wanted to look them up, which keyword(s) would I use?
Thanks and regards,
David
On 2020-04-07 15:49, Frank Swarbrick wrote:
Internal subroutines and local variables have been supported since COBOL 1985
(VS COBOL II era).
They're not ideal, but they do exist.
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From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of David
Spiegel <dspiegel...@hotmail.com>
Sent: Tuesday, April 7, 2020 12:58 PM
To: IBM-MAIN@LISTSERV.UA.EDU <IBM-MAIN@LISTSERV.UA.EDU>
Subject: Re: Why rip out COBOL when you can modernize key applications? -
Weirdware
How about no internal subroutines with local variables?
On 2020-04-07 14:47, Bob Bridges wrote:
I used to bad-mouth COBOL, and I still prefer languages that are less wordy. But I came
somewhat reluctantly to see that it has its strengths. The one I think most important is
that it encourages even novice programmers to organize their logic in what we used to
call a "top-down" manner: This paragraph accomplish a certain task by
executing paragraphs one through three, then two more, and this subparagraph executes
subsubparagraphs, and so on. Forms good habits, I think.
---
Bob Bridges, robhbrid...@gmail.com, cell 336 382-7313
/* My life is in the hands of any fool who can make me lose my temper.
-driving motto */
-----Original Message-----
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf
Of scott Ford
Sent: Tuesday, April 7, 2020 12:55
I learned Assembler first and then Cobol and then some PL/1. I always felt
each language had its strengths and weaknesses and all were like tools in a
toolbox.
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