David,

Understood. I use REXX extensively for ISPF edit macros and such. I was 
agreeing that there were some "nice to have things" which clist did have. When 
I started, clist was the only way to go. Once we were introduced to REXX, I 
began converting clists to EXECs, and found WRITENR was a "clist only" entity. 
I agree with others in that the clist "PROC" could have been useful in REXX. I 
suspect most of us have written some sort of general-purpose parsing logic for 
use in REXX.

At this point, I have only a handful of clists which are still in use. Most are 
"1 time only" type things and are not worth converting.

Bill Hitefield
Dino-Software Corporation
800.480.DINO
www.dino-software.com

> -----Original Message-----
> From: IBM Mainframe Discussion List <[email protected]> On
> Behalf Of David Spiegel
> Sent: Thursday, January 9, 2025 7:26 PM
> To: [email protected]
> Subject: Re: ISREDIT CAPS ON OFF
> 
> Hi Bill,
> I also have an Exec which calls my Writenr clist.. My point was counter the
> idea that with Rexx, CLISTs are never necessary.
> 
> Regards,
> David
> 
> On 2025-01-09 19:18, Bill Hitefield wrote:
> > I wrote a dinky CLIST to issue WRITENR. I call it from REXX as needed.
> >
> > Bill Hitefield
> >
> >> -----Original Message-----
> >> From: IBM Mainframe Discussion List <[email protected]> On
> >> Behalf Of David Spiegel
> >> Sent: Thursday, January 9, 2025 5:42 PM
> >> To: [email protected]
> >> Subject: Re: ISREDIT CAPS ON OFF
> >>
> >> Hi Tony,
> >> CLISTs also have the WRITENR statement, which Rexx lacks.
> >>
> >> Regards,.
> >> David
> >>
> >> On 2025-01-09 16:49, Tony Harminc wrote:
> >>> On Wed, 8 Jan 2025 at 19:51, Lennie Bradshaw
> >>> <[email protected]>
> >>> wrote:
> >>>
> >>>> CLIST design is over 50 years old I think.
> >>>>
> >>> CLISTs as we know them arrived with OS VS/2 Release 3, so the second
> >>> release of MVS around 1974 or so. Before that, on e.g MVT, SVS, and
> >>> the first MVS, CLISTs had no control flow statements - they were
> >>> just lists of commands with some substitution for arguments.
> >>>
> >>> At introduction, everyone was all excited at the shiny new CLISTs,
> >>> and I remember well wondering why there was no lower case support,
> >>> and if it could be easily fixed. Indeed it could, and I found and
> >>> happily zapped out the upcasing and tried a CLIST with some lower
> >>> case text in it. It blew up all over the place, and I discovered
> >>> that pretty much all byte values beyond the upper case letters,
> >>> numbers, and a few more (i.e. roughly the JCL character set at the
> >>> time) was being used as internal syntactic markers for various
> >>> aspects of the language. So much for
> >> that quick fix.
> >>> No, I don't remember the details, but I imagine much of today's
> >>> CLIST processor is unchanged from the 1970s version, and the source
> >>> code for that is available if anyone wants to research it further.
> >>>
> >>> But seriously, why does anyone use CLISTs today? There is to my
> >>> knowledge just one reason: there is tight integration with TSO
> >>> parsing and the CLIST header, whereas REXX requires that the command
> >>> be treated as a single string, and then parsed with the (unarguably
> >>> powerful)
> >> REXX parsing scheme.
> >>> But that doesn't allow for a syntax error to be discovered in the
> >>> REXX and the user prompted using TSO facilities; the REXX has to do
> >>> all the work itself.
> >>>
> >>> Tony H.
> >>>
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