> Conscientious documentation of Rexx avoid the word
> "default" in this context for two reasons:
> `1. The expression is assigned to the stem with every
> possible tail, not to only those not previously given
> a value.
Not so; ooRexx is not SAA rex. The ooRexx documentation uses the word default
because it *is* appropriate in the context of ooRexx.
> 2. If an individual member of the compound is DRO ped,
> its value returns to the standard UPPER(stem.tail), not
> the value assigned earlier to the stem.
That's because DROP does not set a compound variable to the default value of
the stem.
The test below is from OREXX rather than ooRexx, but the results should be the
same.
Tue 7-02-24 12:56:11{2}[h:\] rexxtry
REXXTRY.CMD lets you interactively try REXX statements.
Each string is executed when you hit Enter.
Enter 'call tell' for a description of the features.
Go on - try a few... Enter 'exit' to end.
foo.=bar
................................................ REXXTRY.CMD on OS/2
drop foo.baz
................................................ REXXTRY.CMD on OS/2
say foo.baz
FOO.BAZ
................................................ REXXTRY.CMD on OS/2
say foo.foo
BAR
................................................ REXXTRY.CMD on OS/2
say foo.~makearray
an Array
................................................ REXXTRY.CMD on OS/2
say foo.~makearray~items
0
................................................ REXXTRY.CMD on OS/2
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
עַם יִשְׂרָאֵל חַי
נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר
________________________________________
From: IBM Mainframe Discussion List <[email protected]> on behalf of
Paul Gilmartin <[email protected]>
Sent: Tuesday, July 2, 2024 12:09 PM
To: [email protected]
Subject: Re: Rexx is quite cool, flexible, powerful, feature-rich, thank you!
(Re: z/OS 3.1 Enhancements & Support News
On Tue, 2 Jul 2024 15:24:29 +0000, Seymour J Metz wrote:
>> I notice you didn't discuss;
>>> A. = 'Preset'
>> > drop A.GAP
>
>Because neither has an effect on the loop.
>
>> Further, when a stem is used as the target of an assignment,
>> all possible compound variables whose names begin
> > with that stem receive the new value,
>
>That text is for TSO/E (classic) REXX, not for ooRexx.
>
Yes, that's where I found it.
>> Or do I fail to understand that in oo the first instruction
>> replaces the compound symbol with a single string
>> object; leaving no members to DROP?
>
>No, is sets the object name and default value.
>
Conscientious documentation of Rexx avoid the word
"default" in this context for two reasons:
`1. The expression is assigned to the stem with every
possible tail, not to only those not previously given
a value.
2. If an individual member of the compound is DRO ped,
its value returns to the standard UPPER(stem.tail), not
the value assigned earlier to the stem.
Both CMS REXX and TSO/E REXX have at various times
broken the second rule by service, and I needed to open
APARs to repair them. I suspect the motivation for the
disservice was performance.
Which "default" does ooRexx use after assignment to a
stem and DROPping an individual member?
>"If the new value is not a Stem object, a new Stem object is created and
>assigned to
>the stem variable, replacing the Stem object currently associated with the
>stem variable.
>The new value assigned to the stem variable is given to the new Stem object as
>a default value.
>Following the assignment, a reference to any compound symbol with that stem
>variable
>returns the new value until another value is assigned to the stem, the Stem
>object,
>or the individual compound variable."
>________________________________________
>From: Paul Gilmartin
>Sent: Tuesday, July 2, 2024 10:38 AM
>
>On Tue, 2 Jul 2024 01:51:36 +0000, Seymour J Metz wrote:
>
>>do i over A.
>> say 'A.'i '=' A.i
>> end
>>
>>Shouldggive only one line: "A. = I dunno".
>>
>I notice you didn't discuss;
>> A. = 'Preset'
>> drop A.GAP
>
><https://www.ibm.com/docs/en/zos/3.1.0?topic=symbols-stems>
> Further, when a stem is used as the target of an assignment,
> all possible compound variables whose names begin
> with that stem receive the new value,
>
>Or do I fail to understand that in oo the first instruction
>replaces the compound symbol with a single string
>object; leaving no members to DROP?
>
>>________________________________________
>>From: Paul Gilmartin
>>Sent: Monday, July 1, 2024 8:32 PM
>>
>>What does DO OVER do for the analogue of REXX:
>> A. = 'Preset'
>> drop A.GAP
>> Null = ''; A.Null = "I dunno"
>>???
--
gil
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