For simple editing commands, numbered back references are very convenient, but
for complicated parsing it becomes difficult to keep track of who did what to
whom; at that point named captures are crucial. I use both. Alas, the regex
syntax in TSPF is not the same as in ISPF, neither is the same as in Perl, ...
As George Mealy said: "Standards are wonderful things; everyone should have one
of their own."
Stems are good; use the same stem for numbered and named captures.
/(\d+) \s+ (foo=(?<FOO>[abc]+)|bar=(?<BAR>[def]+) \s/i
would populate stem.1, stem.2 and either stem.FOO or stem.BAR.
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
________________________________________
From: IBM Mainframe Assembler List [[email protected]] on behalf
of Paul Gilmartin [[email protected]]
Sent: Tuesday, February 22, 2022 10:03 PM
To: [email protected]
Subject: Re: Interpreting Explicit Decimal Numbers
On Feb 22, 2022, at 18:59:06, Seymour J Metz wrote:
>
> Back-references are certainly essential, but for complicated expressions
> assertions, named captures, etc., make life easier.
>
For substituting in a string, as in sed or vi, numbered back-references
Work well enough. Otherwise the programmer needs to define labels.
For assignment to variables names are proper. But how about supplying
a stem and letting regex assign to numbered members? The programmer
might supply synonyms, as in SYSCALL_CONSTANTS.
ISPF Edit Change should allow replacement strings containing
back-references.
> ________________________________________
> From: Paul Gilmartin
> Sent: Tuesday, February 22, 2022 12:37 PM
>
> I'd be reasonably satisfied with POSIX ERE and back-references optionally
> assigned to Rexx variables.
>
> --
> gil
--
gil
