* bug#6985: rx patterns don't compose
@ 2010-09-04 23:37 Daniel Colascione
2010-09-05 7:22 ` Stefan Monnier
2010-09-05 7:39 ` Andreas Schwab
0 siblings, 2 replies; 5+ messages in thread
From: Daniel Colascione @ 2010-09-04 23:37 UTC (permalink / raw)
To: 6985
It's not possible to do this currently:
(defconst foo-re (rx "abc"))
(defconst bar-re (rx (* (what-goes-here? foo-re)))
in any sensible way. This won't work
(defconst bar-re (rx (* (regexp foo-re))))
because regexp always expects a string.
This won't work, because eval always quotes its argument:
(defconst bar-re (rx (* (eval foo-re))))
I propose allowing regexp to accept a symbol as well as a string, and
using that symbol's value literally. Alternatively, rx could provide an
eval-unquoted facility. Or both.
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#6985: rx patterns don't compose
2010-09-04 23:37 bug#6985: rx patterns don't compose Daniel Colascione
@ 2010-09-05 7:22 ` Stefan Monnier
2010-09-05 7:39 ` Andreas Schwab
1 sibling, 0 replies; 5+ messages in thread
From: Stefan Monnier @ 2010-09-05 7:22 UTC (permalink / raw)
To: Daniel Colascione; +Cc: 6985
> It's not possible to do this currently:
> (defconst foo-re (rx "abc"))
> (defconst bar-re (rx (* (what-goes-here? foo-re)))
(defconst foo-re (rx "abc"))
(defconst bar-re `(rx (* (regexp ,foo-re)))
> in any sensible way. This won't work
> (defconst bar-re (rx (* (regexp foo-re))))
> because regexp always expects a string.
> This won't work, because eval always quotes its argument:
> (defconst bar-re (rx (* (eval foo-re))))
> I propose allowing regexp to accept a symbol as well as a string, and
> using that symbol's value literally. Alternatively, rx could provide an
> eval-unquoted facility. Or both.
eval-unquoted sounds OK
Stefan
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#6985: rx patterns don't compose
2010-09-04 23:37 bug#6985: rx patterns don't compose Daniel Colascione
2010-09-05 7:22 ` Stefan Monnier
@ 2010-09-05 7:39 ` Andreas Schwab
2010-09-05 7:42 ` Daniel Colascione
1 sibling, 1 reply; 5+ messages in thread
From: Andreas Schwab @ 2010-09-05 7:39 UTC (permalink / raw)
To: Daniel Colascione; +Cc: 6985
Daniel Colascione <dan.colascione@gmail.com> writes:
> It's not possible to do this currently:
>
> (defconst foo-re (rx "abc"))
> (defconst bar-re (rx (* (what-goes-here? foo-re)))
(defconst bar-re (eval `(rx (* (regexp ,foo-re))))
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#6985: rx patterns don't compose
2010-09-05 7:39 ` Andreas Schwab
@ 2010-09-05 7:42 ` Daniel Colascione
2010-09-05 10:45 ` Andreas Schwab
0 siblings, 1 reply; 5+ messages in thread
From: Daniel Colascione @ 2010-09-05 7:42 UTC (permalink / raw)
To: Andreas Schwab; +Cc: 6985
On 9/5/10 12:39 AM, Andreas Schwab wrote:
> Daniel Colascione <dan.colascione@gmail.com> writes:
>
>> It's not possible to do this currently:
>>
>> (defconst foo-re (rx "abc"))
>> (defconst bar-re (rx (* (what-goes-here? foo-re)))
>
> (defconst bar-re (eval `(rx (* (regexp ,foo-re))))
Or better yet,
(defconst bar-re (rx-to-string `(* (regexp ,foo-re))))
But it's still cumbersome.
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#6985: rx patterns don't compose
2010-09-05 7:42 ` Daniel Colascione
@ 2010-09-05 10:45 ` Andreas Schwab
0 siblings, 0 replies; 5+ messages in thread
From: Andreas Schwab @ 2010-09-05 10:45 UTC (permalink / raw)
To: Daniel Colascione; +Cc: 6985
Daniel Colascione <dan.colascione@gmail.com> writes:
> (defconst bar-re (rx-to-string `(* (regexp ,foo-re))))
To avoid the extra group:
(defconst bar-re (rx-to-string `(* (regexp ,foo-re)) t))
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2010-09-05 10:45 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2010-09-04 23:37 bug#6985: rx patterns don't compose Daniel Colascione
2010-09-05 7:22 ` Stefan Monnier
2010-09-05 7:39 ` Andreas Schwab
2010-09-05 7:42 ` Daniel Colascione
2010-09-05 10:45 ` Andreas Schwab
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