* pcase without code duplication
@ 2021-04-23 2:45 michael-franzese
2021-04-23 3:24 ` Óscar Fuentes
0 siblings, 1 reply; 5+ messages in thread
From: michael-franzese @ 2021-04-23 2:45 UTC (permalink / raw)
To: Help Gnu Emacs
I am using pcase, but am wondering whether I can have pcase
for 0 and 2 do the same things without adding a separate pcase
(0 and duplicating the statements.
(pcase orthogr-region
(0 ... ) ; same operations as pcase 2
(1 ... )
(2 ... ) ; operations
(_ ... ) )
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: pcase without code duplication
2021-04-23 2:45 pcase without code duplication michael-franzese
@ 2021-04-23 3:24 ` Óscar Fuentes
2021-04-23 3:45 ` michael-franzese
2021-04-23 3:51 ` [External] : " Drew Adams
0 siblings, 2 replies; 5+ messages in thread
From: Óscar Fuentes @ 2021-04-23 3:24 UTC (permalink / raw)
To: help-gnu-emacs
michael-franzese@gmx.com writes:
> I am using pcase, but am wondering whether I can have pcase
> for 0 and 2 do the same things without adding a separate pcase
> (0 and duplicating the statements.
>
> (pcase orthogr-region
> (0 ... ) ; same operations as pcase 2
> (1 ... )
> (2 ... ) ; operations
> (_ ... ) )
(let ((xx 2))
(pcase xx
(1 (message "one"))
((or 0 2) (message "zero or two"))
(_ (message "something else"))))
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: pcase without code duplication
2021-04-23 3:24 ` Óscar Fuentes
@ 2021-04-23 3:45 ` michael-franzese
2021-04-23 4:01 ` Stefan Monnier
2021-04-23 3:51 ` [External] : " Drew Adams
1 sibling, 1 reply; 5+ messages in thread
From: michael-franzese @ 2021-04-23 3:45 UTC (permalink / raw)
To: Óscar Fuentes; +Cc: help-gnu-emacs
Can one also use nil as option in pcase. What possibilities
exist for (_ ?
e.g.
(nil
((or 0 nil)
((or _ nil)
Regards
Michael
> Sent: Friday, April 23, 2021 at 3:24 PM
> From: "Óscar Fuentes" <ofv@wanadoo.es>
> To: help-gnu-emacs@gnu.org
> Subject: Re: pcase without code duplication
>
> michael-franzese@gmx.com writes:
>
> > I am using pcase, but am wondering whether I can have pcase
> > for 0 and 2 do the same things without adding a separate pcase
> > (0 and duplicating the statements.
> >
> > (pcase orthogr-region
> > (0 ... ) ; same operations as pcase 2
> > (1 ... )
> > (2 ... ) ; operations
> > (_ ... ) )
>
> (let ((xx 2))
> (pcase xx
> (1 (message "one"))
> ((or 0 2) (message "zero or two"))
> (_ (message "something else"))))
>
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: pcase without code duplication
2021-04-23 3:45 ` michael-franzese
@ 2021-04-23 4:01 ` Stefan Monnier
0 siblings, 0 replies; 5+ messages in thread
From: Stefan Monnier @ 2021-04-23 4:01 UTC (permalink / raw)
To: help-gnu-emacs
> Can one also use nil as option in pcase. What possibilities
> exist for (_ ?
>
> e.g.
>
> (nil
If you want to match a symbol, you need to quote it:
('nil (do-something))
> ((or 0 nil)
((or 0 'nil) (do-something-else))
Of course, you can also quote the 0 if you want, tho it makes no difference.
> ((or _ nil)
This is redundant, but yes you can do
((or _ 'nil) (do-yet-another-thing))
-- Stefan
^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: [External] : Re: pcase without code duplication
2021-04-23 3:24 ` Óscar Fuentes
2021-04-23 3:45 ` michael-franzese
@ 2021-04-23 3:51 ` Drew Adams
1 sibling, 0 replies; 5+ messages in thread
From: Drew Adams @ 2021-04-23 3:51 UTC (permalink / raw)
To: Óscar Fuentes, help-gnu-emacs@gnu.org
> > I am using pcase, but am wondering whether I can have pcase
> > for 0 and 2 do the same things without adding a separate pcase
> > (0 and duplicating the statements.
> >
> > (pcase orthogr-region
> > (0 ... ) ; same operations as pcase 2
> > (1 ... )
> > (2 ... ) ; operations
> > (_ ... ) )
>
> (let ((xx 2))
> (pcase xx
> (1 (message "one"))
> ((or 0 2) (message "zero or two"))
> (_ (message "something else"))))
And even ordinary cl-case (aka case) will do,
if that's all you're doing.
(cl-case xx
(1 (message "one"))
((0 2) (message "zero or two"))
(t (message "something else")))
^ permalink raw reply [flat|nested] 5+ messages in thread
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2021-04-23 2:45 pcase without code duplication michael-franzese
2021-04-23 3:24 ` Óscar Fuentes
2021-04-23 3:45 ` michael-franzese
2021-04-23 4:01 ` Stefan Monnier
2021-04-23 3:51 ` [External] : " Drew Adams
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