From: Peter Stephenson <pws@ibmth.df.unipi.it>
To: zsh-workers@sunsite.auc.dk
Subject: Re: PATCH: new parameter expansion type?
Date: Mon, 30 Aug 1999 18:10:45 +0200 [thread overview]
Message-ID: <9908301610.AA17542@ibmth.df.unipi.it> (raw)
In-Reply-To: ""Bart Schaefer""'s message of "Mon, 30 Aug 1999 16:05:58 DFT." <990830160558.ZM6355@candle.brasslantern.com>
"Bart Schaefer" wrote:
> On Aug 30, 11:49am, Sven Wischnowsky wrote:
> } Subject: PATCH: new parameter expansion type?
> }
> } ${name^pattern^then^else}
> }
> } Gives you the (substituted) `then' string if the expansion of `name'
> } matches the `pattern' and otherwise it gives you the `else' string.
>
> Isn't this just the same as
>
> ${${${(M)name#pattern}:+then}:-else}
>
> except of course that you have to be a little selective about whether
> you use # or % to delimit the pattern?
This seems to be the case; I've included it in 6-pws-2, but I'll probably
back it off in 6-pws-3, unless there's a good reason otherwise.
I was thinking about a more general ternary expression syntax, which would
require doing some work to pre-expansion argument lists. Something like
${[[ <test> ]] <true1> <true2> ... | <false1> <false2> ... }
i.e. the true/false bits are treated like part of an ordinary argument list
(but can't have redirections). I suspect it's going to be too clumsy,
however. You can get the same effect with if's and arrays, obviously.
--
Peter Stephenson <pws@ibmth.df.unipi.it> Tel: +39 050 844536
WWW: http://www.ifh.de/~pws/
Dipartimento di Fisica, Via Buonarroti 2, 56127 Pisa, Italy
next prev parent reply other threads:[~1999-08-30 16:44 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-08-30 9:49 Sven Wischnowsky
1999-08-30 10:06 ` Andrej Borsenkow
1999-08-30 10:58 ` Tanaka Akira
1999-08-30 16:05 ` Bart Schaefer
1999-08-30 16:10 ` Peter Stephenson [this message]
1999-08-30 10:38 Sven Wischnowsky
1999-08-31 13:18 ` Andrej Borsenkow
1999-08-31 8:50 Sven Wischnowsky
1999-08-31 17:47 ` Bart Schaefer
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