Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!jpl-devvax!lwall
From: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Newsgroups: comp.lang.perl
Subject: Re: grep as apply (was Re: <HANDLE> = @array?)
Message-ID: <7158@jpl-devvax.JPL.NASA.GOV>
Date: 23 Feb 90 22:03:42 GMT
References: <15193@bfmny0.UU.NET> <100197@convex.convex.com> <1990Feb23.190455.2653@iwarp.intel.com>
Reply-To: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 27

In article <1990Feb23.190455.2653@iwarp.intel.com> merlyn@iwarp.intel.com (Randal Schwartz) writes:
: In article <100197@convex.convex.com>, tchrist@convex (Tom Christiansen) writes:
: | 	@array += 3;
: | 
: | is nice (and I don't even know APL :-) but also unnecessary since you
: | can always use:
: | 
: | 	grep($_ += 3, @array);
: 
: Ahem.
: 
: 	grep($_ += 3 || 1, @array);
: 
: or you have just lost your zero elements.  Remember, grep is both
: apply *and* select.  Get that idiom *down*!

Er, note that he's adding to @array in place.  The selection only applies
to the returned array value.  If he'd said

 	@array = grep($_ += 3, @array);

then you'd be righter.

: $,=' ';print grep(s/^.//, sort "2another","4hacker,","1Just","3Perl");

Pushed another Hal jerker,
Larry