Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!sun-barr!newstop!texsun!convex!convex.com!tchrist
From: tchrist@convex.com (Tom Christiansen)
Newsgroups: comp.lang.perl
Subject: inlining your sort subroutine
Message-ID: <109155@convex.convex.com>
Date: 22 Nov 90 16:11:14 GMT
Sender: news@convex.com
Reply-To: tchrist@convex.com (Tom Christiansen)
Organization: Convex Computer Corp, Richardson, TX
Lines: 50

Instead of having to doing this:

    sub numerically { $a <=> $b; }
    @out = sort numerically @in;

wouldn't this be nice:

    @out = sort { $a <=> $b; } @in;

You can *almost* do it right now.

    $func = 'func0001';
    sub makefun { eval "sub $func { $_[0]; }"; $func++; } 

    $f1 = &makefun('print "hello $a\n"');
    $f2 = &makefun('$a++');

    for (1..3) {
	do $f1(); do $f2(); 
    }

That works just fine.  So then I did this:

    @a = (3, 5, 12, 3,  9, 23, 93, 1, 445, 33, 12);

    $sortsub = &makefun('$a <=> $b');
    @a = sort $sortsub @a;
    print join(", ", @a), "\n";

And again it worked just fine.  However, I could NOT do this:

    @a = sort &makefun('$a <=> $b') @a;

Which is too bad.  Of course, I would still like things like

    @a = sort { $a <=> $b; } @a;
    @a = sort { $x{$a} cmp $x{$b}; } keys %x;

to work.  You run the risk -- if you want to call it that -- that people 
would start writing stuff like this:

    @a = sort {
		# lots of code
		# might intervene here, taking
		# a long time to find the list
	  } @b;

But I still like the idea.  I don't see how it could break any scripts.

--tom