Re: Re^3: Why not support this syntax?

Good idea, and we can even cover that one ourselves, too:

sub is_ordered_according_to {
    my ($binary_predicate, @values) = @_;
    if (@values < 3) {
        return $binary_predicate->(@values);
    } else {
        return $binary_predicate->($values[0], $values[1])
            && is_ordered_according_to($binary_predicate, 
                                       @values[1..$#values]);
    }
}

sub less_than {
    return shift() < shift();
}

print is_ordered_according_to(\&less_than, 
1, 2, 3, 4, 5, 6) ? "yes" : "no", "\n" ;
print is_ordered_according_to(\&less_than, 
3, 2, 1, 4, 5, 6) ? "yes" : "no", "\n" ;
print is_ordered_according_to(\&less_than, 
1, 2, 3, 4, 6, 5) ? "yes" : "no", "\n" ;
[download]

Christian Lemburg
Brainbench MVP for Perl
http://www.brainbench.com

Comment on Re: Re^3: Why not support this syntax? Download Code

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Re: Re: Re^3: Why not support this syntax? by MeowChow (Vicar) on Apr 24, 2001 at 20:12 UTC
Nice, but try this: `$val = $min <= $x < $y <= $z <= $max` [download] IMO, A syntactic solution would be both cleaner and faster. MeowChow s aamecha.s a..a\u$&owag.print	[reply] [d/l]
Re: Re: Re^3: Why not support this syntax? by scott (Chaplain) on Apr 30, 2001 at 18:13 UTC
Cool. If you don't mind, I'll just add this to my personal collection of bits o'code. Good idea, and we can even cover that one ourselves, too But we can cover anything ourselves ... with enough effort. From another of your posts on the same topic: Perl is a language for getting your job done - right. After writing this little subroutine, the job is done. Why wait for other people to do jobs for you that you can do for yourself in 30 seconds. I don't think anyone said anything about waiting. Making Perl6 will require a great deal of effort, it's going to happen regardless of whether or not this particular syntax is included, and the process of deciding what the syntax will be has been deliberately opened to public debate. So why not let everyone know on what we think said effort should be spent constructing? Philosophically yours, Scott	[reply]