Re: sub and anonymous sub

[rinceWind]

Interestingly, I thinkl there is a cleaner way to do it. My experience of other programming languages is showing. The algorithm you have given is non-reentrant, hence non-threadsafe.

Instead, I prefer passing in a level number to recurse, which means that separate threads calling recurse will not interfere with one another.

#(1)
    sub recurse { #(2)
        my ($depth) = @_;
        print +("   .") x $depth . "current depth:$depth\n" ;
        recurse($depth + 1) if $depth < 3;
        print +("   .") x $depth . "current depth:$depth\n" ;
    } #(3)
#(4)

recurse(0); # (5)

I know perl is not thread safe, but perl 6 and/or perl 5.x might be.

My $0.02 --rW

Update: Gerbil is right. I don't need the extra braces. This is what comes with cutting and pasting someone else's example rather than rewriting from scratch.

Have edited the example to take on Gerbil's suggestions

[Gerbil]

I am far away from being a mighty Perl hacker, but I've done recursion depth counting this way all the time. It's "cleaner" because you don't have to understand Perl-specific techniques. And it's thread-safe, too? Cool ;) Didn't know that... But why keep the curly brackets?

sub recurse {
    my ($depth) = @_;
    print +("   .") x $depth . "current depth:$depth\n" ;
    recurse($depth + 1) if $depth < 3;
    print +("   .") x $depth . "current depth:$depth\n" ;
}

recurse(-1);

This is the same, right? Additionally, I would start with recurse(0);