Sorry if I missed the correspondence between Perl6::Declare and Devel::Declare & Perl6::Signatures. If indeed there is any?

Perl6::Declare lets you declare subroutine/methods using Perl 6 signatures, which are lovely. I heard this turns out to actually be faster than Perl 5 calling conventions,

Devel::Declare talks about "declarator magic" and Perl6::Signature contains a Parse::RecDescent-based parser for signatures.".

If anything that uses P::RD turns out to be faster than my( $x, $y, $z ) = @_;, it will indeed be "magic". Oh! and I'll eat my hat! (I'll have to buy a hat to eat, but I'm sure I can find something tasty at a thrift shop:)

To clarify, what I meant by my request for less overhead, was a reduction in the internal (C-level) overhead associated with calling a perl subroutine, that results in this kind of comparison of similar subroutines coded in Perl and another bytecode compiled, interpreted language: Java.

Are Perl's function calls slow?

The archetypal test of function call performance is the Ackermann Function. Go here to see the list of other languages that out-perform Perl for function call performance. Many of those are fully pre-compiled languages. Many are not.

For comparison purposes, look at straight forward implementations in Perl, with the same in Java.

Perl:

        
    P:\test\MJD>ack1 9
    Ack(3,9): 4093
    78.843 83.671 0 0
[download]

Java:

P:\test\MJD>timethis "c:javac ackermann.java && java ackermann 9"

TimeThis :  Command Line :  c:javac ackermann.java && java ackermann 9
TimeThis :    Start Time :  Fri Sep 02 22:01:28 2005

Ack(3,9): 4093

TimeThis :  Command Line :  c:javac ackermann.java && java ackermann 9
TimeThis :    Start Time :  Fri Sep 02 22:01:28 2005
TimeThis :      End Time :  Fri Sep 02 22:01:29 2005
TimeThis :  Elapsed Time :  00:00:01.031
[download]

I've included the compilation and runtime for Java to even the score a little. JIT was not enabled.

So 83.6 seconds for Perl, and 1.031 seconds for Java!

Conclusion: Perl's function calls are slow.