Ah, but the difference between Apache 2.48 and 2.49 is unlike the difference between Perl 5 and 6. This is more like the difference between the Apache 1.3 and 2 series, because the two versions are not really compatible.

In your example, almost anything looking for Apache 2.48 would be fine if it used 2.49, so using a symlink is fine. But a program looking to be run as Perl 5 would not work if interpreted as Perl 6. Everything would be fine if we started using separate binary names, eg perl5 and perl6, but that's kind of a hassle. People would rather just be able to say #!/usr/bin/perl and have it work either way, which is the purpose of this discussion. How do we get it to work either way, reliably?

Personally I think we should give up on that idea. It seems more reasonable to me just to say that Perl 6 will be perl now (well, after it's released), and Perl 5 will be perl5. Otherwise we're condemning ourselves to always run in Perl 5 mode by default, forever more. But, on the other hand, it causes problems for those who have a big library and don't want to have to go through and change all the shebang lines to /usr/bin/perl5, but still have a Perl 6 installed without having to write /usr/bin/perl6.

It's a tough problem, but it seems like since Perl 6 is already committed to not worrying about backward compatibility, why force a default mode that we're hoping will go away eventually anyway? If we don't do it now, at what point in the future will we be able to say, "Okay, let's make Perl 6 the default, finally." I would argue that we'll never be able to do it unless it's upfront.

Alright, enough rambling. Back to your regularly scheduled forum.

In reply to Re: Re: Re: Re: Ensuring forward compatibility by kelan
in thread Ensuring forward compatibility by DrHyde

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