in reply to Why do we need $a and $b to be special?

IIRC, the original reason for $a and $b is that they were much faster then using @_. That's less true then it used to be, but it's still the case that most sort routines are trivial enough that writing $_[0] and $_[1] instead of $a and $b makes them significantly more complex-looking.

In any case, as you say, they'll be gone in perl6. They aren't going away in perl5, because it'd instantly break everybody's code.

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Re^2: Why do we need $a and $b to be special?
by ambrus (Abbot) on Jul 30, 2004 at 12:26 UTC
    IIRC, the original reason for $a and $b is that they were much faster then using @_.

    I thought the original reason was that sort with a block was in perl4 and there were no subroutines at that time, but I might be wrong.

[reply]

      Even Perl 1 had subroutines. I don't have time to look at how sort worked then, but I do remember having to say somethign like do &subname to make subroutine calls in Perl 1.

      Of course, now that I post, I immediately realize you probably meant didn't have lexicals, which is true.

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