in reply to
Re^3: Perl 5 Optimizing Compiler, Part 5: A Vague Outline Emerges
in thread Perl 5 Optimizing Compiler, Part 5: A Vague Outline Emerges
... a fast subset of perl...
The same thing came up in Perl 6 development more times than I could remember. Someone would show up and say "I have a very basic Perl 6 implementation on $virtual_machine that's n times faster than $other_implementation!" and it turns out they had implemented a calculator which did integer math.
No disrespect to Flavio or Perlito, but "fast subset" only starts to get interesting when that "subset" is more set than sub.