On Fri, Jan 20, 2006 at 04:20:54PM -0500, Rob Kinyon wrote:
> Pros: Larry doesn't have to do anything more on the WMoT.
> Cons: The community, for some reason, really wants this
> auto-translator, even though there wasn't one for P4->P5 and P5->P6 is
> a greater leap than P4->P5 was.
But (as I understood it) the P4->P5 leap was not intended to be so great
that a translator would be needed. In fact, that confuses cause and effect.
Because the technology wasn't there to write a translator, it constrained the
size of the leap. The important part was that for Perl 5 to still be Perl,
it had to keep running the vast majority of Perl scripts.
In fact, Perl 5 still strives to maintain Perl 1 compatibility (and the
perl5-porters joke is that even thinking about breaking this is the fastest
way to summon the thought, er backwards compatibility police with a script
he's been running unchanged since 1987). Why else can you still:
$ perl -le '$h{1} = "Perl"; print values h'
Perl
$ perl -le 'push a, "Perl"; print @a'
Perl
I believe that the translator is seen as needed (even by @Larry, I think)
to maintain the same level of continuity in the Perl 5->6 transition as
Perl 4->5 - your existing monolithic script runs on the newer Perl
interpreter, and you can edit (within that same file) as and when you need
to.
Otherwise you're in the situation where you can only inter-operate languages
the whole file level. Which means that it's the same actions to migrate from
Perl 5 to (say) Python as from Perl 5 to Perl 6. And somehow I think that
$Larry has some bias about which language he'd prefer everyone to find it
easiest to migrate to, even if he's too modest to admit it.
Nicholas Clark
