On Tue, Aug 16, 2005 at 02:04:41PM +0100, Nicholas Clark wrote: > On Thu, Aug 11, 2005 at 01:35:14AM +0800, Autrijus Tang wrote: > > On Wed, Aug 10, 2005 at 07:32:01PM +0200, TSa wrote: > > > Counting the sigil quadriga as 4, what is the fifth element? > > & @ $ % :: > > In Perl5, :: is replaced by *. > > Strictly in Perl 5 there are 7 types > SCALAR, ARRAY, HASH, CODE, GLOB, FORMAT and IO. > > (where IO might actually be 2 types, file handles and directory handles, > and in turn FORMAT is implemented as a subtype of CODE. > > Also, internally there are 16 variants of SV*, with mostly a 1 to 1 mapping > for all the types except SCALAR, which sort of absorbs the other 10. Except > that the null SV type is easily directly morphable into any of the others.
It would be great if we can use a type-directed transform from Perl 5
syntax tree into PIL/Perl6, i.e. annotate each term with the 16
variants, maybe with union/intersection types that represents ambiguous
context, such as:
f(reverse(g()));
Hm, I seem to remember that Gary Jackson (cc'ed) is working on that,
as his Summer of Code project. Gary, can you share with us how you
plan to approach that, and/or how to get involved to your project?
Thanks,
/Autrijus/
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