Note: this is my understanding of the situation; I could be wrong.
Sam Tregar:
# On Sun, 2 Sep 2001, Simon Cozens wrote:
#
# > For instance, the Parrot VM will have a register
# architecture, rather
# > than a stack architecture.
#
# s/rather than/as well as/; # we've got a stack of register
# frames, right?
IIRC, that's mostly for when we run out of registers or we're changing
scopes or whatever. For the most part, it's a register architecture.
# > There will be global and private opcode tables; that is to
# say, an area
# > of the bytecode can define a set of custom operations that
# it will use.
# > These areas will roughly map to compilation units of the original
# > source; each precompiled module will have its own opcode table.
#
# Side note: this isn't making sense to me. I'm looking
# forward to further
# explanation!
In other words, when you have sub foo {} in your code, it will be
assigned an opcode number in the 'private' section. The global section
is for things that are built-in to Parrot, while the private section is
for stuff you write. (Right?)
# > If our PMC is a string and has a vtable which implements Perl-like
# > string operations, this will return the length of the
# string. If, on the
# > other hand, the PMC is an array, we might get back the number of
# > elements in the array. (If that's what we want it to do.)
#
# Ok, so one example of a PMC is a Perl string...
>From what I've seen, PMCs will represent SVs, AVs, and HVs at the opcode
level. (When you get down to C, it's really SVs and AVs and HVs, but in
bytecode it's all PMCs.)
# > Parrot provides a programmer-friendly view of strings. The
# Parrot string
# > handling subsection handles all the work of memory allocation,
# > expansion, and so on behind the scenes. It also deals with
# some of the
# > encoding headaches that can plague Unicode-aware languages.
#
# Or not! Are Perl strings PMCs or not? Why does Parrot want to handle
# Unicode? Shouldn't that go in a specific language's string
# PMC vtables?
Perl *scalars* are PMCs. Those PMCs may hold strings within them.
However, string manipulation is done in special string registers, which
are *not* PMCs.
--Brent Dax
[EMAIL PROTECTED]
"...and if the answers are inadequate, the pumpqueen will be overthrown
in a bloody coup by programmers flinging dead Java programs over the
walls with a trebuchet."
