At 10:52 AM 10/1/2001 -0400, Gregor N. Purdy wrote:
>Dan --
>
> > Here's a list of manifest constants I think Parrot should know about.
> > Anyone care to add to the list?
> >
> > '' (empty string)
> > 0
> > 1
> > undef
> > NaN
> > pi
> > e
> > epsilon (maybe)
>
>That brings up an interesting issue. The Ix registers initialize to
>zero, as do the Nx registers. These are valid values for those
>register types. However, the Sx registers initialize to NULL, which is
>not treated elsewhere (such as print_sc) as a valid string value.
The registers shouldn't be assumed to initialize to anything. (I'll start
stuffing 0xDEADBEEF in there if I have to... :) Only the PMC registers
should go to a value, and that's only because it'll cause the GC fits if
they don't.
>Now, I'm not sure what you mean when you say "Parrot should know
>about" these. Are you referring to special treatment in the
>assembler? Are you suggesting every const_table be initialized with
>these values?
Basically these are constants that are known and provided to you by the
interpreter. (So we can avoid people hand-rolling pi and e, amongst other
things)
I think we might end up with a get_manifest_constant opcode that takes a
register and a known named constant, like so:
get_manifest_constant N3, pi
and looks up the constant from the table we build into parrot. Might want
to hide that so that:
set N3, pi
automagically does the conversion.
Dan
--------------------------------------"it's like this"-------------------
Dan Sugalski even samurai
[EMAIL PROTECTED] have teddy bears and even
teddy bears get drunk
