Simon Cozens:
# I've hit upon quite a major problem with implementing
# Perl scalar PMCs. The problem is that the code is just
# too damned ugly for words.
#
# Remember that PMCs have a data area which is a void
# pointer; I'm connecting that to a structure which has
# integer, number and string slots. Those of you familiar
# with Perl SVs will know exactly where I'm coming from.
#
# So, for instance, the method to get an integer value
# ends up looking like this:
#
# static INTVAL Parrot_scalar_get_integer (struct Parrot_Interp
# *interpreter, PMC* pmc) {
# if (pmc->flags & PS_INTEGER_OK) {
# return ((struct PerlScalarData *)(pmc->data))->intdata;
# } else if (pmc->flags & PS_NUMBER_OK) {
# pmc->flags |= PS_INTEGER_OK;
# return ((struct PerlScalarData*)(pmc->data))->intdata
# = (INTVAL)(((struct PerlScalarData*)(pmc->data))->numdata);
# ...
# }
static INTVAL
Parrot_scalar_get_integer(struct Parrot_Interp *interpreter, PMC* pmc) {
PSD* sd=(PSD*)pmc->data;
if(FLAG_pmc_iok_TEST(pmc)) {
return sd->intdata;
}
else if(FLAG_pmc_nok_TEST(pmc)) {
return sd->intdata=(INTVAL)sd->numdata; /*should this be floatdata?*/
}
else if(FLAG_pmc_sok_TEST(pmc)) {
return sd->intdata=Parrot_string_to_int(psd->strdata);
}
else if(FLAG_pmc_rok_TEST(pmc)) {
/* reference */
return (*sd->refdata->vtable[get_integer])(interpreter, sd->refdata);
/*or however vtable funcs are called*/
}
else {
/*this should never happen*/
Parrot_croak("PANIC: Parrot_scalar_get_integer");
return 0; /*keep compilers happy*/
}
}
IIRC, that even complies with coding standards.
Beyond that there's the distinct possibility of vtable swap outs, but it
seems a bit extreme to swap out the vtable when you execute $foo+1.
# And that's mild. I could typedef "struct PerlScalarData" to "PSD",
# but that wouldn't really help that much. And I could fudge it all
# with macros, but that's a Perl 5 thing to do.
Macros for setting and testing flags are good. Other macros are bad.
(Although I've been seriously thinking about how annoying it is to type
'struct Parrot_Interp *interpreter' all the time...)
# Any suggestions for cleaning up this crap and making it a bit
# more maintainable?
As Andy already said, temporaries.
--Brent Dax
[EMAIL PROTECTED]
Configure pumpking for Perl 6
When I take action, I'm not going to fire a $2 million missile at a $10
empty tent and hit a camel in the butt.
--Dubya
