Re^4: Using vec() from XS

1. synthesize an OP o

That phrase means absolutely nothing to me! So I perldoc'd; I grepped the sources; I filtered the htmlise perldocs; I googled.

Only the latter turned up that phrase. And other than your post above, the only references google has to "synthesizing an[d] op", from the >25 billion web pages it indexes, are:

synthesize an op-. erating procedure
synthesize an o p. tima. supervim
synthesize an op-. timal topology
synthesize an op-. tical matched spatial filter
(synthesize) an op-. erationally larger antenna

So, could you please explain what you mean by that?

I did look at Perl_fold_constants:

OP *
Perl_fold_constants(pTHX_ register OP *o)
{
    register OP *curop;
    I32 type = o->op_type;
    SV *sv;

    if (PL_opargs[type] & OA_RETSCALAR)
    scalar(o);
    if (PL_opargs[type] & OA_TARGET && !o->op_targ)
    o->op_targ = pad_alloc(type, SVs_PADTMP);

    /* integerize op, unless it happens to be C<-foo>.
     * XXX should pp_i_negate() do magic string negation instead? */
    if ((PL_opargs[type] & OA_OTHERINT) && (PL_hints & HINT_INTEGER)
    && !(type == OP_NEGATE && cUNOPo->op_first->op_type == OP_CONST
         && (cUNOPo->op_first->op_private & OPpCONST_BARE)))
    {
    o->op_ppaddr = PL_ppaddr[type = ++(o->op_type)];
    }

    if (!(PL_opargs[type] & OA_FOLDCONST))
    goto nope;

    switch (type) {
    case OP_NEGATE:
    /* XXX might want a ck_negate() for this */
    cUNOPo->op_first->op_private &= ~OPpCONST_STRICT;
    break;
    case OP_UCFIRST:
    case OP_LCFIRST:
    case OP_UC:
    case OP_LC:
    case OP_SLT:
    case OP_SGT:
    case OP_SLE:
    case OP_SGE:
    case OP_SCMP:
    /* XXX what about the numeric ops? */
    if (PL_hints & HINT_LOCALE)
        goto nope;
    }

    if (PL_error_count)
    goto nope;        /* Don't try to run w/ errors */

    for (curop = LINKLIST(o); curop != o; curop = LINKLIST(curop)) {
    if ((curop->op_type != OP_CONST ||
         (curop->op_private & OPpCONST_BARE)) &&
        curop->op_type != OP_LIST &&
        curop->op_type != OP_SCALAR &&
        curop->op_type != OP_NULL &&
        curop->op_type != OP_PUSHMARK)
    {
        goto nope;
    }
    }

    curop = LINKLIST(o);
    o->op_next = 0;
    PL_op = curop;
    CALLRUNOPS(aTHX);
    sv = *(PL_stack_sp--);
    if (o->op_targ && sv == PAD_SV(o->op_targ))    /* grab pad temp? *
+/
    pad_swipe(o->op_targ,  FALSE);
    else if (SvTEMP(sv)) {            /* grab mortal temp? */
    (void)SvREFCNT_inc(sv);
    SvTEMP_off(sv);
    }
    op_free(o);
    if (type == OP_RV2GV)
    return newGVOP(OP_GV, 0, (GV*)sv);
    return newSVOP(OP_CONST, 0, sv);

  nope:
    return o;
}
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and I can relate nothing there to that phrase. So, could you please treat me like the thicko I am, and explain what ... you are suggesting, cos I just do not ... understand!

A long time ago, before the dawn of time, a young, budding mechanical engineer was taken to task for a suggestion he made, but failed to be able to explain. The upshot was: If you cannot explain it, you do not really understand it, so you should not suggest it.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

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Re^5: Using vec() from XS by salva (Canon) on Sep 24, 2008 at 07:48 UTC
The problem is me, probably, English is not my native tongue! An OP is the structure used internally by perl to represent program code. By synthesize an OP I meant to artificially build and OP (in opposition to its natural birth at the perl parser). And that means creating some OPs (maybe just one will do, I am not sure) using the `newXXXOP` functions, building a tree/sequence with them and setting up its internal state as if they had come from the parser. But anyway, all this stuff would be far more complicated than just replicating the code for `pp_vec`.	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re^5: Using vec() from XS
by salva (Canon) on Sep 24, 2008 at 07:48 UTC

An OP is the structure used internally by perl to represent program code. By synthesize an OP I meant to artificially build and OP (in opposition to its natural birth at the perl parser).

And that means creating some OPs (maybe just one will do, I am not sure) using the newXXXOP functions, building a tree/sequence with them and setting up its internal state as if they had come from the parser.

But anyway, all this stuff would be far more complicated than just replicating the code for pp_vec.

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