Re: How to call Encode::decode from Perl XS

Bases on my experience, it could be something like (untested)

int encode_loaded = 0;
SV *m_encode = newSVpvs ("decode"); /* Or "Encode::decode", I'm not su
+re */
SV *sv_enc   = newSVpvs ("cp1252");

my_foo (char *buffer)
{
    int result;

    if (!encode_loaded) {
        ENTER;
        load_module (PERL_LOADMOD_NOIMPORT, newSVpvs ("Encode"), NULL,
+ NULL, NULL);
        LEAVE;
        encode_loaded = 1;
        }

    PUSHMARK (sp);
    EXTEND (sp, 2);
    PUSHs (sv_enc);
    PUSHs (newSVpv (buffer));
    PUTBACK;
    result = call_sv (m_encode, G_SCALAR | G_METHOD);
    SPAGAIN;
    if (result) {
        SV *encoded = POPs;
        /* Do more */
        }
    PUTBACK;
    }
[download]

And some mortalization might be needed to not leak.

Enjoy, Have FUN! H.Merijn

Comment on Re: How to call Encode::decode from Perl XS Select or Download Code

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Re^2: How to call Encode::decode from Perl XS by Anonymous Monk on May 09, 2011 at 14:24 UTC
all that load checking goes in the .pm file in the form of "use Encode...", kiss :)	[reply]
Re^3: How to call Encode::decode from Perl XS by Tux (Canon) on May 09, 2011 at 15:17 UTC
Yes and no. If you want a module to automatically load another module from XS, and not import all functions/methods, this is a cleaner way to do so. Of course you can croak/fail/die/barf/puke when a user tries to invoke something that he/she did not explicitely load, but as Encode is a CORE module I see no harm in hiding the require from XS and making the underlying module DWIM more. I agree that this is a grey/gray area and opinions may well differ if which case I think you should agree to disagree. XS is a different world and pulling the right strings is sometimes extremely hard compared to how easy perl made it in the language level itself. Enjoy, Have FUN! H.Merijn	[reply]
Re^4: How to call Encode::decode from Perl XS by ikegami (Patriarch) on May 09, 2011 at 15:43 UTC
If you want a module to automatically load another module from XS, and not import all functions/methods, Not importing can be done from Perl too. It's not an advantage of XS. In Perl, not importing is done by using `use Exporter qw( );` [download] or `require Exporter;` [download] instead of `use Exporter;` [download] As for ~~automatically~~dynamically loading a module, a need hasn't been mentioned. Update: Added first two sentences to clear up confusion mentioned in private message.	[reply] [d/l] [select]
Re^5: How to call Encode::decode from Perl XS by mje (Curate) on May 09, 2011 at 16:22 UTC
Re^6: How to call Encode::decode from Perl XS by ikegami (Patriarch) on May 09, 2011 at 16:29 UTC
Re^2: How to call Encode::decode from Perl XS by mje (Curate) on May 09, 2011 at 14:40 UTC
Thanks Merijn, I'll look into this.	[reply]