You'll probably have to change Perl_sv_cmp_locale to whatever the constant is for <=> though I'm sorry I can't seem to track that down at the moment. You may have to use sortsv_flags. The perlapi documentation is a little thin.

You'll probably have to change Perl_sv_cmp_locale to whatever the constant is for <=> though I'm sorry I can't seem to track that down at the moment

I can't find it either. Is there such a thing ? Or is sortsv() invariably lexical ?

I tried

Perl_sortsv_flags(aTHX_ AvARRAY(data),arrayLen+1,Perl_sv_cmp, flags);
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for differing values of 'flags', but it looked like 0 (and any even value) causes a lexical sort in ascending order, and 1 (and any odd value) causes a lexical sort in descending order. I didn't stumble across any value that forces a numeric sort.

The following produces the desired output:

use warnings;
use Inline C => Config =>
    CLEAN_AFTER_BUILD => 0,
    BUILD_NOISY => 1;

use Inline C => <<'END_OF_C_CODE';

    void test(AV* data) {

      I32 i;
      I32 arrayLen;
      float retval;
      SV** pvalue;

      arrayLen = av_len(data);

      sortsv(AvARRAY(data),arrayLen+1,Perl_sv_cmp);

      for (i = 0; i < arrayLen+1; i++) {

        pvalue = av_fetch(data,i,0); 
        printf("%s \n",SvPVX(*pvalue));
      }
    }

END_OF_C_CODE

my $ref = [ 5.0e-5,4.2e-5,4.3e-5,4.4e-5,4.4e-5,4.2e-5,4.2e-5,4.0e-5];

for(@$ref) {$_ = sprintf "%f", $_}

test($ref);
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I don't know if that's helpful in the "real world" application. All it does is stringify the values in the array reference into such a form that the lexical sort produces the desired output. There may be a better way of achieving that stringification.

Cheers,
Rob

PP_sort.c contains all these routines which appear to be defined such that they could be used as alternatives to Perl_sv_cmp:

S_sortcv(pTHX_ SV *a, SV *b)
S_sortcv_stacked(pTHX_ SV *a, SV *b)
S_sortcv_xsub(pTHX_ SV *a, SV *b)

S_sv_ncmp(pTHX_ SV *a, SV *b)
S_sv_i_ncmp(pTHX_ SV *a, SV *b)

S_amagic_ncmp(pTHX_ register SV *a, register SV *b)
S_amagic_i_ncmp(pTHX_ register SV *a, register SV *b)
S_amagic_cmp(pTHX_ register SV *str1, register SV *str2)
S_amagic_cmp_locale(pTHX_ register SV *str1, register SV *str2)
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They are prototyped in proto.h and aliased in embed.h, but even including those explicitly does not allow them to be seen at compile time?

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