array slices

[Xavier Noria]

I founded nothing about slices in perlguts, perlxs*, or perlapi  
(where are they documented?), so I wrote this little utility to take  
a slice from AV* data using the indices in AV* indices (integers),  
and put the result in AV* out (indices and out are guaranteed to have  
the same length):

void __slice(AV* indices, AV* data, AV* out) {
     int i;
     I32 last_index;
     I32 index;
     SV* val;
     last_index = av_len(indices);
     for (i = 0; i <= last_index; ++i) {
          index = SvIVX(*av_fetch(indices, i, 0));
          val = *av_fetch(data, index, 0);
          av_store(out, i, newSVsv(val));
     }
}

I am just starting to play around with the C API. Is this code right  
as far as XS is concerned? Is there a better idiom?

-- fxn