CharacterVectorOrderer::CharacterVectorOrderer(const CharacterVector& data) :
orders(no_init(data.size()))
{
int n = data.size();
if (n == 0) return;
dplyr_hash_set<SEXP> set(n);
// 1 - gather unique SEXP pointers from data
SEXP* p_data = Rcpp::internal::r_vector_start<STRSXP>(data);
SEXP previous = *p_data++;
set.insert(previous);
for (int i = 1; i < n; i++, p_data++) {
SEXP s = *p_data;
// we've just seen this string, keep going
if (s == previous) continue;
// is this string in the set already
set.insert(s);
previous = s;
}
// retrieve unique strings from the set
int n_uniques = set.size();
LOG_VERBOSE << "Sorting " << n_uniques << " unique character elements";
CharacterVector uniques(set.begin(), set.end());
static Function sort("sort", R_BaseEnv);
CharacterVector s_uniques = Language(sort, uniques).fast_eval();
// order the uniques with a callback to R
IntegerVector o = r_match(uniques, s_uniques);
// combine uniques and o into a hash map for fast retrieval
dplyr_hash_map<SEXP, int> map(n_uniques);
for (int i = 0; i < n_uniques; i++) {
map.insert(std::make_pair(uniques[i], o[i]));
}
// grab min ranks
p_data = Rcpp::internal::r_vector_start<STRSXP>(data);
previous = *p_data++;
int o_pos;
orders[0] = o_pos = map.find(previous)->second;
for (int i = 1; i < n; ++i, ++p_data) {
SEXP s = *p_data;
if (s == previous) {
orders[i] = o_pos;
continue;
}
previous = s;
orders[i] = o_pos = map.find(s)->second;
}
}
CharacterVectorOrderer::CharacterVectorOrderer( const CharacterVector& data_ ) :
data(data_),
set(),
orders(no_init(data.size()))
{
int n = data.size() ;
if( n == 0 ) return ;
// 1 - gather unique SEXP pointers from data
SEXP* p_data = Rcpp::internal::r_vector_start<STRSXP>(data);
SEXP previous = *p_data++ ;
set.insert( previous ) ;
for( int i=1; i<n; i++, p_data++){
SEXP s = *p_data ;
// we've just seen this string, keep going
if( s == previous ) continue ;
// is this string in the set already
set.insert(s) ;
previous = s ;
}
// retrieve unique strings from the set
int n_uniques = set.size() ;
CharacterVector uniques( set.begin(), set.end() ) ;
// order the uniques with a callback to R
IntegerVector o = Language( "rank", uniques, _["ties.method"] = "min", _["na.last"] = "keep" ).fast_eval() ;
// combine uniques and o into a hash map for fast retrieval
dplyr_hash_map<SEXP,int> map ;
for( int i=0; i<n_uniques; i++){
map.insert( std::make_pair(uniques[i], o[i] ) ) ;
}
// grab min ranks
p_data = Rcpp::internal::r_vector_start<STRSXP>(data);
previous = *p_data++ ;
int o_pos ;
orders[0] = o_pos = map.find(previous)->second ;
for( int i=1; i<n; i++, p_data++){
SEXP s = *p_data;
if( s == previous ) {
orders[i] = o_pos ;
continue ;
}
previous = s ;
orders[i] = o_pos = map.find(previous)->second ;
}
}
