implementation of DataFrame::nrows that does not have to pay the price of R wanting to be too smart. #124

romainfrancois · romainfrancois · commit eaded60ef1b7 · 2014-04-01T17:17:29.000+02:00
diff --git a/inst/include/Rcpp/DataFrame.h b/inst/include/Rcpp/DataFrame.h
@@ -20,9 +20,16 @@ namespace Rcpp{
         ~DataFrame_Impl() ;
 
         int nrows() const {
-            SEXP rn = Rf_getAttrib( *this, R_RowNamesSymbol ) ;
-            if( TYPEOF(rn) == INTSXP && LENGTH(rn) == 2 && INTEGER(rn)[0] == NA_INTEGER ) return INTEGER(rn)[1] ;
+            SEXP rn = R_NilValue ; 
+            SEXP att = ATTRIB( Storage::get__() ); 
+            while( att != R_NilValue ){
+                if( TAG(att) == R_RowNamesSymbol ){
+                    rn = CAR(att) ;        
+                }
+                att = CDR(att) ;    
+            }
             if( Rf_isNull(rn) ) return 0 ;
+            if( TYPEOF(rn) == INTSXP && LENGTH(rn) == 2 && INTEGER(rn)[0] == NA_INTEGER ) return -INTEGER(rn)[1] ;
             return LENGTH(rn) ;
         }
         
