Fix taller tail

Author: savalet

src/df_tail.c

@@ -16,13 +16,13 @@ dataframe_t *df_tail(dataframe_t *df, int nb_rows)
     dataframe_t *new_df;
     void ***copy_src_data = df->data;
 
-    if (!nb_rows || nb_rows > df->nb_rows)
+    if (!nb_rows)
         return NULL;
     new_df = malloc(sizeof(dataframe_t));
     if (new_df == NULL)
         return NULL;
     new_df->nb_columns = df->nb_columns;
-    df->data += (df->nb_rows - nb_rows);
+    df->data += df->nb_rows - nb_rows > 0 ? df->nb_rows - nb_rows : 0;
     if (!copy_columns_type(new_df, df) ||
         !copy_columns_name(new_df, df) ||
         !copy_data(new_df, df, nb_rows))

tests/main.c

@@ -42,23 +42,25 @@ void print_df(int rows, int col, void ***data, column_type_t type)
 int main(int ac, char **av)
 {
     dataframe_t *src = df_read_csv(av[1], ";");
-    dataframe_t *df = df_sort(src, "age", sort_func);
+    dataframe_t *df = df_tail(src, 100);
 
+    df_write_csv(df, "result.csv");
     if (df == NULL)
         return 84;
-    U_DEBUG("nb_columns= %d\n", df->nb_columns);
-    U_DEBUG("nb_rows= %d\n", df->nb_rows);
-    U_DEBUG_MSG("columns: ");
+    printf("nb_columns= %d\n", df->nb_columns);
+    printf("nb_rows= %d\n", df->nb_rows);
+#if defined(U_DEBUG_MODE)
+    printf("columns: ");
     for (int a = 0; a < df->nb_columns; a++)
         printf("[%s] [%s]%s", df->column_names[a],
             TYPES[df->column_type[a]].name,
             a < df->nb_columns - 1 ? ", " : "\n");
+#endif
     for (int rows = 0; rows < df->nb_rows; rows++) {
         for (int columns = 0; columns < df->nb_columns; columns++)
                 print_df(rows, columns, df->data, df->column_type[columns]);
         puts("");
     }
-    df_write_csv(df, "result.csv");
     free(df);
     return 0;
 }