| data_step | SAS IF-style data step logic for data.table |
| delete_if | Create a SAS-style DELETE rule |
| else_do | Create a SAS-style ELSE rule |
| else_if_do | Create a SAS-style ELSE IF rule |
| if_do | Create a SAS-style IF rule |
| if_independent | Create an independent SAS-style IF rule |