Index - O
| offsetTime | System.Time.Extra, Extra |
| offsetTimeIncrease | System.Time.Extra, Extra |
| once | Control.Concurrent.Extra, Extra |
| onceFork | Control.Concurrent.Extra, Extra |
| onException | Control.Exception.Extra |
| openBinaryFile | System.IO.Extra |
| openBinaryTempFile | System.IO.Extra |
| openBinaryTempFileWithDefaultPermissions | System.IO.Extra |
| openFile | System.IO.Extra |
| openTempFile | System.IO.Extra |
| openTempFileWithDefaultPermissions | System.IO.Extra |
| or | Data.List.Extra |
| orM | Control.Monad.Extra, Extra |
| os | System.Info.Extra |
| outputNL | System.IO.Extra |
| Overflow | Control.Exception.Extra |