Index - O
| odd | AwesomePrelude |
| on | AwesomePrelude |
| onException | AwesomePrelude |
| OpenPunctuation | AwesomePrelude |
| optional | AwesomePrelude |
| or | AwesomePrelude |
| Ord | AwesomePrelude |
| ord | AwesomePrelude |
| Ordering | AwesomePrelude |
| orElse | AwesomePrelude |
| OtherError | AwesomePrelude |
| OtherLetter | AwesomePrelude |
| OtherNumber | AwesomePrelude |
| OtherPunctuation | AwesomePrelude |
| OtherSymbol | AwesomePrelude |
| otherwise | AwesomePrelude |
| Overflow | AwesomePrelude |