Index - O
| Ok | Navi.Data.Result |
| onErr | Navi.Data.Result |
| onOk | Navi.Data.Result |
| onResult | Navi.Data.Result |
| openBinaryFile | Navi.Prelude |
| Ord | Navi.Prelude |
| osp | Navi.Prelude |
| OsPath | Navi.Prelude |
| ospPathSep | Navi.Prelude |
| otherwise | Navi.Prelude |
| output | Navi.Data.CommandResult |
| over' | Navi.Prelude |