Index - O
| odd | Nix.Prelude |
| on | Nix.Prelude |
| OnDecodeError | Nix.Prelude |
| One | Nix.Prelude |
| one | Nix.Prelude |
| OneItem | Nix.Prelude, Nix.Prelude |
| OnError | Nix.Prelude |
| Op | |
| 1 (Data Constructor) | Nix.Prelude |
| 2 (Type/Class) | Nix.Prelude |
| opaqueVal | Nix.Normal, Nix |
| OperatorInfo | |
| 1 (Type/Class) | Nix.Parser, Nix |
| 2 (Data Constructor) | Nix.Parser, Nix |
| operatorName | Nix.Parser, Nix |
| Option | |
| 1 (Data Constructor) | Nix.Prelude |
| 2 (Type/Class) | Nix.Prelude |
| optional | Nix.Prelude |
| Options | |
| 1 (Type/Class) | Nix.Options, Nix |
| 2 (Data Constructor) | Nix.Options, Nix |
| or | Nix.Prelude |
| Ord | Nix.Prelude |
| ord | Nix.Prelude |
| Ordering | Nix.Prelude |
| ordNub | Nix.Prelude |
| ordNubOn | Nix.Prelude |
| orM | Nix.Prelude |
| otherwise | Nix.Prelude |
| over | Nix.Utils, Nix.Prelude |