Index - O
| onCompilationError | Hint.Internal |
| Option | Language.Haskell.Interpreter |
| OptionVal | Language.Haskell.Interpreter |
| OverlappingInstances | Language.Haskell.Interpreter, Language.Haskell.Interpreter.Extension |
| OverloadedLabels | Language.Haskell.Interpreter, Language.Haskell.Interpreter.Extension |
| OverloadedLists | Language.Haskell.Interpreter, Language.Haskell.Interpreter.Extension |
| OverloadedStrings | Language.Haskell.Interpreter, Language.Haskell.Interpreter.Extension |