| O | GHC.Base |
| objectName | GHC.ExecutionStack.Internal, GHC.ExecutionStack |
| odd | GHC.Real, Prelude |
| oldGenFactor | GHC.RTS.Flags |
| on | Data.Function |
| OneLineGCStats | GHC.RTS.Flags |
| OneShot | GHC.Event |
| oneShot | GHC.Base, GHC.Exts |
| onException | |
| 1 (Function) | GHC.IO |
| 2 (Function) | Control.Exception.Base, Control.Exception |
| Op | |
| 1 (Type/Class) | Data.Functor.Contravariant |
| 2 (Data Constructor) | Data.Functor.Contravariant |
| Opaque | GHC.Base |
| openBinaryFile | GHC.IO.Handle.FD, System.IO |
| openBinaryTempFile | System.IO |
| openBinaryTempFileWithDefaultPermissions | System.IO |
| openFile | |
| 1 (Function) | GHC.IO.FD |
| 2 (Function) | GHC.IO.Handle.FD, System.IO |
| openFileBlocking | GHC.IO.Handle.FD |
| OpenPunctuation | GHC.Unicode, Data.Char |
| openTempFile | System.IO |
| openTempFileWithDefaultPermissions | System.IO |
| openTextEncoding | GHC.IO.Handle.Internals |
| OptArg | System.Console.GetOpt |
| OptDescr | System.Console.GetOpt |
| Option | |
| 1 (Data Constructor) | System.Console.GetOpt |
| 2 (Type/Class) | Data.Semigroup |
| 3 (Data Constructor) | Data.Semigroup |
| option | |
| 1 (Function) | Text.ParserCombinators.ReadP |
| 2 (Function) | Data.Semigroup |
| optional | |
| 1 (Function) | Text.ParserCombinators.ReadP |
| 2 (Function) | Control.Applicative |
| or | |
| 1 (Function) | GHC.List, GHC.OldList |
| 2 (Function) | Data.Foldable, Data.List, Prelude |
| or# | GHC.Base, GHC.Exts |
| Ord | GHC.Base, Data.Ord, Prelude |
| ord | GHC.Base, Data.Char |
| ord# | GHC.Base, GHC.Exts |
| Ord1 | Data.Functor.Classes |
| Ord2 | Data.Functor.Classes |
| Ordering | GHC.Base, Data.Ord, Prelude |
| orElse | GHC.Conc.Sync, GHC.Conc |
| orI# | GHC.Base, GHC.Exts |
| orInteger | GHC.Num |
| orNatural | GHC.Natural, GHC.Num |
| os | System.Info |
| OtherError | GHC.IO.Exception |
| OtherLetter | GHC.Unicode, Data.Char |
| OtherNumber | GHC.Unicode, Data.Char |
| OtherPunctuation | GHC.Unicode, Data.Char |
| OtherSymbol | GHC.Unicode, Data.Char |
| otherwise | GHC.Base, Data.Bool, Prelude |
| outer | Data.Type.Equality |
| outputNL | GHC.IO.Handle.Types, GHC.IO.Handle, System.IO |
| OutputUnderflow | GHC.IO.Encoding.Types, GHC.IO.Encoding |
| Overflow | GHC.Exception.Type, GHC.Exception, Control.Exception.Base, Control.Exception |
| overflowError | GHC.Real |
| overflowException | GHC.Exception.Type, GHC.Exception |
| o_APPEND | System.Posix.Internals |
| o_BINARY | System.Posix.Internals |
| o_CREAT | System.Posix.Internals |
| o_EXCL | System.Posix.Internals |
| o_NOCTTY | System.Posix.Internals |
| o_NONBLOCK | System.Posix.Internals |
| o_RDONLY | System.Posix.Internals |
| o_RDWR | System.Posix.Internals |
| o_TRUNC | System.Posix.Internals |
| o_WRONLY | System.Posix.Internals |