Index - U
| uncurry | Prolude.Core, Prolude |
| undefined | Prolude.Core, Prolude |
| uninterruptibleMask | Prolude.Exception, Prolude |
| uninterruptibleMask_ | Prolude.Exception, Prolude |
| unless | Prolude.Monad, Prolude |
| unlines | Prolude.Core, Prolude |
| unsafeEvaluate | Prolude.Exception, Prolude |
| unsafeThrow | Prolude.Exception, Prolude |
| unwords | Prolude.Core, Prolude |
| unzip | Prolude.Core, Prolude |
| UpdateOption | Prolude.MongoDB, Prolude |
| userError | Prolude.Core, Prolude |
| UserInterrupt | Prolude.Exception, Prolude |
| utctDay | Prolude.Time, Prolude |
| utctDayTime | Prolude.Time, Prolude |
| UTCTime | |
| 1 (Type/Class) | Prolude.Time, Prolude |
| 2 (Data Constructor) | Prolude.Time, Prolude |
| utcTimeToPOSIXSeconds | Prolude.Time, Prolude |