Index - D
| dateFmt | Locale | 
| dateTimeFmt | Locale | 
| Day | Time | 
| December | Time | 
| decodeFloat | Prelude | 
| defaultTimeLocale | Locale | 
| delete | List | 
| deleteBy | List | 
| deleteFirstsBy | List | 
| denominator | Ratio | 
| deRefStablePtr | StablePtr | 
| diffClockTimes | Time | 
| digitToInt | Char | 
| div | Prelude | 
| divMod | Prelude | 
| doesDirectoryExist | Directory | 
| doesFileExist | Directory | 
| doesNotExistErrorType | MarshalError | 
| Double | Prelude | 
| drop | Prelude, List | 
| dropWhile | Prelude, List |