| Jam | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| January | Data.Time.Calendar.MonthDay, Data.Time.Calendar.Julian, Data.Time.Calendar, Data.Time | 
| JasPer_2_0 | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| JavaScript |  | 
| 1 (Data Constructor) | Distribution.System | 
| 2 (Data Constructor) | Language.Haskell.TH.Syntax, Language.Haskell.TH | 
| javaScript | Language.Haskell.TH.Lib.Internal, Language.Haskell.TH.Lib, Language.Haskell.TH | 
| JavaScriptFFI |  | 
| 1 (Data Constructor) | Language.Haskell.Extension, Distribution.Simple | 
| 2 (Data Constructor) | GHC.LanguageExtensions, GHC.LanguageExtensions.Type, Language.Haskell.TH.LanguageExtensions, Language.Haskell.TH.Syntax, Language.Haskell.TH | 
| javaStyle | Text.Parsec.Language, Text.ParserCombinators.Parsec.Language | 
| JHC | Distribution.Compiler, Distribution.Simple.Compiler, Distribution.Simple | 
| jhcProgram | Distribution.Simple.Program.Builtin, Distribution.Simple.Program | 
| Jn# | GHC.Integer.GMP.Internals | 
| join | Distribution.Compat.Prelude, Distribution.Compat.Prelude.Internal, Control.Monad.Identity, Control.Monad.State.Strict, Control.Monad.State.Lazy, Control.Monad.State, Control.Monad.Reader, Control.Monad.List, Control.Monad.Except, Control.Monad.Error, Control.Monad.Cont, Control.Monad.RWS.Strict, Control.Monad.RWS.Lazy, Control.Monad.RWS, Control.Monad.Writer.Lazy, Control.Monad.Writer, Control.Monad.Writer.Strict, GHC.Base, Control.Monad | 
| joinCode | Language.Haskell.TH.Syntax, Language.Haskell.TH | 
| joinDrive |  | 
| 1 (Function) | System.FilePath.Posix, System.FilePath | 
| 2 (Function) | System.FilePath.Windows | 
| joinPath |  | 
| 1 (Function) | System.FilePath.Posix, System.FilePath | 
| 2 (Function) | System.FilePath.Windows | 
| joinProcessGroup | System.Posix.Process.ByteString, System.Posix.Process, System.Posix.ByteString, System.Posix | 
| Jp# | GHC.Integer.GMP.Internals | 
| JPNIC | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| JSON | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| Json | Distribution.Utils.Json | 
| JsonArray | Distribution.Utils.Json | 
| JsonBool | Distribution.Utils.Json | 
| JsonNull | Distribution.Utils.Json | 
| JsonNumber | Distribution.Utils.Json | 
| JsonObject | Distribution.Utils.Json | 
| JsonString | Distribution.Utils.Json | 
| jsSources |  | 
| 1 (Function) | Distribution.Types.BuildInfo, Distribution.PackageDescription | 
| 2 (Function) | Distribution.Types.BuildInfo.Lens, Distribution.Types.Lens | 
| julianMonthLength | Data.Time.Calendar.Julian | 
| JulianYearMonthDay | Data.Time.Calendar.Julian | 
| July | Data.Time.Calendar.MonthDay, Data.Time.Calendar.Julian, Data.Time.Calendar, Data.Time | 
| June | Data.Time.Calendar.MonthDay, Data.Time.Calendar.Julian, Data.Time.Calendar, Data.Time | 
| Just | Distribution.Compat.Prelude, Distribution.Compat.Prelude.Internal, GHC.Maybe, GHC.Base, Data.Maybe, Prelude | 
| justifyLeft |  | 
| 1 (Function) | Data.Text | 
| 2 (Function) | Data.Text.Lazy | 
| justifyLeftI | Data.Text.Internal.Fusion.Common | 
| justifyRight |  | 
| 1 (Function) | Data.Text | 
| 2 (Function) | Data.Text.Lazy | 
| justName | Language.Haskell.TH.Syntax | 
| JustS | Data.Map.Internal, Data.Map.Internal |