| 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) | GHC.Boot.TH.Syntax, GHC.Internal.TH.Syntax, Language.Haskell.TH.Syntax, Language.Haskell.TH | 
| javaScript | GHC.Boot.TH.Lib, GHC.Internal.TH.Lib, Language.Haskell.TH.Lib, Language.Haskell.TH | 
| JavaScriptFFI |  | 
| 1 (Data Constructor) | Distribution.Simple, Language.Haskell.Extension | 
| 2 (Data Constructor) | GHC.LanguageExtensions, GHC.Boot.TH.Syntax, GHC.LanguageExtensions.Type, GHC.Internal.LanguageExtensions, GHC.Internal.TH.Syntax, Language.Haskell.TH.LanguageExtensions, Language.Haskell.TH.Syntax, Language.Haskell.TH | 
| javaStyle | Text.Parsec.Language, Text.ParserCombinators.Parsec.Language | 
| JHC | Distribution.Simple.Compiler, Distribution.Simple, Distribution.Compiler | 
| jhcProgram | Distribution.Simple.Program.Builtin, Distribution.Simple.Program | 
| Jn# | GHC.Integer.GMP.Internals | 
| join | Distribution.Compat.Prelude.Internal, Distribution.Compat.Prelude, Control.Monad, GHC.Base, GHC.Internal.Base, GHC.Internal.Control.Monad | 
| joinCode | GHC.Boot.TH.Monad, GHC.Internal.TH.Monad, Language.Haskell.TH.Syntax, Language.Haskell.TH | 
| joinDrive |  | 
| 1 (Function) | System.FilePath.Posix, System.FilePath | 
| 2 (Function) | System.FilePath.Windows | 
| 3 (Function) | System.OsPath.Posix.Internal | 
| 4 (Function) | System.OsPath.Posix | 
| 5 (Function) | System.OsPath | 
| 6 (Function) | System.OsPath.Windows.Internal | 
| 7 (Function) | System.OsPath.Windows | 
| joinModifiers | Graphics.Win32.Window.HotKey | 
| joinPath |  | 
| 1 (Function) | System.FilePath.Posix, System.FilePath | 
| 2 (Function) | System.FilePath.Windows | 
| 3 (Function) | System.OsPath.Posix.Internal | 
| 4 (Function) | System.OsPath.Posix | 
| 5 (Function) | System.OsPath | 
| 6 (Function) | System.OsPath.Windows.Internal | 
| 7 (Function) | System.OsPath.Windows | 
| joinProcessGroup | System.Posix.Process.ByteString, System.Posix.Process, System.Posix.Process.PosixString, System.Posix.PosixString, System.Posix.ByteString, System.Posix | 
| Jove | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| Jp# | GHC.Integer.GMP.Internals | 
| JPL_image | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| JPNIC | Distribution.SPDX.LicenseId, Distribution.SPDX | 
| JsCpp |  | 
| 1 (Type/Class) | GHC.Toolchain.Tools.Cpp, GHC.Toolchain | 
| 2 (Data Constructor) | GHC.Toolchain.Tools.Cpp, GHC.Toolchain | 
| jsCppProgram | GHC.Toolchain.Tools.Cpp, GHC.Toolchain | 
| jsemSupported | Distribution.Simple.Compiler, Distribution.Simple | 
| 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 | 
| jsppOptions |  | 
| 1 (Function) | Distribution.Types.BuildInfo, Distribution.PackageDescription | 
| 2 (Function) | Distribution.Types.BuildInfo.Lens, Distribution.Types.Lens | 
| 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 | 
| JUnneeded | Distribution.PackageDescription.Check | 
| Just | Distribution.Compat.Prelude.Internal, Distribution.Compat.Prelude, Data.Maybe, GHC.Base, GHC.Maybe, Prelude, GHC.Internal.Maybe, GHC.Internal.Base, GHC.Internal.Data.Maybe, GHC.Toolchain.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 |