ghci
Interactive REPL environment for Haskell
TLDR
Start interactive session
$ ghci
Load a file$ ghci [file.hs]
Load module in session$ :load [file.hs]
Get type of expression$ :type [expression]
Reload current module$ :reload
SYNOPSIS
ghci [options] [files]
DESCRIPTION
ghci is the interactive environment for GHC (Glasgow Haskell Compiler). It provides a REPL for evaluating Haskell expressions, loading modules, and exploring types interactively.GHCi supports all GHC language extensions and can compile modules on the fly. It provides introspection commands for examining types, kinds, and documentation. Tab completion and command history enhance usability.
PARAMETERS
FILES
Haskell files to load.:load FILE
Load a module.:reload
Reload current modules.:type, :t EXPR
Show expression type.:kind, :k TYPE
Show the kind of a type.:info NAME
Show info about name, including definition and instances.:browse MODULE
List identifiers exported by a module.:set OPTION
Set a GHCi or compiler option for the session.:main ARGS
Run the program's `main` with the given arguments.:quit, :q
Exit GHCi.-i DIR1:...:DIRn
Add directories to the source file search path.--help
Display help information.
CONFIGURATION
~/.ghci
Per-user startup file loaded when GHCi starts, containing default settings, imports, and custom commands../.ghci
Project-local startup file loaded after the user file (must have safe permissions to be read).
INSTALL
sudo apt install ghc
sudo dnf install ghc
sudo pacman -S ghc
sudo apk add ghc
sudo zypper install ghc
brew install ghc
nix profile install nixpkgs#ghc
CAVEATS
Some compiled code may behave differently in interpreter. Memory usage can grow with large expressions. Restart clears interpreter state.
HISTORY
GHCi was introduced with GHC 5.0 in 2001, providing interactive Haskell evaluation alongside the batch compiler.
