tldr/pages/common/ghcid.md

ghcid

Simple and efficient CLI IDE for Haskell that reloads code on file changes. Continuously displays compile errors, warnings, and test results. More information: https://github.com/ndmitchell/ghcid.

• Start ghcid and monitor a Haskell file for changes:

ghcid {{path/to/Main.hs}}

• Start ghcid with a specific command, such as loading a Stack or Cabal project:

ghcid --command "{{stack ghci Main.hs}}"

• Run an action (default main) on each file save:

ghcid --run={{action}} {{path/to/Main.hs}}

• Set maximum height and width (default to console height and width):

ghcid --height={{height}} --width={{width}} {{path/to/Main.hs}}

• Write full GHC compiler output to a file:

ghcid --outputfile={{path/to/output_file.txt}} {{path/to/Main.hs}}

• Execute REPL commands (eg. -- $> 1+1) on each file save:

ghcid --allow-eval {{path/to/Main.hs}}