ghciwatch

Ghciwatch loads a GHCi session for a Haskell project and reloads it when source files change.

Features

  • GHCi output is displayed to the user as soon as it’s printed.
  • Ghciwatch can handle new modules, removed modules, or moved modules without a hitch
  • A variety of lifecycle hooks let you run Haskell code or shell commands on a variety of events.
  • Custom globs can be supplied to reload or restart the GHCi session when non-Haskell files (like templates or database schema definitions) change.
  • Ghciwatch can clear the screen between reloads.
  • Compilation errors can be written to a file with --error-file, for compatibility with ghcid’s --outputfile option.
  • Comments starting with -- $> can be evaluated in GHCi.
    • Eval comments have access to the top-level bindings of the module they’re defined in, including unexported bindings.
    • Multi-line eval comments are supported with {- $> ... <$ -}.

Demo

Check out an asciinema demo to see how ghciwatch feels in practice: