Hy {#sec-language-hy}#

Installation {#ssec-hy-installation}#

Installation without packages {#installation-without-packages}#

You can install hy via nix-env or by adding it to configuration.nix by referring to it as a hy attribute. This kind of installation adds hy to your environment and it successfully works with python3.

::: {.caution} Packages that are installed with your python derivation, are not accessible by hy this way. :::

Installation with packages {#installation-with-packages}#

Creating a hy derivation with custom python packages is really simple and similar to the way that python does it. The attribute hy provides the function withPackages that creates a custom hy derivation with specified packages.

For example, if you want to create a shell with matplotlib and numpy, you can do it like so:

$ nix-shell -p "hy.withPackages (ps: with ps; [ numpy matplotlib ])"

Or if you want to extend your configuration.nix:

{
  # ...

  environment.systemPackages = with pkgs; [
    (hy.withPackages (
      py-packages: with py-packages; [
        numpy
        matplotlib
      ]
    ))
  ];
}