nixpkgs/pkgs/development/interpreters/dhall/build-dhall-directory-package.nix

{ buildDhallPackage, lib }:

# This is a minor variation on `buildDhallPackage` that splits the `code`
# argument into `src` and `file` in such a way that you can easily override
# the `file`
#
# This function is used by `dhall-to-nixpkgs` when given a directory
lib.makePackageOverridable
  ( { # Arguments passed through to `buildDhallPackage`
      name
    , dependencies ? []
    , source ? false

    , src
    , # The file to import, relative to the root directory
      file ? "package.dhall"
      # Set to `true` to generate documentation for the package
    , document ? false
    }:

    buildDhallPackage
      ( { inherit name dependencies source;

          code = "${src}/${file}";

        }
      // lib.optionalAttrs document { documentationRoot = src; }
      )
  )