nixpkgs/pkgs/development/interpreters/dhall/build-dhall-github-package.nix
Gabriel Gonzalez 459cf94991 Nixpkgs support for dhall-to-nixpkgs
The motivation for this change is to enable a new Dhall command-line
utility called `dhall-to-nixpkgs` which converts Dhall packages to
buildable Nix packages.  You can think of `dhall-to-nixpkgs` as the
Dhall analog of `cabal2nix`.

You can find the matching pull request for `dhall-to-nixpkgs` here:

https://github.com/dhall-lang/dhall-haskell/pull/1826

The two main changes required to support `dhall-to-nixpkgs` are:

* Two new `buildDhall{Directory,GitHub}Package` utilities are added

  `dhall-to-nixpkgs` uses these in the generated output

* `pkgs.dhallPackages` now selects a default version for each package
  using the `prefer` utility

  All other versions are still buildable via a `passthru` attribute
2020-06-17 15:57:21 +02:00

50 lines
1.2 KiB
Nix

{ buildDhallPackage, fetchFromGitHub, lib }:
# This function is used by `dhall-to-nixpkgs` when given a GitHub repository
lib.makeOverridable
( { # Arguments passed through to `buildDhallPackage`
name
, dependencies ? []
, source ? false
, # The directory containing the Dhall files, if other than the root of the
# repository
directory ? ""
, # The file to import, relative to the above directory
file ? "package.dhall"
# Arguments passed through to `fetchFromGitHub`
, owner
, repo
, rev
# Extra arguments passed through to `fetchFromGitHub`, such as the hash
# or `fetchSubmodules`
, ...
}@args:
buildDhallPackage {
inherit name dependencies source;
code =
let
src = fetchFromGitHub ({
name = "${name}-source";
inherit owner repo rev;
} // removeAttrs args [
"name"
"dependencies"
"source"
"directory"
"file"
"owner"
"repo"
"rev"
]);
prefix = lib.optionalString (directory != "") "${directory}/";
in
"${src}/${prefix}${file}";
}
)