nichts/parts/lib/default.nix

56 lines
2 KiB
Nix

{inputs, ...}: let
inherit (inputs.nixpkgs) lib;
# Define the base library to be extended. Not only will this be an extension
# of the nixpkgs library, but it will also be extensible the way nixpkgs lib
# is in case the extended library
# 1. needs to be extended internally
# 2. needs to be extended during outside consumption
# Additionally, .extend can be used to extend the lib with
# custom, composed functions.
lib0 = self: let
callLibs = file:
import file {
inherit inputs;
lib = self;
};
in {
extendedLib = {
builders = callLibs ./builders.nix;
modules = callLibs ./modules.nix;
};
# This makes mkSytem available *in addition* to `lib.extendedLib.builders.mkSystem`.
# The syntax is a matter of preference, but it is good to make sure all custom attribute
# sets (e.g., builders) are defined and taken from a separate attrset (extendedLib) to make
# absolutely sure we *never* conflict with nixpkgs. Likewise, the function names inherited
# here should also be different from ones available under `lib` by default, i.e., you cannot
# re-define functions.
# inherit (self.extendedLib) builders;
# inherit (self.extendedLib.builders) mkSystem;
};
# Merge layers of libraries into one as a subject of convenience
# and easy access.
extensions = lib.composeManyExtensions [
(_: _: inputs.nixpkgs.lib)
(_: _: inputs.flake-parts.lib)
];
# Extend default library
extendedLib = (lib.makeExtensible lib0).extend extensions;
# This can be used with `.extend` to extend the extended library.
in {
# Set the `lib` argument in `perSystem`, for example:
# ```
# perSystem = {pkgs, lib, ...}: { ...}
# ````
perSystem._module.args.lib = extendedLib;
# Prepare `lib` for external usage. This means it can be consumed
# from inputs.<name of this flake as an input>` by other flakes.
# `self` can also be used to access the custom lib as long as
# `flake.lib` is set.
flake = {
lib = extendedLib;
};
}