forked from extern/flakelight
ff24d5d433
In addition to a regular bundler of the form `x: x`, this allows setting bundler options to a function of the form `pkgs: x: x` which is passed the package set for the system (for example: `{ hello, ... }: x: hello` to always return hello). This allows, in particular, an autoloaded bundler in its own file to access the package set. This is non-trivial as we must tell `x: x` and `pkgs: x: x` apart. Fortunately, given some derivation `drv`, `pkgs // drv` is a valid derivation and a set with attr names matching pkgs. When applying this to the function, if it returns a derivation, it was of the `x: x` form, and if it returns a function, it was of the `pkgs: x: x` form. In order to prevent IFD when evaluating the flake if the bundler is of form `x: x` and uses IFD, we determine the form and apply pkgs when applying the bundler instead of during flake evaluation. This is done by wrapping the bundler. Of note, we cannot rely on `builtins.functionArgs`, since `pkgs: { hello, ... }: (x: hello) pkgs` is the same as the inner function but with args hidden.
39 lines
947 B
Nix
39 lines
947 B
Nix
# flakelight -- Framework for simplifying flake setup
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# Copyright (C) 2023 Archit Gupta <archit@accelbread.com>
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# SPDX-License-Identifier: MIT
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{ config, lib, flakelight, ... }:
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let
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inherit (lib) isFunction mapAttrs mkMerge mkOption mkIf;
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inherit (lib.types) lazyAttrsOf nullOr;
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inherit (flakelight.types) function optFunctionTo;
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wrapBundler = pkgs: bundler: drv:
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if isFunction (bundler (pkgs // drv)) then bundler pkgs drv else bundler drv;
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in
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{
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options = {
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bundler = mkOption {
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type = nullOr function;
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default = null;
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};
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bundlers = mkOption {
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type = nullOr (optFunctionTo (lazyAttrsOf function));
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default = { };
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};
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};
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config = mkMerge [
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(mkIf (config.bundler != null) {
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bundlers.default = config.bundler;
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})
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(mkIf (config.bundlers != null) {
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perSystem = pkgs: {
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bundlers = mapAttrs (_: wrapBundler pkgs) (config.bundlers pkgs);
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};
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})
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];
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}
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