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fake.modules transposition for aspect-oriented Dendritic Nix. with cross-aspect dependencies. Discussions: https://oeiuwq.zulipchat.com/join/nqp26cd4kngon6mo3ncgnuap/
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dendritic
nix
aspect
oriented
1lib:
2# An utility for creating new aspect configuration classes that
3# help with separation of concerns.
4#
5# `forward` is a function that generates an aspect
6# that imports configurations from an originClass into
7# an scoped submodule of another targetClass.
8#
9# It takes te following arguments:
10#
11# - each: listOf items.
12# - fromClass: item -> originClassName.
13# - intoClass: item -> targetClassName.
14# - intoPath: item -> [ submoduleAttrPath ].
15# - fromAspect: item -> aspect. An aspect to resolve origin class modules from.
16#
17# This is particularly useful for per-user homeManager like
18# configurations.
19#
20# The following pseudo-code snippet is used by [den](https://github.com/vic/den)
21# to support homeManager classes on NixOS.
22#
23# hmSupport = { host }: forward {
24# each = host.users;
25# fromClass = _user: "homeManager"; # originClass could have depended on user.
26# intoClass = _user: "nixos"
27# intoPath = user: [ "home-manager" "users" user.userName ] # HM users submodule.
28# fromAspect = user: den.aspects.${user.userName}; # resolve originClass from user aspect.
29# }
30#
31#
32# den.aspects.my-host.includes = [ hmSupport ];
33# den.aspects.my-user = {
34# homeManager = { }; # settings for nixos.home-manager.users.my-user submodule.
35# }
36#
37# However usage is not limited to HM, and this settings forwarding ability
38# can be used for other use cases.
39#
40# See checkmate/modules/tests/forward.nix for working example.
41#
42{
43 each,
44 fromClass,
45 intoClass,
46 intoPath,
47 fromAspect,
48}:
49let
50 include =
51 item:
52 let
53 from = fromClass item;
54 into = intoClass item;
55 path = intoPath item;
56 aspect = fromAspect item;
57 module = aspect.resolve { class = from; };
58 config = lib.setAttrByPath path (
59 { ... }:
60 {
61 imports = [ module ];
62 }
63 );
64 in
65 {
66 ${into} = config;
67 };
68in
69{
70 includes = map include each;
71}