gen-bind

gen-bind is module binding with external arguments for Nix — partial application of bindings into NixOS module functions, with closure-based injection, collision detection with blame, lazy contracts, and thunk resolution for config-dependent values.

The problem it owns: a module function that needs host or user in scope, and a value for that argument that isn’t known until later, is an ordinary problem in a framework built on modules. gen-bind wraps the module and the binding together, resolves the thunk when the value finally exists, and tells you by name — not by a silent wrong merge — when two bindings collide.

It depends on gen-graph and gen-prelude. One roster member builds on it: gen-settings, which resolves settings schemas through gen-bind’s binding surface.

Take it alone

{
  inputs.gen-bind.url = "github:sini/gen-bind";
  # gen-bind's only dependency is gen-prelude, pulled in transitively.

  outputs = { gen-bind, ... }:
    let
      genBind = gen-bind.lib;
    in {
      wrappedModule = (genBind.wrap {
        module = { host, config, lib, ... }: {
          networking.hostName = host.name;
        };
        bindings = { host = { name = "igloo"; }; };
      }).module;
    };
}