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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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README.md
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README.md
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When a module like `flake.modules.nixos.foo` is requested (for example, included in a `nixosConfiguration`), a corresponding module is computed from `flake.aspects.foo.nixos`.
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`flake.aspects.foo.includes` is a list of functions (providers) that are called with `{ aspect-chain = ["foo"]; class = "nixos" }`. These providers return another aspect that provides a module of the same `class` (in this case, `nixos`).
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`flake.aspects.foo.includes` is a list of functions (providers). A **provider** is a function `{ class, aspect-chain } => <aspect-object>`. They are called with `{ aspect-chain = ["foo"]; class = "nixos" }`. These providers return an aspect object that contains a module of the same `class` (in this case, `nixos`).
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Providers answer the question: given we have `nixos` modules from `[foo]` aspects, what other aspects can provide `nixos` modules that need to be imported?
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This means that the included aspect determines which configuration its caller should use.
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By default, all aspects have a `<aspect>.provides.itself` provider function that ignores its argument and returns the `<aspect>` itself. This is why `with aspects; [ bar baz ]` works: it is shorthand for `[ aspects.bar.provides.itself aspects.baz.provides.itself ]`.
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By default, all aspects have an `<aspect>.provides.itself` provider function that always returns the `<aspect>` itself. This is why `with aspects; [ bar baz ]` works: it is shorthand for `[ aspects.bar.provides.itself aspects.baz.provides.itself ]`. It is possible to override the default provider, by setting `__functor`, see how [test](https://github.com/vic/flake-aspects/blob/4f88b4ecefbe46ccfa5d9cfa11451a88be169a70/checkmate.nix#L270) or [vic/den](https://github.com/vic/den/blob/def1c396e7ce884578d6589391cca8a4c6a650d3/nix/aspects-config.nix#L55) do it.
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##### Dynamic modules using provider function's `{ aspect-chain, class }` argument.
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You can also define custom providers that inspect the `aspect-chain` and `class` arguments and return a set of modules accordingly. This allows providers to act as proxies or routers for dependencies.
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You can also define custom providers that inspect the `aspect-chain` and `class` values and return a set of modules accordingly. This allows providers to act as conditional proxies or routers for dependencies.
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```nix
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flake.aspects.kde-desktop.provides.karousel = { aspect-chain, class }:
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##### Parametrized modules from providers.
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Providers can be curried like any function, this way you can provide parametrized modules.
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Providers can be curried (but *must* use explicit argument names). This lets you have
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modules parametrized by some values, outside the aspect scope. For a real-world
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usage of this feature, see how `vic/den` [defines](https://github.com/vic/den/blob/def1c396e7ce884578d6589391cca8a4c6a650d3/nix/aspects-config.nix#L40) `flake.aspects.default.host` and their [use](https://github.com/vic/den/blob/def1c396e7ce884578d6589391cca8a4c6a650d3/templates/default/modules/_example/aspects.nix#L32).
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```nix
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flake.aspects = { aspects, ... }: {