Help understanding boundAPI in default.nix

[Admasnd]

I am attempting to understand ./default.nix in import-tree before I incorporate it in my nix setup and have a question about the definition of boundAPI on line 162.

What are the differences between the original definition of boundAPI vs these alternatives?

Original:
boundAPI = builtins.mapAttrs (_: g: g (self f)) __config.api;
Alternatives:
boundAPI = builtins.mapAttrs (_: g: g __config) __config.api;
boundAPI = builtins.mapAttrs (_: g: g self) self.api;

[vic]

Hey @Admasnd,

Feeling somewhat embarrassed at someone actually looking at the source code, haha. I'm sorry for the very bad names, I tried to expand with few comments and better variable names, hope it makes sense now.

See diff

[Admasnd]

No need to be embarrassed; I appreciate making such a cool library. Your updated code and comments were very helpful!

[vic]

g __config
g self

g does not take a config, but an import-tree object.

the difference is that a config is the accumulated state, and the import-tree object is: { __config, filter, map, etc } + boundAPI

[vic]

In this example from README:

import-tree.addAPI {
  maximal = self: self.addPath ./modules;
  feature = self: infix: self.maximal.filter (lib.hasInfix infix);
  minimal = self: self.feature "minimal";
}

g is each function like minimal, and minimal takes self so you can use APIs you've already added, like self.feature. So g does not takes a config internal state, but the import-tree itself.

[Admasnd]

Thank you for the additional explanation of the distinction between the config and tree-import object with respect to the functions.