Proposal: Add a type-bound policy factory to reduce generic repetition

[pedroddomingues]

Hi! Thanks for the great work on Gatehouse-TS.

While integrating the library, one DX issue stood out: the need to repeatedly specify
<User, Resource, Action, Context> every time we create policies or instantiate PermissionChecker.

Example today:

const policy = buildAbacPolicy<User, Resource, Action, Context>({ ... });

In larger projects this becomes boilerplate, increases visual noise, and can lead to inconsistent generics across files.

Suggested solution: a policy factory

Introduce something like:

const {
  buildAbacPolicy,
  buildRebacPolicy,
  buildAndPolicy,
  buildOrPolicy,
  PermissionChecker,
} = createPolicyFactory<User, Resource, Action, Context>();

So policy code becomes:

const policy = buildAbacPolicy({ ... });

Benefits:

• Removes repeated generics
• Preserves full type safety
• No breaking changes
• Works well even with multiple authorization domains

Would you be open to this improvement?
If yes, I can open a PR implementing the factory.

Thanks!

[9Morello]

@pedroddomingues That sounds pretty reasonable to me. I'm open to a PR implementing this. Ideally, the names could be adjusted a bit, so that in a big file, it's clear that we are using functions from a typed factory, and not just omitting the type parameters. Thank you for the suggestion!