Missing Methods on public API types

[tamaro-skaljic]

Context Type	rng()	random()	sender()	sender_auth()	connection_id()	identity()	timestamp()
ProcedureContext	✅	✅	✅	❌	✅	✅	✅
ReducerContext	✅	✅	✅	✅	✅	✅	✅
ViewContext	❌	❌	✅	❌	❌	❌	❌
AnonymousViewContext	❌	❌	-	-	-	❌	❌

Context Type	as_anonymous_read_only()	as_read_only()
ProcedureContext	-	-
ReducerContext	✅	✅
ViewContext	❌	❌
AnonymousViewContext	❌	-

Also spacetimedb::LocalReadOnly should implement From<spacetimedb::Local>.

Could you tell me which of the ❌ should be fixed? I would create a PR then.

[joshua-spacetime]

Nothing's missing afaict. Each context type has a slightly different API.

[tamaro-skaljic]

@joshua-spacetime

The problem is that as a developer, I want to reuse code—but you don't offer trait abstractions and instead rely on plain structs.

If I want to reuse any function, it's almost impossible because ReducerContext, ViewContext, AnonymousViewContext, ProcedureContext and TxContext have, according to the type system, no common denominator.

I needed to abstract away all these differences here and here.

So I have some questions...

1: Why are Procedures allowed to access sender but not sender_auth? Especially because they can access it in a transaction because a TxContext transparently wraps a ReducerContext?

2: Why are Views allowed to access sender but not sender_auth?

3: Why are Views allowed to access sender but not connection_id?

4: Why are Views and AnonymousViews not allowed to access identity?

5: Why are Views and AnonymousViews not allowed to access timestamp?

6: Why are Views and AnonymousViews not allowed to access rng and random?

7: Why can't Views be casted to themself or AnonymousViews but Reducers can?

8: Why can't AnonymousViews be casted to themself but Reducers can?

9: Why can't spacetimedb::Local be casted to spacetimedb::LocalReadOnly?