A simple type registration and instance hydration library.

This library was originally created to solve type hydration from message buses, as loosely shown in the example below, but has a wide variety of usages in other problem spaces.

// During setup.
hydration.Register[event.CustomerCreated]()

// During message bus serialization.
message.TypeKey = hydration.DerivedTypeKey[event.CustomerCreated]()

// During message bus deserialization.
typeKey := message.TypeKey
e := hydration.ResolveWithKey[event.Event](typeKey)

The unit of isolation in this package is the Registry. Users of this package can either create their own registry or use the global, default registry. Types are registered in registries using Type Keys, which are just strings used to look-up types.

There are 3 core operations exposed by this package:

• Register a new type in a registry.
• Resolve a concrete instance from a registry.
• Know if a registry has a registration for a type key.

For each of these operations, there are 4 different variants:

• Derived type key, default registry
• Custom type key, default registry
• Derived type key, custom registry
• Custom type key, custom registry

For example, Register uses derived type keys and the default registry, but RegisterIntoWithKey allows a custom registry and type key to be specified.