yang.model.api.TypeDefinition has a problem, which is its inherent tie-in with yang-data-api representation – via its getDefaultValue() method. It also implies SchemaNode in its hierarchy, which is largely unused in yang-data-api users interacting with TypeDefinition.

Define a new interface, yang.data.api.type.NormalizedType, which will expose the same information as yang.model.api.TypeDefinition. The interface hierarchy should capture the base YANG types, such there is a yang.data.api.type.Uint8Type, etc. mirroring yang.model.api.type. Note the base interface should not be generic.

Return this type from DataSchemaContext.SimpleValue#type().