ref

type FieldType struct {
	// Type of the field as a protobuf type value.
	Type *exprpb.Type

	// IsSet indicates whether the field is set on an input object.
	IsSet FieldTester

	// GetFrom retrieves the field value on the input object, if set.
	GetFrom FieldGetter
}

type TypeAdapter interface {
	// NativeToValue converts the input `value` to a CEL `ref.Val`.
	NativeToValue(value any) Val
}

type TypeProvider interface {
	// EnumValue returns the numeric value of the given enum value name.
	EnumValue(enumName string) Val

	// FindIdent takes a qualified identifier name and returns a Value if one exists.
	FindIdent(identName string) (Val, bool)

	// FindType looks up the Type given a qualified typeName. Returns false if not found.
	FindType(typeName string) (*exprpb.Type, bool)

	// FieldFieldType returns the field type for a checked type value. Returns false if
	// the field could not be found.
	FindFieldType(messageType, fieldName string) (*FieldType, bool)

	// NewValue creates a new type value from a qualified name and map of field name
	// to value.
	//
	// Note, for each value, the Val.ConvertToNative function will be invoked to convert
	// the Val to the field's native type. If an error occurs during conversion, the
	// NewValue will be a types.Err.
	NewValue(typeName string, fields map[string]Val) Val
}

type TypeRegistry interface {
	TypeAdapter
	TypeProvider

	// RegisterDescriptor registers the contents of a protocol buffer `FileDescriptor`.
	RegisterDescriptor(fileDesc protoreflect.FileDescriptor) error

	// RegisterMessage registers a protocol buffer message and its dependencies.
	RegisterMessage(message proto.Message) error

	// RegisterType registers a type value with the provider which ensures the
	// provider is aware of how to map the type to an identifier.
	//
	// If a type is provided more than once with an alternative definition, the
	// call will result in an error.
	RegisterType(types ...Type) error
}