AnimalShelter/shelter/registry.go

package shelter

import (
	"fmt"
	"sync"
)

type AnimlConstructor func() Animal

var (
	registrMu sync.RWMutex
	registry  = make(map[string]AnimlConstructor)
)

func Register(typeName string, constructor AnimlConstructor) {
	registrMu.Lock()
	defer registrMu.Unlock()
	registry[typeName] = constructor
}

func Create(typeName string) (Animal, error) {
	registrMu.RLock()
	defer registrMu.RUnlock()
	constructor, ok := registry[typeName]
	if !ok {
		return nil, fmt.Errorf("animl %s is not registered", typeName)
	}
	return constructor(), nil
}