Prototype

The Prototype design pattern focuses on customization and the creation of objects that are similar but have slight variations. To gain a better understanding, let’s examine an example.

Consider a system that handles user management and permissions. We can represent a user using a data class, which might be structured as follows:

data class User(
    val name: String,
    val role: Role,
    val permissions: Set<String>,
) {
    fun hasPermission(permission: String) = permission in permissions
}

Each user must have a role, and each role has a set of permissions.

We’ll describe a role as an enum class:

enum class Role {
    ADMIN,
    SUPER_ADMIN,
    REGULAR_USER
}

Enum classes offer a convenient method for representing a collection of constants. This approach is advantageous compared to using strings to represent roles, as it allows for compile-time checks ensuring the existence of such objects. Additionally, using an enum allows...