package fixtures

data class Person(
    val id: Int,
    val name: String,
    val email: String
)

class Repository<T> {
    private val items = mutableMapOf<Int, T>()

    fun add(key: Int, item: T) {
        items[key] = item
    }

    fun find(key: Int): T? = items[key]

    fun getAll(): List<T> = items.values.toList()
}

fun add(a: Int, b: Int): Int = a + b

fun <T> filter(items: List<T>, predicate: (T) -> Boolean): List<T> {
    return items.filter(predicate)
}

fun main() {
    val repo = Repository<Person>()
    repo.add(1, Person(1, "Alice", "alice@example.com"))
    repo.add(2, Person(2, "Bob", "bob@example.com"))

    repo.getAll().forEach { println(it) }
    println("3 + 4 = ${add(3, 4)}")

    val numbers = listOf(1, 2, 3, 4, 5)
    val evens = filter(numbers) { it % 2 == 0 }
    println("Evens: $evens")
}