Kas saaksite selgitada inline funktsioonide kontseptsiooni Kotlinis ja nende eeliseid?

In Kotlin, the inline keyword is used for functions so that the compiler, during compilation, inserts the body of the function directly at the call sites instead of a normal call by reference. This is especially useful for higher-order functions that accept lambda expressions.

Advantages of inline functions:

• Reducing function call overhead. When using lambdas without inline, objects and additional calls are created, which reduces performance.
• Performance improvement. Direct code insertion allows avoiding the creation of extra objects and calls.
• Ability to use noinline and crossinline. This allows flexible management of lambda behavior inside inline functions.

Example:

inline fun measureTime(block: () -> Unit) {
    val start = System.currentTimeMillis()
    block()
    val end = System.currentTimeMillis()
    println("Execution time: ${end - start} ms")
}

fun main() {
    measureTime {
        // some code
        Thread.sleep(100)
    }
}

Here, measureTime is an inline function, and the lambda body will be inserted directly, reducing additional costs.