Limits the rate at which a closure is executed by preventing it's execution until a specified amount of time has elapsed.

Throttle.swift

import Foundation

/**
 Limits the rate at which a closure is executed by preventing it's execution until a specified amount of time has elapsed.

 Example:
 ```
 let fetchThrottle = Throttle(interval: 60)

 fetchThrottle {
    // doExpensiveOperation()
 }
 ```
 */
public class Throttle {
    public let interval: TimeInterval

    private var lastExecutionDate: Date?

    public init(interval: TimeInterval) {
        self.interval = interval
    }

    public func callAsFunction(_ operation: @escaping () -> Void) {
        let now = Date()
        if let lastExecutionDate, now.timeIntervalSince(lastExecutionDate) < interval {
            return
        }

        lastExecutionDate = now

        operation()
    }
}