functional-programming

class Timer
  def self.measure
    start_time = Time.now
    yield if block_given?
    end_time = Time.now
    end_time - start_time

# Gemfile
gem 'dry-types'
gem 'dry-struct'

require 'dry-types'
require 'dry-struct'

// Sample data
const numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
const users = [
  { id: 1, name: 'Alice', age: 25, active: true },
  { id: 2, name: 'Bob', age: 30, active: false },
  { id: 3, name: 'Charlie', age: 35, active: true },

# Map - transform elements
[1, 2, 3, 4].map { |n| n * 2 }          # => [2, 4, 6, 8]
['alice', 'bob'].map(&:upcase)          # => ['ALICE', 'BOB']
users.map(&:email)                       # => ['alice@example.com', ...]

# Select/Reject - filter elements

package com.example.demo.examples;

import java.util.*;
import java.util.stream.Collectors;

public class StreamExamples {