package streams;

import java.util.List;

import java.util.Map;

import java.util.Optional;

import java.util.stream.IntStream;

import java.util.stream.Stream;

public class SimpleStream {

public static void main(String[] args) {

List<String> ls = List.of("Fred", "Jim", "Sheila");

Stream<String> ss = ls.stream();

ss

.filter(s -> s.length() > 3)

.forEach(s -> System.out.println(s));

ls.stream()

.forEach(s -> System.out.println(s));

// Stream.iterate(1, x -> x + 1)

// .forEach(x -> System.out.println(x));

// var result = Stream.iterate(1, x -> x + 1)

// .limit(10)

// .reduce(0, (a, b) -> a + b);

// .forEach(x -> System.out.println(x));

var result = IntStream.iterate(1, x -> x + 1)

.limit(0)

.reduce((a, b) -> a + b);

// System.out.println("sum is " + result);

result.ifPresentOrElse(x -> System.out.println("the sum is " + x),

() -> System.out.println("There wasn't any data"));

Map<String, String> names = Map.of("Fred", "Jones");

String first = "Freddy"; // assume a computation

// String last = names.get(first);

// String message = "Dear " + last.toUpperCase();

// System.out.println(message);

Optional.of(names)

.map(m -> m.get(first))

.map(l -> "Dear " + l.toUpperCase())

.ifPresentOrElse(x -> System.out.println(x), () -> System.out.println("No such client"));

}

}