map and lazy_map

hoge.rb

[1] pry(main)> (1..10).map { |n| puts(n); n }.map { |n| puts(n); n }
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
10
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
[2] pry(main)> (1..10).lazy.map { |n| puts(n); n }.map { |n| puts(n); n }.force
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
10
10
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]