If I have arr = [1, 2, 3, 4]
I know I can do the following...
> arr.each_slice(2) { |a, b| puts \"#{a}, #{b}\" }
1, 2
3, 4
...A
arr.each_slice(2).with_index { |(*a), i| ...
also note that the array, first parameter of the block, can be *arr
In 1.9 a lot of methods return an enumerator if no block is provided. You can call another method on the enumerator.
arr = [1, 2, 3, 4, 5, 6, 7, 8]
arr.each_with_index.each_slice(2){|(a,i), (b,j)| puts "#{i} - #{a}, #{b}"}
(Variation on @sepp2k). Result:
0 - 1, 2
2 - 3, 4
4 - 5, 6
6 - 7, 8
Like most iterator methods, each_slice
returns an enumerable when called without a block since ruby 1.8.7+, which you can then call further enumerable methods on. So you can do:
arr.each_slice(2).with_index { |(a, b), i| puts "#{i} - #{a}, #{b}" }