p (1..10).inject{ |r,e| p [r,e]; r*2}
# Result:
# [1, 2]
# [2, 3]
# [4, 4]
# [8, 5]
# [16, 6]
# [32, 7]
# [64, 8]
# [128, 9]
# [256, 10]
# 512p (1..10).inject{ |r,e| p [r,e]; r*2}
# Result:
# [1, 2]
# [2, 3]
# [4, 4]
# [8, 5]
# [16, 6]
# [32, 7]
# [64, 8]
# [128, 9]
# [256, 10]
# 512