next

Returns the next object in the enumerator, and move the internal position forward. When the position reached at the end, StopIteration is raised.

a = [1,2,3]
e = a.to_enum
p e.next   #=> 1
p e.next   #=> 2
p e.next   #=> 3
p e.next   #raises StopIteration

Note that enumeration sequence by next method does not affect other non-external enumeration methods, unless underlying iteration methods itself has side-effect, e.g. IO#each_line.