for-loop.rb

pry(main)> show-method for_

From: (pry) @ line 0:
Number of lines: 6

def for_(var, cond, inc)
  while(cond.call)
    yield var
    inc.call
  end
end
pry(main)> for_(j=0, ->{j<3}, ->{j+=1}) { puts j }
0
1
2
=> nil