int fibonaccit(int n)
  a = 0
  b = 1
  while( n > 1 )
    tmp = a
    a = b
    b = tmp + b
    puts(b)
    n = n - 1
  end
end
-- -- --
s(:list,  [s(:function,  :int, 
  s(:name,  "fibonaccit"), 
  s(:parameters, 
    s(:field,  :int,  :n)), 
  s(:expressions, 
    s(:assign, 
      s(:name,  "a"), 
      s(:int,  0)), 
    s(:assign, 
      s(:name,  "b"), 
      s(:int,  1)), 
    s(:while, 
      s(:condition, 
        s(:operator,  ">", 
          s(:name,  "n"), 
          s(:int,  1))), 
      s(:expressions, 
        s(:assign, 
          s(:name,  "tmp"), 
          s(:name,  "a")), 
        s(:assign, 
          s(:name,  "a"), 
          s(:name,  "b")), 
        s(:assign, 
          s(:name,  "b"), 
          s(:operator,  "+", 
            s(:name,  "tmp"), 
            s(:name,  "b"))), 
        s(:call, 
          s(:name,  "puts"), 
          s(:arguments, 
            s(:name,  "b"))), 
        s(:assign, 
          s(:name,  "n"), 
          s(:operator,  "-", 
            s(:name,  "n"), 
            s(:int,  1)))))))])