ref fibonaccit(int n)
  a = 0
  while(n)
    some = 43
    other = some * 4
  end
end
-- -- --
s(:expressions, 
  s(:function,  :ref, 
    s(:name,  :fibonaccit), 
    s(:parameters, 
      s(:field,  :int,  :n)), 
    s(:expressions, 
      s(:assign, 
        s(:name,  :a), 
        s(:int,  0)), 
      s(:while, 
        s(:condition, 
          s(:name,  :n)), 
        s(:expressions, 
          s(:assign, 
            s(:name,  :some), 
            s(:int,  43)), 
          s(:assign, 
            s(:name,  :other), 
            s(:operator,  "*", 
              s(:name,  :some), 
              s(:int,  4))))))))