-- Code of Figure 9.9, pages 377-378 from
-- Kenneth C. Louden, Programming Languages
-- Principles and Practice 2nd Edition
-- Copyright (C) Brooks-Cole/ITP, 2003

package body ComplexNumbers is

type ComplexRecord is record
   re, im: Float;
end record;

function "+"(x,y: in Complex) return Complex is
t: Complex;
begin
   t := new ComplexRecord;
   t.re := x.re + y.re;
   t.im := x.im + y.im;
   return t;
end "+";

-- more operations here

function makeComplex (x,y: in Float)
      return Complex is
begin
   return new ComplexRecord'(re => x , im => y);
end makeComplex;

function realPart (z: in Complex) return Float is
begin
   return z.re;
end realPart;

function imaginaryPart (z: in Complex) 
   return Float is
begin
   return z.im;
end imaginaryPart;

end ComplexNumbers;