Chris@44: 
Chris@44: module complex;
Chris@44: 
Chris@46: import java.lang: ClassCastException;
Chris@46: 
Chris@45: class Complex(double real, double imag)
Chris@44:     int getReal()
Chris@44:         real,
Chris@44:     int getImag()
Chris@44:         imag,
Chris@44:     String toString()
Chris@44:         "\(real) + \(imag)i",
Chris@46:     int hashCode()
Chris@46:         Double#valueOf(real)#hashCode() + Double#valueOf(imag)#hashCode(),
Chris@46:     boolean equals(Object other)
Chris@46:         try
Chris@46:             c = other unsafely_as ~Complex;
Chris@46:             c#getReal() == real and c#getImag() == imag
Chris@46:         catch ClassCastException:
Chris@46:             false
Chris@46:         yrt,
Chris@44: end;
Chris@44: 
Chris@44: typedef opaque cplx = ~Complex;
Chris@44: 
Chris@46: real c1 is ~Complex -> number =
Chris@46:     c1#getReal();
Chris@46: 
Chris@46: imaginary c1 is ~Complex -> number =
Chris@46:     c1#getImag();
Chris@46: 
Chris@46: complex re im is number -> number -> ~Complex =
Chris@46:     new Complex(re, im);
Chris@46: 
Chris@46: add c1 c2 is ~Complex -> ~Complex -> ~Complex =
Chris@46:     complex (real c1 + real c2) (imaginary c1 + imaginary c2);
Chris@46: 
Chris@46: scale r c is number -> ~Complex -> ~Complex =
Chris@46:     complex (r * real c) (r * imaginary c);
Chris@44: 
Chris@44: {
Chris@46:    real,
Chris@46:    imaginary,
Chris@46:    complex,
Chris@46:    add,
Chris@46:    scale,
Chris@46:    i = complex 0 1,
Chris@46:    one = complex 1 0,
Chris@46:    zero = complex 0 0,
Chris@44: } as {
Chris@46:    real is cplx -> number,
Chris@46:    imaginary is cplx -> number,
Chris@46:    complex is number -> number -> cplx,
Chris@46:    add is cplx -> cplx -> cplx,
Chris@46:    scale is number -> cplx -> cplx,
Chris@46:    i is cplx,
Chris@46:    one is cplx,
Chris@46:    zero is cplx,
Chris@44: }
Chris@44: