Hi,
<div><br></div><div>I am porting a C++ program to Haskell.  My current task is to take a class hierarchy and produce something equivalent in Haskell, but I don&#39;t seem to be able to get a grip on how type classes and instances contribute to the solution.  Can anyone enlighten me?</div>
<div><br></div><div>Roughly, the class hierarchy in C++ is of the form</div><div><br></div><div>class A {</div><div>public:</div><div>   virtual int do_x(int,int) = 0;</div><div>};</div><div><br></div><div>class B {</div>
<div>public:</div><div>   int do_x(int x,int y) { ...}</div><div>};</div><div><br></div><div>class C {</div><div>public:</div><div>   int do_x(int x,int y) { ...}</div><div>};</div><div><br></div><div>Any help would be greatly appreciated.</div>
<div><br></div><div>Thanks</div><div><br></div><div>Simon</div><div><a href="mailto:courtenage@gmail.com">courtenage@gmail.com</a></div><div><br></div><div><br></div>