Overloaded constants

• In particular, this works:

             163 + 13.5

• 163 gets the same type as 13.5 here

• An appropriate value is manufactured by an appropriate version of fromInteger

• No nonsense like this:

             double fahrenheit = 98.6;
             double celsius1 = 5/9 * (fahrenheit - 32);
             double celsius2 = (fahrenheit - 32) * 5/9;
                
             printf("%.1f\n%.1f\n", celsius1, celsius2);
                
             /* This is why we love C */
                
                          0.0
                          37.0        

• A constant like 163 actually has this type:

             (Num a) => a

• "Any type a, as long as it's an instance of Num."

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Copyright © 1999,2008 Mark Dominus