week2/camil/TupleOverloading.icl

   1 implementation module TupleOverloading
   2
   3 import StdEnv
   4
   5 instance +    (a,b)   | + a & + b                where
   6         + (a,b) (c,d) = (a+c,b+d)
   7 instance +    (a,b,c) | + a & + b & + c          where
   8         + (a,b,c) (d,e,f) = (a+d,b+e,c+f)
   9
  10 instance -    (a,b)   | - a & - b                where
  11         - (a,b) (c,d) = (a-c,b-d)
  12 instance -    (a,b,c) | - a & - b & - c          where
  13         - (a,b,c) (d,e,f) = (a-d,b-e,c-f)
  14
  15 instance *    (a,b)   | * a & * b                where
  16         * (a,b) (c,d) = (a*c,b*d)
  17 instance *    (a,b,c) | * a & * b & * c          where
  18         * (a,b,c) (d,e,f) = (a*d,b*e,c*f)
  19
  20 instance /    (a,b)   | / a & / b                where
  21         / (a,b) (c,d) = (a/c,b/d)
  22 instance /    (a,b,c) | / a & / b & / c          where
  23         / (a,b,c) (d,e,f) = (a/d,b/e,c/f)
  24
  25 instance zero (a,b)   | zero a & zero b          where
  26         zero = (zero, zero)
  27 instance zero (a,b,c) | zero a & zero b & zero c where
  28         zero = (zero, zero, zero)
  29
  30 instance one  (a,b)   | one a & one b            where
  31         one = (one, one)
  32 instance one  (a,b,c) | one a & one b & one c    where
  33         one = (one, one, one)
  34
  35 instance ~    (a,b)   | ~ a & ~ b                where
  36         ~ (a,b) = (~ a, ~ b)
  37 instance ~    (a,b,c) | ~ a & ~ b & ~ c          where
  38         ~ (a,b,c) = (~ a, ~ b, ~ c)
  39
  40 Start  = (test (1,2), test (1,2,3))
  41
  42 test a = ( zero + a == a    && a    == a + zero
  43          , a - zero == a    && a    == ~ (zero - a)
  44          ,  one * a == a    && a    == a * one
  45          , zero * a == zero && zero == a * zero
  46          ,  a / one == a
  47          ,  ~ (~ a) == a
  48          )