week3/camil/StdStack.icl

   1 implementation module StdStack
   2
   3 import StdEnv
   4
   5 :: Stack a :== [a]
   6
   7 newStack :: (Stack a)
   8 newStack = []
   9
  10 push :: a (Stack a) -> (Stack a)
  11 push a s = s ++ [a]
  12
  13 pop
  14
  15 Start  = ( "s0 = newStack = ",        s0,'\n'
  16          , "s1 = push 1 s0 = ",       s1,'\n'
  17          , "s2 = pushes [2..5] s1 = ",s2,'\n'
  18          , "s3 = pop s2 = ",          s3,'\n'
  19          , "s4 = popn 3 s3 = ",       s4,'\n'
  20          , "s5 = top s4 = ",          s5,'\n'
  21          , "s6 = topn 3 s2 = ",       s6,'\n'
  22          , "s7 = elements s2 = ",     s7,'\n'
  23          )
  24 where
  25         s0 = newStack
  26         s1 = push 1 s0
  27         s2 = pushes [2..5] s1
  28         s3 = pop s2
  29         s4 = popn 3 s3
  30         s5 = top s4
  31         s6 = topn 3 s2
  32         s7 = elements s2