fp1/week5/camil/Origami.icl

   1 module Origami
   2
   3 import StdEnv
   4
   5 Start                   = and
   6                                   [ sum`       [1 .. 5]                 == sum       [1 .. 5]
   7                                   , prod`      [1 .. 5]                 == prod      [1 .. 5]
   8                                   , flatten`   [[],[1],[1,2],[1,2,3]]   == flatten   [[],[1],[1,2],[1,2,3]]
   9                                   , reverse`   [1 .. 5]                 == reverse   [1 .. 5]
  10                                   , takeWhile` ((<>) 0) [1,2,3,0,4,5,6] == takeWhile ((<>) 0) [1,2,3,0,4,5,6]
  11                                   , maxList`   [1 .. 5]                 == maxList   [1 .. 5]
  12                                   ]
  13
  14 sum`                    = foldr (+) 0
  15 prod`                   = foldr (*) 1
  16 flatten`                = foldr (++) []
  17 length`                 = foldl (\l e = l + 1) 0
  18 reverse`                = foldl (\xs x = [x:xs]) []
  19 takeWhile` _ []         = []
  20 takeWhile` p xs
  21         | p (xs!!0)     = take (maxList [i \\ i <- [0..length xs-1] | foldr (&&) True [p (xs!!j) \\ j <- [0..i]]] + 1) xs
  22         | otherwise     = []
  23 maxList` []             = undef
  24 maxList` [x:xs]         = foldr max x xs