From fd3eca3371b0284553e8e0a855f2bb1c09165be9 Mon Sep 17 00:00:00 2001
From: Camil Staps
Date: Tue, 19 Sep 2017 17:54:01 +0200
Subject: Start file assignment 2

---
 assignment-2/serialize2start.icl | 87 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 assignment-2/serialize2start.icl

(limited to 'assignment-2')

diff --git a/assignment-2/serialize2start.icl b/assignment-2/serialize2start.icl
new file mode 100644
index 0000000..14e0037
--- /dev/null
+++ b/assignment-2/serialize2start.icl
@@ -0,0 +1,87 @@
+module serialize2start
+
+/*
+  Definition for assignment 2 in AFP 2017
+  Pieter Koopman pieter@cs.ru.nl
+  September 2017
+*/
+
+import StdEnv, StdMaybe
+
+class serialize a where
+  write :: a [String] -> [String]
+  read  :: [String] -> Maybe (a,[String])
+
+instance serialize Bool where
+  write b c = [toString b:c]
+  read ["True":r]  = Just (True,r)
+  read ["False":r] = Just (False,r)
+  read _ = Nothing
+
+instance serialize Int where
+  write i c = [toString i:c]
+  read [s:r]
+    # i = toInt s
+    | s == toString i
+      = Just (i,r)
+      = Nothing
+  read _ = Nothing
+
+// ---
+
+:: UNIT       = UNIT
+:: EITHER a b = LEFT a | RIGHT b
+:: PAIR   a b = PAIR a b
+:: CONS   a   = CONS String a
+
+// ---
+
+:: ListG a :== EITHER (CONS UNIT) (CONS (PAIR a [a]))
+
+instance serialize [a] | serialize a where  // to be imporved
+  write l c = c
+  read l = Nothing
+
+:: Bin a = Leaf | Bin (Bin a) a (Bin a)
+:: BinG a :== EITHER (CONS UNIT) (CONS (PAIR (Bin a) (PAIR a (Bin a))))
+
+instance serialize (Bin a) | serialize a where // to be imporved
+  write a c = c
+  read l = Nothing
+
+instance == (Bin a) | == a where // better use the generic approach
+  (==) Leaf Leaf = True
+  (==) (Bin l a r) (Bin k b s) = l == k && a == b && r == s
+  (==) _ _ = False
+
+// ---
+
+Start = 
+  [test True
+  ,test False
+  ,test 0
+  ,test 123
+  ,test -36
+  ,test [42]
+  ,test [0..4]
+  ,test [[True],[]]
+  ,test (Bin Leaf True Leaf)
+  ,test [Bin (Bin Leaf [1] Leaf) [2] (Bin Leaf [3] (Bin Leaf [4,5] Leaf))]
+  ,test [Bin (Bin Leaf [1] Leaf) [2] (Bin Leaf [3] (Bin (Bin Leaf [4,5] Leaf) [6,7] (Bin Leaf [8,9] Leaf)))]
+  ]
+
+test :: a -> ([String],[String]) | serialize, == a
+test a = 
+  (if (isJust r)
+    (if (fst jr == a)
+      (if (isEmpty (tl (snd jr)))
+        ["Oke "]
+        ["Fail: not all input is consumed! ":snd jr])
+      ["Fail: Wrong result ":write (fst jr) []])
+    ["Fail: read result is Nothing "]
+  , ["write produces ": s]
+  )
+  where
+    s = write a ["\n"]
+    r = read s
+    jr = fromJust r
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