Data commit

Task/Queue-Definition/Standard-ML/queue-definition-1.ml

@@ -0,0 +1,12 @@
+signature QUEUE =
+sig
+  type 'a queue
+
+  val empty_queue: 'a queue
+
+  exception Empty
+
+  val enq: 'a queue -> 'a -> 'a queue
+  val deq: 'a queue -> ('a * 'a queue)
+  val empty: 'a queue -> bool
+end;

Task/Queue-Definition/Standard-ML/queue-definition-2.ml

@@ -0,0 +1,16 @@
+structure Queue:> QUEUE =
+struct
+  type 'a queue = 'a list
+
+  val empty_queue = nil
+
+  exception Empty
+
+  fun enq q x = q @ [x]
+
+  fun deq nil = raise Empty
+  |   deq (x::q) = (x, q)
+
+  fun empty nil = true
+  |   empty _ = false
+end;