New module

perezzini · Sep 27, 2017 · 0530652 · 0530652
1 parent b2846f7
commit 0530652
Show file tree

Hide file tree

Showing 2 changed files with 24 additions and 0 deletions.
diff --git a/tigerpila.sig b/tigerpila.sig
@@ -0,0 +1,11 @@
+signature tigerpila =
+sig
+
+type 'a Pila
+val nuevaPila : unit -> 'a Pila
+val nuevaPila1 : 'a -> 'a Pila
+val pushPila : 'a Pila -> 'a -> unit
+val popPila : 'a Pila -> unit
+val topPila : 'a Pila -> 'a
+
+end
diff --git a/tigerpila.sml b/tigerpila.sml
@@ -0,0 +1,13 @@
+structure tigerpila :> tigerpila =
+struct
+
+type 'a Pila = 'a list ref
+fun nuevaPila() = ref []
+fun nuevaPila1 e = ref [e]
+fun pushPila pila item = pila:=(item::(!pila))
+fun popPila pila =
+	let	val ret = hd(!pila)
+	in pila:=tl(!pila) end
+fun topPila pila = hd(!pila)
+
+end