--- parser3/src/include/pa_stack.h	2001/03/10 16:34:35	1.5
+++ parser3/src/include/pa_stack.h	2004/02/11 15:33:14	1.22
@@ -1,41 +1,54 @@
-/*
-	Parser
-	Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com)
-	Author: Alexander Petrosyan <paf@design.ru>
+/** @file
+	Parser: stack class decl.
 
-	$Id: pa_stack.h,v 1.5 2001/03/10 16:34:35 paf Exp $
+	Copyright (c) 2001-2004 ArtLebedev Group (http://www.artlebedev.com)
+	Author: Alexandr Petrosian <paf@design.ru> (http://paf.design.ru)
 */
 
 #ifndef PA_STACK_H
 #define PA_STACK_H
 
+static const char * const IDENT_STACK_H="$Date: 2004/02/11 15:33:14 $";
+
+#include "pa_config_includes.h"
 #include "pa_array.h"
 
-class Stack : public Array {
+/// simple stack based on Array
+template<typename T> class Stack: public Array<T> {
 public:
 
-	Stack(Pool& apool) : Array(apool), ftop(0) {
-	}
+	Stack(): ftop(0) {}
 
-	void push(Item *item) {
-		if(ftop<size()) // cell is already allocated?
+	void push(T item) {
+		if(ftop<count()) // cell is already allocated?
 			put(ftop, item); // use it
 		else
 			*this+=item; // append it
 		ftop++;
 	}
-	Item *pop() {
+
+	T pop() {
 		return get(--ftop);
 	}
 
-	int top_index() { return ftop-1; }
-	Item *top_value() { return get(top_index()); }
+	bool is_empty() { return ftop==0; }
+	size_t top_index() { return ftop; }
+	void set_top_index(size_t atop) { ftop=atop; }
+	T top_value() { 
+		assert(!is_empty());
+		return get(ftop-1); 
+	}
 
-private:
+	/// call this prior to collecting garbage [in unused part of stack there may be pointers(unused)]
+	void wipe_unused() {
+		if(size_t above_top_size=fused-ftop)
+			memset(&felements[ftop], 0, above_top_size*sizeof(T));
+	}
 
-	// deepest used index
-	int ftop;
+protected:
 
+	// deepest used index+1
+	size_t ftop;
 };
 
 #endif