--- parser3/src/include/pa_stack.h	2003/03/04 15:59:18	1.17.2.6
+++ parser3/src/include/pa_stack.h	2003/07/24 11:31:21	1.18
@@ -8,7 +8,7 @@
 #ifndef PA_STACK_H
 #define PA_STACK_H
 
-static const char* IDENT_STACK_H="$Date: 2003/03/04 15:59:18 $";
+static const char* IDENT_STACK_H="$Date: 2003/07/24 11:31:21 $";
 
 #include "pa_config_includes.h"
 #include "pa_array.h"
@@ -27,23 +27,28 @@ public:
 		ftop++;
 	}
 
-	/// @test to think: freeing unused stack item right now, may no do that? 
-	/// [delay that till next push?]
 	T pop() {
-		T result=get(--ftop);
-		put(ftop, empty); 
-		return result;
+		return get(--ftop);
 	}
 
-	int top_index() { return ftop-1; }
-	void top_index(int top_index) { ftop=top_index+1; }
-	T top_value() { return get(top_index()); }
-
-private:
-
-	// deepest used index
-	int ftop;
-	T empty;
+	bool is_empty() { return ftop==0; }
+	size_t top() { return ftop; }
+	void top(size_t atop) { ftop=atop; }
+	T upper_value() { 
+		assert(!is_empty());
+		return get(ftop-1); 
+	}
+
+	/// call this prior to collecting garbage [in unused part of stack there may be pointers(unused)]
+	void wipe_unused() {
+		if(!is_full())
+			memset(&felements[fused], 0, (fallocated-fused)*sizeof(T));
+	}
+
+protected:
+
+	// deepest used index+1
+	size_t ftop;
 };
 
 #endif