/*

COPYRIGHT

Copyright 1992, 1993, 1994 Sun Microsystems, Inc.  Printed in the United
States of America.  All Rights Reserved.

This product is protected by copyright and distributed under the following
license restricting its use.

The Interface Definition Language Compiler Front End (CFE) is made
available for your use provided that you include this license and copyright
notice on all media and documentation and the software program in which
this product is incorporated in whole or part. You may copy and extend
functionality (but may not remove functionality) of the Interface
Definition Language CFE without charge, but you are not authorized to
license or distribute it to anyone else except as part of a product or
program developed by you or with the express written consent of Sun
Microsystems, Inc. ("Sun").

The names of Sun Microsystems, Inc. and any of its subsidiaries or
affiliates may not be used in advertising or publicity pertaining to
distribution of Interface Definition Language CFE as permitted herein.

This license is effective until terminated by Sun for failure to comply
with this license.  Upon termination, you shall destroy or return all code
and documentation for the Interface Definition Language CFE.

INTERFACE DEFINITION LANGUAGE CFE IS PROVIDED AS IS WITH NO WARRANTIES OF
ANY KIND INCLUDING THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS
FOR A PARTICULAR PURPOSE, NONINFRINGEMENT, OR ARISING FROM A COURSE OF
DEALING, USAGE OR TRADE PRACTICE.

INTERFACE DEFINITION LANGUAGE CFE IS PROVIDED WITH NO SUPPORT AND WITHOUT
ANY OBLIGATION ON THE PART OF Sun OR ANY OF ITS SUBSIDIARIES OR AFFILIATES
TO ASSIST IN ITS USE, CORRECTION, MODIFICATION OR ENHANCEMENT.

SUN OR ANY OF ITS SUBSIDIARIES OR AFFILIATES SHALL HAVE NO LIABILITY WITH
RESPECT TO THE INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY
INTERFACE DEFINITION LANGUAGE CFE OR ANY PART THEREOF.

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*/

#ifndef _UTL_STACK_UTL_STACK_HH
#define _UTL_STACK_UTL_STACK_HH


// utl_stack.hh - Defines the UTL_ScopeStack class - a stack of scopes
//
// UTL_ScopeStack implements scope nesting

/*
** DEPENDENCIES: utl_scope.hh
**
** USE: Included from util.hh
*/

// Forward declaration of active iterator for UTL_ScopeStack

class UTL_ScopeStackActiveIterator;

class UTL_ScopeStack
{

public:
   // Operations

   // Constructor and destructor
   UTL_ScopeStack();
   virtual ~UTL_ScopeStack();

   // Return top element
   virtual UTL_Scope *top();

   // Pop top element
   virtual void pop();

   // Clear entire stack
   virtual void clear();

   // Push an element on the stack and return stack
   virtual UTL_ScopeStack *push(UTL_Scope *el);

   // How deep is the stack now?
   virtual unsigned long depth();

   // Return bottom element
   virtual UTL_Scope *bottom();

   // Return (top - 1) element
   virtual UTL_Scope *next_to_top();

   // return topmost non-NULL element
   virtual UTL_Scope *top_non_null();

private:
   // Data
   UTL_Scope **pd_stack_data; // Store scopes stack
   unsigned long pd_stack_data_nalloced; // How many allocated?
   unsigned long pd_stack_top;  // How many used?

   // Friend active iterator class for UTL_ScopeStack

   friend class UTL_ScopeStackActiveIterator;
};

// Active iterator for UTL_ScopeStack

class UTL_ScopeStackActiveIterator
{

public:
   // Operations

   // Constructor
   UTL_ScopeStackActiveIterator(UTL_ScopeStack *s);

   virtual ~UTL_ScopeStackActiveIterator()
   {}

   // Advance to next element
   virtual void next();

   // Get current item
   virtual UTL_Scope *item();

   // Is the iteration finished?
   virtual long is_done();

private:
   // Data
   UTL_ScopeStack *source; // On what to iterate?
   long il;  // Where are we in iteration?
};

#endif           // _UTL_STACK_UTL_STACK_HH
