/**

 * vim: set ts=4 :

 * =============================================================================

 * SourceMod (C)2004-2008 AlliedModders LLC.  All rights reserved.

 * =============================================================================

 *

 * This file is part of the SourceMod/SourcePawn SDK.

 *

 * This program is free software; you can redistribute it and/or modify it under

 * the terms of the GNU General Public License, version 3.0, as published by the

 * Free Software Foundation.

 * 

 * This program is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more

 * details.

 *

 * You should have received a copy of the GNU General Public License along with

 * this program.  If not, see <http://www.gnu.org/licenses/>.

 *

 * As a special exception, AlliedModders LLC gives you permission to link the

 * code of this program (as well as its derivative works) to "Half-Life 2," the

 * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software

 * by the Valve Corporation.  You must obey the GNU General Public License in

 * all respects for all other code used.  Additionally, AlliedModders LLC grants

 * this exception to all derivative works.  AlliedModders LLC defines further

 * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),

 * or <http://www.sourcemod.net/license.php>.

 *

 * Version: $Id$

 */

#if defined _adt_stack_included

 #endinput

#endif

#define _adt_stack_included

/**

 * Creates a stack structure.  A stack is a LIFO (last in, first out) 

 * vector (array) of items.  It has O(1) insertion and O(1) removal.

 *

 * Stacks have two operations: Push (adding an item) and Pop (removes 

 * items in reverse-push order).

 * 

 * The contents of the stack are uniform; i.e. storing a string and then 

 * retrieving it as an integer is NOT the same as StringToInt()!

 *

 * The "blocksize" determines how many cells each slot has; it cannot

 * be changed after creation.

 *

 * @param blocksize		The number of cells each entry in the stack can 

 *						hold.  For example, 32 cells is equivalent to:

 *						new Array[X][32]

 * @return				New stack Handle.

 */

native Handle:CreateStack(blocksize=1);

/**

 * Pushes a value onto the end of the stack, adding a new index.

 *

 * This may safely be used even if the stack has a blocksize

 * greater than 1.

 *

 * @param stack			Stack Handle.

 * @param value			Value to push.

 * @noreturn

 * @error				Invalid Handle or out of memory.

 */

native PushStackCell(Handle:stack, any:value);

/**

 * Pushes a string onto the end of a stack, truncating it if it is 

 * too big.

 *

 * @param stack			Stack Handle.

 * @param value			String to push.

 * @noreturn

 * @error				Invalid Handle or out of memory.

 */

native PushStackString(Handle:stack, const String:value[]);

/**

 * Pushes an array of cells onto the end of a stack.  The cells

 * are pushed as a block (i.e. the entire array takes up one stack slot),

 * rather than pushing each cell individually.

 *

 * @param stack			Stack Handle.

 * @param values		Block of values to copy.

 * @param size			If not set, the number of elements copied from the array

 *						will be equal to the blocksize.  If set higher than the 

 *						blocksize, the operation will be truncated.

 * @noreturn

 * @error				Invalid Handle or out of memory.

 */

native PushStackArray(Handle:stack, const any:values[], size=-1);

/**

 * Pops a cell value from a stack.

 *

 * @param stack			Stack Handle.

 * @param value			Variable to store the value.

 * @param block			Optionally specify which block to read from

 *						(useful if the blocksize > 0).

 * @param asChar		Optionally read as a byte instead of a cell.

 * @return				True on success, false if the stack is empty.

 * @error				Invalid Handle.

 */

native bool:PopStackCell(Handle:stack, &any:value, block=0, bool:asChar=false);

/**

 * Pops a string value from a stack.

 *

 * @param stack			Stack Handle.

 * @param buffer		Buffer to store string.

 * @param maxlength		Maximum size of the buffer.

 * @return				True on success, false if the stack is empty.

 * @error				Invalid Handle.

 */

native bool:PopStackString(Handle:stack, String:buffer[], maxlength, &written=0);

/**

 * Pops an array of cells from a stack.

 *

 * @param stack			Stack Handle.

 * @param buffer		Buffer to store the array in.

 * @param size			If not set, assumes the buffer size is equal to the

 *						blocksize.  Otherwise, the size passed is used.

 * @return				True on success, false if the stack is empty.

 * @error				Invalid Handle.

 */

native bool:PopStackArray(Handle:stack, any:buffer[], size=-1);

/**

 * Checks if a stack is empty.

 *

 * @param stack			Stack Handle.

 * @return				True if empty, false if not empty.

 * @error				Invalid Handle.

 */

native bool:IsStackEmpty(Handle:stack);

/**

 * Pops a value off a stack, ignoring it completely.

 *

 * @param stack			Stack Handle.

 * @return				True if something was popped, false otherwise.

 * @error				Invalid Handle.

 */

stock PopStack(Handle:stack)

{

	new value;

	return PopStackCell(stack, value);

}