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tetex-bin  3.0
fifo_defs.h
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00001 /****************************************************************************
00002  * Copyright (c) 1998,2002 Free Software Foundation, Inc.                   *
00003  *                                                                          *
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00005  * copy of this software and associated documentation files (the            *
00006  * "Software"), to deal in the Software without restriction, including      *
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00009  * copies of the Software, and to permit persons to whom the Software is    *
00010  * furnished to do so, subject to the following conditions:                 *
00011  *                                                                          *
00012  * The above copyright notice and this permission notice shall be included  *
00013  * in all copies or substantial portions of the Software.                   *
00014  *                                                                          *
00015  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
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00020  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
00021  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
00022  *                                                                          *
00023  * Except as contained in this notice, the name(s) of the above copyright   *
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00028 
00029 /****************************************************************************
00030  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
00031  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
00032  ****************************************************************************/
00033 
00034 /*
00035  * Common macros for lib_getch.c, lib_ungetch.c
00036  *
00037  * $Id: fifo_defs.h,v 1.4 2002/03/16 20:47:50 tom Exp $
00038  */
00039 
00040 #ifndef FIFO_DEFS_H
00041 #define FIFO_DEFS_H 1
00042 
00043 #define head  SP->_fifohead
00044 #define tail  SP->_fifotail
00045 /* peek points to next uninterpreted character */
00046 #define peek  SP->_fifopeek
00047 
00048 #define h_inc() { head == FIFO_SIZE-1 ? head = 0 : head++; if (head == tail) head = -1, tail = 0;}
00049 #define h_dec() { head == 0 ? head = FIFO_SIZE-1 : head--; if (head == tail) tail = -1;}
00050 #define t_inc() { tail == FIFO_SIZE-1 ? tail = 0 : tail++; if (tail == head) tail = -1;}
00051 #define t_dec() { tail == 0 ? tail = FIFO_SIZE-1 : tail--; if (head == tail) fifo_clear();}
00052 #define p_inc() { peek == FIFO_SIZE-1 ? peek = 0 : peek++;}
00053 
00054 #define cooked_key_in_fifo()       ((head != -1) && (peek != head))
00055 #define raw_key_in_fifo()   ((head != -1) && (peek != tail))
00056 
00057 #undef HIDE_EINTR
00058 
00059 #endif /* FIFO_DEFS_H */