src/Q.h

   1 /*
   2  * Q.h -  support for ForAll, ThereExists, Count and Sum (i.e. quantifiers).
   3  *
   4  * Portability: this file uses the GNU C Statement Expression extension and
   5  *    so requires GCC/C++ with extensions enabled (this is checked by the
   6  *    header file).
   7  *
   8  * Copyright (c) 1997 Phil Maker
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * Id: Q.h,v 1.1.1.1 1997/11/23 11:45:50 pjm Exp
  33  */
  34
  35
  36 #ifndef _Q_h_
  37 #define _Q_h_ 1
  38
  39 #ifdef __cplusplus
  40 extern "C" {
  41 #endif
  42
  43 #ifndef WITHOUT_NANA
  44
  45 #ifndef __GNUC__ /* not compiling with GCC/G++ extensions */
  46 error
  47 This file requires the GNU C/C++ "statement expression" extension;
  48 so use GCC/G++ with extensions enabled. If you have not got GCC then
  49 misery follows though we may be able to do something about it
  50 in the future.
  51 #endif
  52
  53 /*
  54  * A(i,c,n,a) - true iff a is true for all values generated by for(i;c;n)
  55  *
  56  * Note: local variables can be introduced in this statement even in C.
  57  */
  58
  59 #define A(i,c,n,a) /* ForAll */ \
  60         ({ \
  61                 int _A_result = 1; \
  62                 i; \
  63                 while(c) { \
  64                         if(!(a)) { \
  65                                 _A_result = 0; \
  66                                 break; \
  67                         } \
  68                         n; \
  69                 } \
  70                 _A_result; \
  71         })
  72
  73 /*
  74  * E(i,c,n,a) - true iff exists any true a for values generated by for(i;c;n)
  75  */
  76
  77 #define E(i,c,n,a) /* Exists */ \
  78         ({ \
  79                 int _E_result = 0; \
  80                 i; \
  81                 while(c) { \
  82                         if(a) { \
  83                                 _E_result = 1; \
  84                                 break; \
  85                         } \
  86                         n; \
  87                 } \
  88                 _E_result; \
  89         })
  90
  91 /*
  92  * C(i,c,n,a) - count the number of times a is true over the values
  93  * generated by for(i;c;n)
  94  */
  95
  96 #define C(i,c,n,a) /* Count */ \
  97         ({ \
  98                 long _C_result = 0; \
  99                 i; \
 100                 while(c) { \
 101                         if(a) { \
 102                                 _C_result++; \
 103                         } \
 104                         n; \
 105                 } \
 106                 _C_result; \
 107         })
 108
 109 /*
 110  * E1(i,c,n,a) - exists a single value generated by for(i;c;n)
 111  * suchthat i is true.
 112  */
 113
 114 #define E1(i,c,n,a) (C(i,c,n,a) == 1) /* There Exists 1 */
 115
 116 /*
 117  * S(i,c,n,v) - sum of v over the values generated by for(i;c;n)
 118  */
 119
 120 #define S(i,c,n,v) \
 121         ({ \
 122                 i; \
 123                 typeof(v) _S_result = 0; \
 124                 while(c) { \
 125                         _S_result += (v); \
 126                         n; \
 127                 } \
 128                 _S_result; \
 129         })
 130
 131 /*
 132  * P(i,c,n,v) - product of v over the values generated by for(i;c;n)
 133  */
 134
 135 #define P(i,c,n,v) \
 136         ({ \
 137                 i; \
 138                 typeof(v) _P_result = 1; \
 139                 while(c) { \
 140                         _P_result *= (v); \
 141                         n; \
 142                 } \
 143                 _P_result; \
 144         })
 145
 146 #else /* defined(WITHOUT_NANA) */
 147
 148 /*
 149  * we don't produce any empty stubs for Q.h when compiling without nana
 150  * since calls to A(...), etc should only occur in stubbed out code such
 151  * as I(...).
 152  */
 153
 154 #endif /* !defined(WITHOUT_NANA) */
 155 #ifdef __cplusplus
 156 }
 157 #endif
 158
 159 #endif /* _Q_h_ */
 160