commands/cawf/expr.c

   1 /*
   2  *      expr.c - expression support functions for cawf(1)
   3  */
   4
   5 /*
   6  *      Copyright (c) 1991 Purdue University Research Foundation,
   7  *      West Lafayette, Indiana 47907.  All rights reserved.
   8  *
   9  *      Written by Victor A. Abell <abe@mace.cc.purdue.edu>,  Purdue
  10  *      University Computing Center.  Not derived from licensed software;
  11  *      derived from awf(1) by Henry Spencer of the University of Toronto.
  12  *
  13  *      Permission is granted to anyone to use this software for any
  14  *      purpose on any computer system, and to alter it and redistribute
  15  *      it freely, subject to the following restrictions:
  16  *
  17  *      1. The author is not responsible for any consequences of use of
  18  *         this software, even if they arise from flaws in it.
  19  *
  20  *      2. The origin of this software must not be misrepresented, either
  21  *         by explicit claim or by omission.  Credits must appear in the
  22  *         documentation.
  23  *
  24  *      3. Altered versions must be plainly marked as such, and must not
  25  *         be misrepresented as being the original software.  Credits must
  26  *         appear in the documentation.
  27  *
  28  *      4. This notice may not be removed or altered.
  29  */
  30
  31 #include "cawf.h"
  32
  33
  34 /*
  35  * Asmcode(s, c) - assemble number/name code following backslash-character
  36  *                 definition  - e. .g, "\\nPO"
  37  */
  38
  39 unsigned char *
  40 Asmcode(s, c)
  41         unsigned char **s;              /* pointer to character after '\\' */
  42         unsigned char *c;               /* code destination (c[3]) */
  43 {
  44         unsigned char *s1;
  45
  46         s1 = *s + 1;
  47         c[0] = c[1] = c[2] = '\0';
  48         if ((c[0] = *s1) == '(') {
  49                 s1++;
  50                 if ((c[0] = *s1) != '\0') {
  51                         s1++;
  52                         c[1] = *s1;
  53                 }
  54         }
  55         return(s1);
  56 }
  57
  58
  59 /*
  60  * Delnum(nx) - delete number
  61  */
  62
  63 void
  64 Delnum(nx)
  65         int nx;                         /* number index */
  66 {
  67         unsigned char buf[MAXLINE];     /* message buffer */
  68
  69         if (nx >= Nnr) {
  70                 (void) sprintf((char *)buf, " bad Delnum(%d) index", nx);
  71                 Error(FATAL, LINE, (char *)buf, NULL);
  72         }
  73         while (nx < (Nnr - 1)) {
  74                 Numb[nx] = Numb[nx + 1];
  75                 nx++;
  76         }
  77         Nnr--;
  78 }
  79
  80
  81 /*
  82  * Findnum(n, v, e) - find or optionally enter number value
  83  */
  84
  85 Findnum(n, v, e)
  86         unsigned char *n;               /* register name */
  87         int v;                          /* value */
  88         int e;                          /* 0 = find, don't enter
  89                                          * 1 = enter, don't find */
  90 {
  91         int cmp, low, hi, mid;          /* binary search controls */
  92         unsigned char c[3];             /* name buffer */
  93
  94         c[0] = n[0];
  95         c[1] = (n[1] == ' ' || n[1] == '\t') ? '\0' : n[1];
  96         c[2] = '\0';
  97         low = mid = 0;
  98         hi = Nnr - 1;
  99         while (low <= hi) {
 100                 mid = (low + hi) / 2;
 101                 if ((cmp = strncmp((char *)c, (char *)Numb[mid].nm, 2)) < 0)
 102                         hi = mid - 1;
 103                 else if (cmp > 0)
 104                         low = mid + 1;
 105                 else {
 106                         if (e)
 107                                 Numb[mid].val = v;
 108                         return(mid);
 109                 }
 110         }
 111         if ( ! e)
 112                 return(-1);
 113         if (Nnr >= MAXNR)
 114                 Error(FATAL, LINE, " out of number registers at ", (char *)c);
 115         if (Nnr) {
 116                 if (cmp > 0)
 117                         mid++;
 118                 for (hi = Nnr - 1; hi >= mid; hi--)
 119                         Numb[hi+1] = Numb[hi];
 120         }
 121         Nnr++;
 122         Numb[mid].nm[0] = c[0];
 123         Numb[mid].nm[1] = c[1];
 124         Numb[mid].val = v;
 125         return(mid);
 126 }
 127
 128
 129 /*
 130  * Findparms(n) - find parameter registers
 131  */
 132
 133 Findparms(n)
 134         unsigned char *n;               /* parameter name */
 135 {
 136         unsigned char c[3];             /* character buffer */
 137         int i;                          /* temporary index */
 138
 139         c[0] = n[0];
 140         c[1] = (n[1] == ' ' || n[1] == '\t') ? '\0' : n[1];
 141         c[2] = '\0';
 142         for (i = 0; Parms[i].nm[0]; i++) {
 143                 if (c[0] == Parms[i].nm[0] && c[1] == Parms[i].nm[1])
 144                         return(i);
 145         }
 146         return(-1);
 147 }
 148
 149
 150 /*
 151  * Findscale(n, v, e) - find and optionally enter scaling factor value
 152  */
 153
 154 Findscale(n, v, e)
 155         int n;                          /* scaling factor name */
 156         double v;                       /* value */
 157         int e;                          /* 0 = find, don't enter
 158                                          * 1 = enter, don't find */
 159 {
 160         int i;
 161         double *pval;
 162
 163         for (i = 0; Scale[i].nm; i++) {
 164                 if ((unsigned char )n == Scale[i].nm)
 165                         break;
 166         }
 167         if (Scale[i].nm) {
 168                 if (e) {
 169                         pval = &Scale[i].val;
 170                         *pval = v;
 171                 }
 172                 return(i);
 173         }
 174         return(-1);
 175 }