map.c

   1 /* mapping register/macro names to indices */
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include "roff.h"
   5
   6 #define MAPBEG          256     /* the entries reserved for .x names */
   7
   8 /* register, macro, or environments names */
   9 static struct dict mapdict;
  10 static int mapinit;
  11
  12 /* map register names to [0..NREGS] */
  13 int map(char *s)
  14 {
  15         int i;
  16         if (s[0] == '.' && s[1] && !s[2])       /* ".x" is mapped to 'x' */
  17                 return (unsigned char) s[1];
  18         if (!mapinit) {
  19                 dict_init(&mapdict, NREGS, -1, 1, 1);
  20                 mapinit = 1;
  21         }
  22         i = dict_idx(&mapdict, s);
  23         if (i < 0) {
  24                 dict_put(&mapdict, s, 0);
  25                 i = dict_idx(&mapdict, s);
  26         }
  27         return MAPBEG + i;
  28 }
  29
  30 /* return the name mapped to id; returns a static buffer */
  31 char *map_name(int id)
  32 {
  33         static char map_buf[NMLEN];
  34         if (id >= MAPBEG)
  35                 return dict_key(&mapdict, id - MAPBEG);
  36         map_buf[0] = '.';
  37         map_buf[1] = id;
  38         map_buf[2] = '\0';
  39         return map_buf;
  40 }