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
  11 /* map register names to [0..NREGS] */
  12 int map(char *s)
  13 {
  14         int i;
  15         if (s[0] == '.' && s[1] && !s[2])       /* ".x" is mapped to 'x' */
  16                 return (unsigned char) s[1];
  17         if (!mapdict)
  18                 mapdict = dict_make(-1, 1, 1);
  19         i = dict_idx(mapdict, s);
  20         if (i < 0) {
  21                 dict_put(mapdict, s, 0);
  22                 i = dict_idx(mapdict, s);
  23         }
  24         return MAPBEG + i;
  25 }
  26
  27 /* return the name mapped to id; returns a static buffer */
  28 char *map_name(int id)
  29 {
  30         static char map_buf[NMLEN];
  31         if (id >= MAPBEG)
  32                 return dict_key(mapdict, id - MAPBEG);
  33         map_buf[0] = '.';
  34         map_buf[1] = id;
  35         map_buf[2] = '\0';
  36         return map_buf;
  37 }
  38
  39 void map_done(void)
  40 {
  41         if (mapdict)
  42                 dict_free(mapdict);
  43 }