lily/keyword.cc

   1 /*
   2   keyword.cc -- keywords and identifiers
   3  */
   4 #include <string.h>
   5 #include <stdlib.h>
   6 #include "keyword.hh"
   7
   8
   9 /* for qsort */
  10 int
  11       tabcmp (void const * p1, void const * p2)
  12 {
  13   return strcmp (( (Keyword_ent const *) p1)->name,
  14  ((Keyword_ent const *) p2)->name);
  15 }
  16
  17 Keyword_table::Keyword_table (Keyword_ent *tab)
  18 {
  19   table = tab;
  20
  21   /* count keywords */
  22   for (maxkey = 0; table[maxkey].name; maxkey++)
  23     ;
  24
  25   /* sort them */
  26   qsort (table, maxkey, sizeof (Keyword_ent), tabcmp);
  27 }
  28
  29 /*
  30   lookup with binsearch, return tokencode.
  31 */
  32 int
  33 Keyword_table::lookup (char const *s) const
  34 {
  35   int lo;
  36   int hi;
  37   int cmp;
  38   int result;
  39   lo = 0;
  40   hi = maxkey;
  41
  42   /* binary search */
  43   do
  44   {
  45       cmp = (lo + hi) / 2;
  46
  47       result = strcmp (s, table[cmp].name);
  48
  49       if (result < 0)
  50           hi = cmp;
  51       else
  52           lo = cmp;
  53     }
  54   while (hi - lo > 1);
  55   if (!strcmp (s, table[lo].name))
  56   {
  57       return table[lo].tokcode;
  58     }
  59   else
  60       return -1;              /* not found */
  61 }
  62