--- src/interpret.c	Fri Nov 12 02:05:32 1999
+++ src-stick/interpret.c	Fri Nov 12 17:25:20 1999
@@ -16552,6 +16552,142 @@
     }
 #endif /* F_SET_LIGHT */
 
+#ifdef F_SUBSTITUTE_STRING
+ /* Added to support StickLib: */
+     CASE(F_SUBSTITUTE_STRING);
+     {
+#define	MAX_REC_DEPTH	8
+#define STR_BUF_LENGTH	4096
+#define	MY_ALNUM(x)	(isalnum(x) || x == '_')
+
+       static char *rec_stack[MAX_REC_DEPTH];
+       static char strbuf[STR_BUF_LENGTH + 1];
+       svalue_t *arg;
+       char *ret, *src;
+       vector_t *aliases, *repl_strings;
+       int min_len, max_len;
+       int a_size;
+       int rec_count = 0, replaced = 0;
+       char *dest = strbuf;
+       char *end = &strbuf[STR_BUF_LENGTH - 1];
+       char *a, *b, *tmp;
+       char x;
+       int i, str_len, low, high, curr, bingo;
+
+       arg = sp - 4;
+       if (arg[0].type != T_STRING)
+	 goto bad_arg_1;
+       if (arg[1].type != T_POINTER)
+	 goto bad_arg_2;
+       if (arg[2].type != T_POINTER)
+	 goto bad_arg_3;
+       if (arg[3].type != T_NUMBER)
+	 goto bad_arg_4;
+       if (arg[4].type != T_NUMBER)
+	 goto bad_arg_4;
+       /* Hmmh, last is incorrect of course but I don't want to
+	* add a new label to the other place. :-)
+	*/
+
+       src = arg[0].u.string;
+       aliases = arg[1].u.vec;
+       repl_strings = arg[2].u.vec;
+       min_len = arg[3].u.number;
+       max_len = arg[4].u.number;
+       a_size = VEC_SIZE(aliases);
+
+       /* The core substitute_string() code: */
+
+       do { /* Main substitute_string loop... */
+
+	 /* First we'll skip through the separators (non-letters) */
+	 while ((x = *src) && !(MY_ALNUM(x))) {
+	   /* Let's skip all non-letters */
+	   *dest = x;
+	   if (++dest >= end) {
+	     ret = replaced ? (*dest = '\0', strbuf) : NULL;
+	     goto subst_string_done;
+	   }
+	   src++;
+	 }
+
+	 /* If we ran to the end of the string we'll 'return from
+	  * recursions', or, if at the top level, end substitution:
+	  */
+	 if (!x) {
+	   if (!rec_count) {
+	     ret = replaced ? (*dest = '\0', strbuf) : NULL;
+ 	     goto subst_string_done;
+	   }
+	   src = rec_stack[--rec_count];
+	   continue;
+	 }
+	 tmp = src;
+	 while ((x = *tmp) && MY_ALNUM(x))
+	   tmp++;	/* Let's search last char of the word. */
+	 str_len = tmp - src;
+	 if (str_len >= min_len && str_len <= max_len &&
+	     rec_count < MAX_REC_DEPTH) {
+	   bingo = low = -1;
+	   high = a_size;
+	   while ((curr = (low + high) / 2) > low) {
+	     a = src;
+	     b = aliases -> item[curr].u.string;
+	     i = 1;
+	     while ((x = *b) && !(i = *a - x)) {
+	       a++;
+	       b++;
+	     }
+	     if (!i && a == tmp) {
+	       bingo = curr;
+	       break;
+	     }
+	     if (i < 0) {
+	       if (!curr) break;
+	       high = curr;
+	     } else {
+	       low = curr;
+	     }
+	   }
+	   if (bingo >= 0) {
+	     rec_stack[rec_count++] = tmp;
+	     src = repl_strings -> item[bingo].u.string;
+	     replaced++;
+	     continue;
+	   }
+	 }
+	 if (str_len > (end - dest + 1)) {
+	   while (dest < end) {
+	     *dest = *src;
+	     dest++;
+	     src++;
+	   }
+	   ret = replaced ? (*dest = '\0', strbuf) : NULL;
+	   goto subst_string_done;
+	 }
+	 do {
+	   *dest = *src;
+	   dest++;
+	 } while (++src < tmp);
+       } while (1);
+
+     subst_string_done:
+
+/*********/
+
+       if (!ret) {
+	 pop_n_elems(4);
+       } else {
+	 pop_n_elems(5);
+fprintf(stderr, "Result = %s.\n", ret);
+	 push_string_malloced(ret);
+       }
+       break;
+     }
+
+ /* ... end of StickLib-extra-func */
+#endif
+
     /* --- XEfun and XCodes --- */
 
     CASE(F_ESCAPE);                  /* --- escape <instr> ... --- */