96   lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len);  in utflen()  local
99   luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 2,  in utflen()
103   while (posi <= posj) {  in utflen()
104     const char *s1 = utf8_decode(s + posi, NULL, !lax);  in utflen()
107       lua_pushinteger(L, posi + 1);  /* ... and current position */  in utflen()
110     posi = s1 - s;  in utflen()
125   lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len);  in codepoint()  local
126   lua_Integer pose = u_posrelat(luaL_optinteger(L, 3, posi), len);  in codepoint()
130   luaL_argcheck(L, posi >= 1, 2, "out of bounds");  in codepoint()
132   if (posi > pose) return 0;  /* empty interval; return no values */  in codepoint()
133   if (pose - posi >= INT_MAX)  /* (lua_Integer -> int) overflow? */  in codepoint()
135   n = (int)(pose -  posi) + 1;  /* upper bound for number of returns */  in codepoint()
139   for (s += posi - 1; s < se;) {  in codepoint()
187   lua_Integer posi = (n >= 0) ? 1 : len + 1;  in byteoffset()  local
188   posi = u_posrelat(luaL_optinteger(L, 3, posi), len);  in byteoffset()
189   luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 3,  in byteoffset()
193     while (posi > 0 && iscont(s + posi)) posi--;  in byteoffset()
196     if (iscont(s + posi))  in byteoffset()
199        while (n < 0 && posi > 0) {  /* move back */  in byteoffset()
201            posi--;  in byteoffset()
202          } while (posi > 0 && iscont(s + posi));  in byteoffset()
208        while (n > 0 && posi < (lua_Integer)len) {  in byteoffset()
210            posi++;  in byteoffset()
211          } while (iscont(s + posi));  /* (cannot pass final '\0') */  in byteoffset()
217     lua_pushinteger(L, posi + 1);  in byteoffset()