code: public final int strNCmp(byte[]bytes, int p, int end, byte[]ascii, int asciiP, int n) {
          while (n-- > 0) {
              if (p >= end) return ascii[asciiP];
              int c = mbcToCode(bytes, p, end);
              int x = ascii[asciiP] - c;
              if (x != 0) return x;
  
              asciiP++;
              p += length(bytes, p, end);
          }
          return 0;
      }
docs: /* onigenc_with_ascii_strncmp