Method empty

java/com/google/re2j/Compiler.java:168–173

(int op)

  // op is a bitmask of EMPTY_* flags.
  private Frag empty(int op) {
    Frag f = newInst(Inst.EMPTY_WIDTH);
    prog.getInst(f.i).arg = op;
    f.out = f.i << 1;
    return f;
  }

  private Frag rune(int rune, int flags) {
    return rune(new int[] {rune}, flags);