public final RegExp resolveTilde()

in jflex/src/main/java/jflex/core/RegExp.java [168:227]
47 lines of code
13 McCabe index (conditional complexity)

  public final RegExp resolveTilde() {
    RegExp1 unary;
    RegExp2 binary;
    RegExp content;

    switch (type) {
      case sym.BAR:
        binary = (RegExp2) this;
        return new RegExp2(sym.BAR, binary.r1.resolveTilde(), binary.r2.resolveTilde());

      case sym.CONCAT:
        binary = (RegExp2) this;
        return new RegExp2(sym.CONCAT, binary.r1.resolveTilde(), binary.r2.resolveTilde());

      case sym.STAR:
        unary = (RegExp1) this;
        content = (RegExp) unary.content;
        return new RegExp1(sym.STAR, content.resolveTilde());

      case sym.PLUS:
        unary = (RegExp1) this;
        content = (RegExp) unary.content;
        return new RegExp1(sym.PLUS, content.resolveTilde());

      case sym.QUESTION:
        unary = (RegExp1) this;
        content = (RegExp) unary.content;
        return new RegExp1(sym.QUESTION, content.resolveTilde());

      case sym.BANG:
        unary = (RegExp1) this;
        content = (RegExp) unary.content;
        return new RegExp1(sym.BANG, content.resolveTilde());

      case sym.TILDE:
        // ~a = !([^]* a [^]*) a
        // uses subexpression sharing
        unary = (RegExp1) this;
        content = ((RegExp) unary.content).resolveTilde();

        RegExp any_star = new RegExp1(sym.STAR, anyChar());
        RegExp neg =
            new RegExp1(
                sym.BANG,
                new RegExp2(sym.CONCAT, any_star, new RegExp2(sym.CONCAT, content, any_star)));

        return new RegExp2(sym.CONCAT, neg, content);

      case sym.STRING:
      case sym.STRING_I:
      case sym.CHAR:
      case sym.CHAR_I:
      case sym.PRIMCLASS:
        unary = (RegExp1) this;
        return new RegExp1(unary.type, unary.content);

      default:
        throw new RegExpException(this);
    }
  }