private Expression visit0()

in src/main/java/net/hydromatic/linq4j/expressions/OptimizeVisitor.java [218:268]

45 lines of code
17 McCabe index (conditional complexity)


  private Expression visit0(
      BinaryExpression binary,
      Expression expression0,
      Expression expression1) {
    Boolean always;
    switch (binary.getNodeType()) {
    case AndAlso:
      always = always(expression0);
      if (always != null) {
        return always
            ? expression1
            : FALSE_EXPR;
      }
      break;
    case OrElse:
      always = always(expression0);
      if (always != null) {
        // true or x  --> true
        // false or x --> x
        return always
            ? TRUE_EXPR
            : expression1;
      }
      break;
    case Equal:
      if (isConstantNull(expression1)
          && Primitive.is(expression0.getType())) {
        return FALSE_EXPR;
      }
      // a == true  -> a
      // a == false -> !a
      always = always(expression0);
      if (always != null) {
        return always ? expression1 : Expressions.not(expression1);
      }
      break;
    case NotEqual:
      if (isConstantNull(expression1)
          && Primitive.is(expression0.getType())) {
        return TRUE_EXPR;
      }
      // a != true  -> !a
      // a != false -> a
      always = always(expression0);
      if (always != null) {
        return always ? Expressions.not(expression1) : expression1;
      }
      break;
    }
    return null;
  }