Package net.sourceforge.pmd.lang.java.rule.codestyle

Class ConfusingTernaryRule

  • All Implemented Interfaces:
    AstVisitor, JavaVisitor, Rule, PropertySource
    public class ConfusingTernaryRule
extends AbstractJavaRulechainRule
    if (x != y) { diff(); } else { same(); } and
    (!x ? diff() : same());

    XPath can handle the easy cases, e.g.:

        //IfStatement[
      Statement[2]
      and Expression[
        EqualityExpression[@Image="!="] or
        UnaryExpressionNotPlusMinus[@Image="!"]]]

    But "&&" and "||" are difficult, since we need a match for all children instead of just one. This can be done by using a double-negative, e.g.:

        not(*[not(matchme)])

    Still, XPath is unable to handle arbitrarily nested cases, since it lacks recursion, e.g.:

     if (((x != !y)) || !(x)) {
     diff();
 } else {
     same();
 }