ComplexComparison.java

import java.util.Comparator;
import org.checkerframework.checker.interning.qual.Interned;

public class ComplexComparison {

    void testInterned() {

        @Interned String a = "foo";
        @Interned String b = "bar";

        if (a != null && b != null && a == b) {
            System.out.println("yes");
        } else {
            System.out.println("no");
        }
    }

    void testInternedDueToFlow() {

        String c = "foo";
        String d = "bar";

        if (c != null && d != null && c == d) {
            System.out.println("yes");
        } else {
            System.out.println("no");
        }
    }

    void testNotInterned() {

        String e = new String("foo");
        String f = new String("bar");

        //:: error: (not.interned)
        if (e != null && f != null && e == f) {
            System.out.println("yes");
        } else {
            System.out.println("no");
        }
    }

    /* @ pure */ public class DoubleArrayComparatorLexical implements Comparator<double[]> {

        /**
         * Lexically compares o1 and o2 as double arrays.
         *
         * @return positive if o1 > 02, 0 if 01 == 02, negative if 01 < 02
         */
        public int compare(double[] a1, double[] a2) {
            // Heuristic: permit "arg1 == arg2" in a test in the first statement
            // of a "Comparator.compare" method, if the body just returns 0.
            if (a1 == a2) {
                return 0;
            }
            int len = Math.min(a1.length, a2.length);
            for (int i = 0; i < len; i++) {
                if (a1[i] != a2[i]) {
                    return ((a1[i] > a2[i]) ? 1 : -1);
                }
            }
            return a1.length - a2.length;
        }
    }

    class C {
        @Override
        @org.checkerframework.dataflow.qual.Pure
        public boolean equals(Object other) {
            // Heuristic: permit "this == arg1" in a test in the first statement
            // of a "Comparator.compare" method, if the body just returns true.
            if (this == other) {
                return true;
            }
            return super.equals(other);
        }
    }

    // // TODO
    // class D {
    //     @Override
    //     public boolean equals(Object other) {
    //         // Don't suppress warnings at "this == arg1" if arg1 has been reassigned
    //         other = new Object();
    //
    //         if (this == other) {
    //             return true;
    //         }
    //         return super.equals(other);
    //     }
    // }

}