A couple of Bugs

[Ali Ebrahimi]

Hi Maurizio,
I discovered a few bugs in current compiler, some of them not lambda
specific.
This is test case.

public class Test {

    static class Array<A> {
        private A[] data;

        Array(A[] data) {
            this.data = data;
        }

        public static <A> Array<A> array(final A... a) {
            return new Array<A>(a);
        }

        public A[] array() {
            return null;
        }

         public boolean forAll(final F<A, Boolean> f) {
            for (final A x : data)
                if (f.f(x))
                    return true;

            return false;
        }

    }

    public interface F<A, B> {
        B f(A a);
    }

    public static <A> Array<A> test() {
        return Array.<A>array();
    }

    public static Array<Character> fromString(final String s) {
        List<Character> cs = Collections.emptyList();

        for (int i = s.length() - 1; i >= 0; i--)
            cs.add(s.charAt(i));

        return new Array<Character>(cs.toArray(new Character[0]));
    }

    public static void main(String[] args) {

        final Array<String> a = Array.array("Hello", "There", "what", "DAY",
"iS", "iT");
        final boolean b = a.forAll(#{String s -> fromString(s).forAll(#{
Character c ->  isLowerCase(c)}) }); //***********
        System.out.println(b); // true ("what" provides the only example;
try removing it)
    }
}

Result:

Information:Note: Recompile with -Xlint:unchecked for details.
Information:Compilation completed with 3 errors and 1 warning
Information:3 errors
Information:1 warning
F:\ali\projects\java6\src\Test.java
    Error:Error:line (46)error: non-static method array() cannot be
referenced from a static context
where A is a type-variable:
A extends Object declared in class Array
    Error:Error:line (46)error: incompatible types
required: Array<A>
found:    Object[]
where A is a type-variable:
A extends Object declared in method <A>test()
    Error:Error:line (61)error: method forAll in class Array<A> cannot be
applied to given types;
required: F<String,Boolean>
found: <lambda>
reason: actual argument <lambda> cannot be converted to F<String,Boolean> by
method invocation conversion
(incompatible return type ?boolean in lambda expression)
where A is a type-variable:
A extends Object declared in class Array
    Warning:Warning:Note: F:\ali\projects\java6\src\Test.java uses unchecked
or unsafe operations.


Othar than last case, all compiles with jdk6. This case relates to
boxing-unboxing primitive types in return types.
If I add explicit cast in return type, it compiles:
  final boolean b = a.forAll(#{String s -> (Boolean)fromString(s).forall(#{
Character c ->  isLowerCase(c)}) });


Best Regards,
Ali Ebrahimi