Comments on: Java Trivia

By: λ Tony’s blog λ » Blog Archive » Optional -> a (negative proof)

λ Tony’s blog λ » Blog Archive » Optional -> a (negative proof) — Sun, 20 Jun 2010 03:57:20 +0000

[...] λ Tony’s blog λ The weblog of Tony Morris « Java Trivia [...]

By: Berlin Brown

Berlin Brown — Sat, 12 Jun 2010 06:11:32 +0000

Also, keep the Java posts coming for those of us that haven’t completely moved to Scala.

By: Berlin Brown

Berlin Brown — Sat, 12 Jun 2010 05:32:20 +0000

I don’t know why I found this so interesting but I did and wrote a verbose impl.

So, like Bas, use anony innner-class impl. I didn’t see that immediately

https://doingitwrongnotebook.googlecode.com/svn/trunk/doingitwrong_phase1/src/java/src/org/berlin/tonyblog/Trivia1.java

Here is an example test case, don’t know if that is the intended purpose or not.

public static void test2() {
System.out.println(”Trivia 2 - return Function“);
final Function[Integer, Integer] f_ab = new Function[Integer, Integer]() {

@Override
public Integer apply(Integer a) {
return a * 2;
}
}; // End of Anon a-b

final Function[Integer, Integer] g_bc = new Function[Integer, Integer]() {
@Override
public Integer apply(Integer b) {
return b * 3;
}
}; // End of Anon a-b

System.out.println(”Result: ” + c(f_ab, g_bc).apply(10));
}

—-

Output is 60.

By: Tony Morris

Tony Morris — Fri, 11 Jun 2010 10:52:44 +0000

Yes, this is true Ricky. I had clarified the rules. Sorry for the confusion.

By: Ricky Clarkson

Ricky Clarkson — Thu, 10 Jun 2010 20:24:58 +0000

No, type-casting *is* disallowed in the rules, but wasn’t at the time I wrote my comment.

By: Tom

Tom — Thu, 10 Jun 2010 07:01:20 +0000

Ricky: casting was disallowed in the rules

By: Ricky Clarkson

Ricky Clarkson — Fri, 04 Jun 2010 09:58:44 +0000

In case it’s not obvious, I’d just like to point out that my answer was a joke, though a joke that will compile and will sometimes work at runtime. It gives a compile warning.

By: Jim

Jim — Wed, 02 Jun 2010 13:52:53 +0000

Am I missing something?

I feel I must be, b/c while I still haven’t been able to work myself through ‘Beginner Java Exercise with Data Types’ in 20 minutes, it took me about 10 seconds to independently come up with the solution Andrey posted above.

By: Ionut G. Stan

Ionut G. Stan — Wed, 02 Jun 2010 08:26:47 +0000

Is there any reason for which my answer doesn’t get moderated?

By: Andrey Vityuk

Andrey Vityuk — Wed, 02 Jun 2010 06:56:48 +0000

Sorry, generics escaped…
return new Function() {
   public C apply(A a) {
      return g.apply(f.apply(a));
   }
};