I'll just note that @FunctionalInterface is not *required* to convert a
lambda to the target type; it is a statement of *design intent* by the
interface author (which comes with some compile-time enforcement) that
the interface is intended to be used to specify a function-like thing.
On 2/6/2013 2:43 PM, Joe Darcy wrote:
Hi Sean,
Apart from the performance concern Brian has already raised, I think the
basic question to provide guidance on whether or not
@FunctionalInterfaces should be applied to existing types is: do people
routinely use anonymous inner classes to create instances of these types
today? If so, the @FunctionalInterface annotation should be added to
indicate the type is meant to be used for lambda expressions too.
The JSR for lambda has some specification material and there is a lambda
faq in progress (http://www.lambdafaq.org/), but I'm not aware of any
existing discussion of the use of @FunctionalInterface since it is a
relatively new addition to JDK 8 builds.
HTH,
-Joe
On 2/6/2013 11:34 AM, Sean Mullan wrote:
I need to come up to speed on lambda in order to properly review this.
What's the best place to learn more about lambda and
FunctionalInterfaces?
Thanks,
Sean
On 02/05/2013 05:35 PM, Joe Darcy wrote:
Hello,
As part of Project Lambda, a FunctionalInterface annotation type was
added to the platform to mark interfaces that are intended to be used in
lambda expressions. I've sent out a code review request to add this
annotation to types in the core-libs area [1].
To assist the security team in adding analogous annotations to your
types, the list of candidate types in for security-related classes in
java.* and javax.* is given below. I recommend sub-tasks of JDK-8005297
"Add FunctionalInterface support to the platform" be used to track the
work of adding @FunctionalInterface annotations to security types.
Thanks,
-Joe
[1]
http://mail.openjdk.java.net/pipermail/core-libs-dev/2013-February/014292.html
jdk/src/share/classes/java/security/DomainCombiner.java:81: Note:
Candidate functional interface
public interface DomainCombiner {
^
jdk/src/share/classes/java/security/KeyStore.java:212: Note: Candidate
functional interface
public static interface LoadStoreParameter {
^
jdk/src/share/classes/java/security/cert/CertPathParameters.java:40:
Note: Candidate functional interface
public interface CertPathParameters extends Cloneable {
^
jdk/src/share/classes/java/security/cert/CertPathValidatorResult.java:41:
Note:
Candidate functional interface
public interface CertPathValidatorResult extends Cloneable {
^
jdk/src/share/classes/java/security/cert/CertStoreParameters.java:49:
Note: Candidate functional interface
public interface CertStoreParameters extends Cloneable {
^
jdk/src/share/classes/java/security/interfaces/ECKey.java:36: Note:
Candidate functional interface
public interface ECKey {
^
jdk/src/share/classes/java/security/interfaces/DSAKey.java:39: Note:
Candidate functional interface
public interface DSAKey {
^
jdk/src/share/classes/java/security/interfaces/RSAKey.java:41: Note:
Candidate functional interface
public interface RSAKey {
^
jdk/src/share/classes/java/security/PrivilegedAction.java:42: Note:
Candidate functional interface
public interface PrivilegedAction<T> {
^
jdk/src/share/classes/java/security/Guard.java:43: Note: Candidate
functional interface
public interface Guard {
^
jdk/src/share/classes/java/security/PrivilegedExceptionAction.java:45:
Note: Candidate functional interface
public interface PrivilegedExceptionAction<T> {
^
jdk/src/share/classes/java/security/Principal.java:39: Note: Candidate
functional interface
public interface Principal {
^
jdk/src/share/classes/java/security/spec/ECField.java:41: Note:
Candidate functional interface
public interface ECField {
^
jdk/src/share/classes/javax/crypto/interfaces/DHKey.java:40: Note:
Candidate functional interface
public interface DHKey {
^
jdk/src/share/classes/javax/security/auth/callback/CallbackHandler.java:68:
Note: Candidate functional interface
public interface CallbackHandler {
^
