JDK-7115044 : Umbrella: Add support for lambda expressions
  • Type: Enhancement
  • Component: tools
  • Sub-Component: javac
  • Affected Version: 8
  • Priority: P2
  • Status: Resolved
  • Resolution: Fixed
  • OS: generic
  • CPU: unknown
  • Submitted: 2011-11-23
  • Updated: 2013-11-20
  • Resolved: 2013-07-05
The Version table provides details related to the release that this issue/RFE will be addressed.

Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availability Release.

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JDK 8
8Fixed
Related Reports
Relates :  
JDK-7162438 - Usage of diamond notation with ?: conditional operator
Relates :  
JDK-8004962 - Code generation crash with lambda and local classes
Relates :  
JDK-7190296 - unsoundness in type-containment implementation
Relates :  
JDK-8005183 - Missing accessor for constructor reference pointing to private inner class ctor
Relates :  
JDK-8026329 - Regression: Type Inferencer can return incorrect type signatures
Relates :  
JDK-8005632 - Inner classes within lambdas cause build failures
Relates :  
JDK-8005653 - Lambdas containing inner classes referencing external type variables do not correctly parameterize the inner class
Relates :  
JDK-8005299 - Add FunctionalInterface checking to javac
Sub Tasks
JDK-7115046 :  
Add AST node for lambda expressions - Closed
JDK-7115049 :  
Add AST node for method references - Closed
JDK-7115050 :  
Add parser support for lambda expressions - Closed
JDK-7115052 :  
Add parser support for method references - Closed
JDK-7129801 :  
Merge the two method applicability routines - Closed
JDK-7132880 :  
Resolve should support nested resolution contexts - Closed
JDK-7133185 :  
Update 292 overload resolution logic to match JLS - Closed
JDK-7133238 :  
Merge proto-kind and proto-type into a single result class - Closed
JDK-7143880 :  
Attr.java has an unsoundness in method arguments attribution - Closed
JDK-7144506 :  
Attr.checkMethod should be called after inference variables have been fixed - Closed
JDK-7148164 :  
attribution code for diamond should not rely on mutable state - Closed
JDK-7148622 :  
Some diagnostic methods do not go through Log.report - Closed
JDK-7151492 :  
Encapsulate check logic into Attr.ResultInfo - Closed
JDK-7151580 :  
Separate DA/DU logic from exception checking logic in Flow.java - Closed
JDK-7154127 :  
Inference cleanup: remove bound check analysis from visitors in Types.java - Closed
JDK-7166552 :  
Inference: cleanup usage of Type.ForAll - Closed
JDK-7175433 :  
Inference cleanup: add helper class to handle inference variables - Closed
JDK-7175538 :  
Integrate efectively final check with DA/DU analysis - Closed
JDK-7175911 :  
Simplify error reporting API in Check.CheckContext interface - Closed
JDK-7177385 :  
Add attribution support for lambda expressions - Closed
JDK-7177386 :  
Add attribution support for method references - Closed
JDK-7177387 :  
Add target-typing support in method context - Closed
JDK-7187104 :  
Inference cleanup: remove redundant exception classes in Infer.java - Closed
JDK-7188968 :  
New instance creation expression using diamond is checked twice - Closed
JDK-7192245 :  
Add parser support for default methods - Closed
JDK-7192246 :  
Add type-checking support for default methods - Closed
JDK-7193913 :  
Cleanup Resolve.findMethod - Closed
JDK-7194586 :  
Add back-end support for invokedynamic - Closed
JDK-8000694 :  
Add generation of lambda implementation code: invokedynamic call, lambda method, adaptor methods - Closed
JDK-8000806 :  
Implement runtime lambda metafactory - Resolved
JDK-8001053 :  
Add javax.lang/com.source support for default methods - Resolved
JDK-8002099 :  
Add support for intersection types in cast expression - Closed
JDK-8003280 :  
Add lambda tests - Closed
JDK-8004099 :  
Bad compiler diagnostic generated when poly expression is passed to non-existent method - Closed
JDK-8004101 :  
Add checks for method reference well-formedness - Closed
JDK-8004102 :  
Add support for generic functional descriptors - Closed
JDK-8004105 :  
Expression statement lambdas should be void-compatible - Resolved
JDK-8005166 :  
Add support for static interface methods - Closed
JDK-8005172 :  
Add support for private interface methods in interfaces - Resolved
JDK-8005179 :  
Cleanup Resolve.AmbiguityError - Closed
JDK-8005184 :  
Restructure DeferredAttr to allow pluggable deferred type completers - Closed
JDK-8005243 :  
Restructure method check code to allow pluggable checkers - Closed
JDK-8005244 :  
Implement overload resolution as per latest spec EDR - Closed
JDK-8005851 :  
Remove support for synchronized interface methods - Closed
JDK-8005852 :  
Treatment of '_' as identifier - Closed
JDK-8005853 :  
Add support for 'package' as access modifier - Closed
JDK-8005854 :  
Add support for array constructor references - Closed
JDK-8007462 :  
Fix provisional applicability for method references - Closed
JDK-8007464 :  
Add graph inference support - Closed
JDK-8007479 :  
Refactor DeferredAttrContext so that it points to parent context - Closed
Description
Add support for lambda expression/method references to the Java compiler. The functionalities to be added are described in this public document:

http://cr.openjdk.java.net/~briangoetz/lambda/lambda-state-3.html

And, also, in the public JSR 335 EDR, available at the following URL:

http://jcp.org/aboutJava/communityprocess/edr/jsr335/index.html
Comments
Tighter handling of raw types means more return types are erased. After the subtask "Attr.checkMethod should be called after inference variables have been fixed" in this umbrella project has been applied, programs like: --------------------------------------------------------------------------------------------- import java.util.List; class ReproOne { static class Baz<T> { public static List<Baz<Object>> getElements(Baz<Object> transcoder) { return null; } } private static void bar(Baz arg) { Baz element = Baz.getElements(arg).get(0); } } //based on a code provided by cushon@google.com at compiler-dev list ------------------------------------------------------------------------------------- which is accepted with warnings by javac 7, are not accepted anymore by javac 8. The javac 8 output for this code is: ReproOne.java:12: error: incompatible types: Object cannot be converted to Baz Baz element = Baz.getElements(arg).get(0); ^ Note: ReproOne.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 1 error What is happening here is that a raw type is being passed to the getElements(Baz<Object>) method which is applicable by subtyping (see the JLS, Java SE 7 Edition, section 15.12.2.2), so an unchecked conversion is necessary for the method to be applicable, so it's return type is erased (see the JLS, Java SE 7 Edition, section 15.12.2.6), in this case the return type of getElements(Baz<Object>) will be java.util.List instead of java.util.List<Baz<Object>> and thus the return type of get(int) will be Object which is not assignment-compatible with Baz. The original discussion and more examples can be found at: http://mail.openjdk.java.net/pipermail/compiler-dev/2013-October/007726.html
08-11-2013
Lambda and method references are now in TL. We can close this tracking issue.
05-07-2013
This issue seems to be triggered a lot more frequently when lambda support is enabled
28-09-2012