RFR: 8240658: Code completion not working for lambdas in method invocations that require type inference

[Jan Lahoda]

When a method invocation requires type inference, and the user is in the process of typing of a (block) lambda that is
a parameter to the method invocation, javac may not, in some cases, perform the type inference, which then may lead to
non working code completion in JShell (and possibly other tools).

For example (in JShell):
Arrays.stream(new Integer[]{1}).forEach(v -> { System.err.println(v.

and press <tab> - this leads to no proposals currently, as the type of "v" is not inferred.

The idea of the proposed patch is to improve the recovery in cases significant for cases where the text is being typed,
and allow type inference in these cases. The type of "v" is then inferred, and the code completion works.

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Commit messages:
 - 8240658: Code completion not working for lambdas in method invocations that require type inference

Changes: https://git.openjdk.java.net/jdk/pull/50/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=50&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8240658
  Stats: 661 lines in 9 files changed: 625 ins; 6 del; 30 mod
  Patch: https://git.openjdk.java.net/jdk/pull/50.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/50/head:pull/50

PR: https://git.openjdk.java.net/jdk/pull/50