From c1327dcd99a6ca84d2550b8e4894ec7ee5ee2420 Mon Sep 17 00:00:00 2001 From: Jason Zaugg Date: Sat, 20 Apr 2013 11:52:21 +0200 Subject: SI-6675 Avoid spurious warning about pattern bind arity. In 692372ce, we added a warning (under -Xlint) when binding a `TupleN` in to a single pattern binder, which wasn't allowed before 2.10.0, and more often than not represents a bug. However, that warning overstretched, and warned even when using a Tuple Pattern to bind to the elements of such a value. This commit checks for this case, and avoids the spurious warnings. A new test case is added for this case to go with the existing test for SI-6675: $ ./tools/partest-ack 6675 % tests-with-matching-paths ... 3 % tests-with-matching-code ... 2 # 3 tests to run. test/partest --show-diff --show-log \ test/files/neg/t6675-old-patmat.scala \ test/files/neg/t6675.scala \ test/files/pos/t6675.scala \ "" Testing individual files testing: [...]/files/pos/t6675.scala [ OK ] Testing individual files testing: [...]/files/neg/t6675-old-patmat.scala [ OK ] testing: [...]/files/neg/t6675.scala [ OK ] All of 3 tests were successful (elapsed time: 00:00:03) --- test/files/pos/t6675.flags | 1 + test/files/pos/t6675.scala | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+) create mode 100644 test/files/pos/t6675.flags create mode 100644 test/files/pos/t6675.scala (limited to 'test/files/pos') diff --git a/test/files/pos/t6675.flags b/test/files/pos/t6675.flags new file mode 100644 index 0000000000..e8fb65d50c --- /dev/null +++ b/test/files/pos/t6675.flags @@ -0,0 +1 @@ +-Xfatal-warnings \ No newline at end of file diff --git a/test/files/pos/t6675.scala b/test/files/pos/t6675.scala new file mode 100644 index 0000000000..f3bebea5be --- /dev/null +++ b/test/files/pos/t6675.scala @@ -0,0 +1,20 @@ +object LeftOrRight { + def unapply[A](value: Either[A, A]): Option[A] = value match { + case scala.Left(x) => Some(x) + case scala.Right(x) => Some(x) + } +} + +object Test { + (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { + case LeftOrRight(pair @ (a, b)) => a // false -Xlint warning: "extractor pattern binds a single value to a Product2 of type (Int, Int)" + } + + (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { + case LeftOrRight((a, b)) => a // false -Xlint warning: "extractor pattern binds a single value to a Product2 of type (Int, Int)" + } + + (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { + case LeftOrRight(a, b) => a // false -Xlint warning: "extractor pattern binds a single value to a Product2 of type (Int, Int)" + } +} -- cgit v1.2.3