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author | Grzegorz Kossakowski <grzegorz.kossakowski@gmail.com> | 2014-02-25 13:50:19 +0100 |
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committer | Grzegorz Kossakowski <grzegorz.kossakowski@gmail.com> | 2014-02-25 13:50:19 +0100 |
commit | 1ea43ffb2286d63e133839c1ea0b09449b0ac168 (patch) | |
tree | 2d003de0ec0e2687eaef214d65e46922b9e86264 | |
parent | 7c709e122f7471353749525cff15602783fb348c (diff) | |
parent | 12dc4a28da8d3631734603c896d2ee1ba21b31d6 (diff) | |
download | scala-1ea43ffb2286d63e133839c1ea0b09449b0ac168.tar.gz scala-1ea43ffb2286d63e133839c1ea0b09449b0ac168.tar.bz2 scala-1ea43ffb2286d63e133839c1ea0b09449b0ac168.zip |
Merge pull request #3566 from adriaanm/t6455
SI-6455 no longer rewrite .withFilter to .filter
-rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/Typers.scala | 2 | ||||
-rw-r--r-- | src/library/scala/util/Try.scala | 29 | ||||
-rw-r--r-- | test/files/neg/t6455.check | 4 | ||||
-rw-r--r-- | test/files/neg/t6455.flags | 1 | ||||
-rw-r--r-- | test/files/neg/t6455.scala | 6 | ||||
-rw-r--r-- | test/files/scalacheck/quasiquotes/TypecheckedProps.scala | 2 | ||||
-rw-r--r-- | test/junit/scala/util/TryTest.scala | 35 |
7 files changed, 77 insertions, 2 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala index 8a3ceb3aca..1004777f23 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala @@ -4715,7 +4715,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper UnstableTreeError(qualTyped) ) val tree1 = name match { - case nme.withFilter => tryWithFilterAndFilter(tree, qualStableOrError) + case nme.withFilter if !settings.future => tryWithFilterAndFilter(tree, qualStableOrError) case _ => typedSelect(tree, qualStableOrError, name) } def sym = tree1.symbol diff --git a/src/library/scala/util/Try.scala b/src/library/scala/util/Try.scala index 89db57a55e..b0cf122f2a 100644 --- a/src/library/scala/util/Try.scala +++ b/src/library/scala/util/Try.scala @@ -111,6 +111,35 @@ sealed abstract class Try[+T] { */ def filter(p: T => Boolean): Try[T] + /** Creates a non-strict filter, which eventually converts this to a `Failure` + * if the predicate is not satisfied. + * + * Note: unlike filter, withFilter does not create a new Try. + * Instead, it restricts the domain of subsequent + * `map`, `flatMap`, `foreach`, and `withFilter` operations. + * + * As Try is a one-element collection, this may be a bit overkill, + * but it's consistent with withFilter on Option and the other collections. + * + * @param p the predicate used to test elements. + * @return an object of class `WithFilter`, which supports + * `map`, `flatMap`, `foreach`, and `withFilter` operations. + * All these operations apply to those elements of this Try + * which satisfy the predicate `p`. + */ + @inline final def withFilter(p: T => Boolean): WithFilter = new WithFilter(p) + + /** We need a whole WithFilter class to honor the "doesn't create a new + * collection" contract even though it seems unlikely to matter much in a + * collection with max size 1. + */ + class WithFilter(p: T => Boolean) { + def map[U](f: T => U): Try[U] = Try.this filter p map f + def flatMap[U](f: T => Try[U]): Try[U] = Try.this filter p flatMap f + def foreach[U](f: T => U): Unit = Try.this filter p foreach f + def withFilter(q: T => Boolean): WithFilter = new WithFilter(x => p(x) && q(x)) + } + /** * Applies the given function `f` if this is a `Failure`, otherwise returns this if this is a `Success`. * This is like `flatMap` for the exception. diff --git a/test/files/neg/t6455.check b/test/files/neg/t6455.check new file mode 100644 index 0000000000..8f2aad0b9e --- /dev/null +++ b/test/files/neg/t6455.check @@ -0,0 +1,4 @@ +t6455.scala:5: error: value withFilter is not a member of object O + O.withFilter(f => true) + ^ +one error found diff --git a/test/files/neg/t6455.flags b/test/files/neg/t6455.flags new file mode 100644 index 0000000000..112fc720a0 --- /dev/null +++ b/test/files/neg/t6455.flags @@ -0,0 +1 @@ +-Xfuture
\ No newline at end of file diff --git a/test/files/neg/t6455.scala b/test/files/neg/t6455.scala new file mode 100644 index 0000000000..ebbb37f1cd --- /dev/null +++ b/test/files/neg/t6455.scala @@ -0,0 +1,6 @@ +object O { def filter(p: Int => Boolean): O.type = this } + +class Test { + // should not compile because we no longer rewrite withFilter => filter under -Xfuture + O.withFilter(f => true) +}
\ No newline at end of file diff --git a/test/files/scalacheck/quasiquotes/TypecheckedProps.scala b/test/files/scalacheck/quasiquotes/TypecheckedProps.scala index 432c0959c9..7c4cb0306e 100644 --- a/test/files/scalacheck/quasiquotes/TypecheckedProps.scala +++ b/test/files/scalacheck/quasiquotes/TypecheckedProps.scala @@ -44,7 +44,7 @@ object TypecheckedProps extends QuasiquoteProperties("typechecked") { val enums = fq"foo <- new Foo" :: fq"if foo != null" :: Nil val body = q"foo" val q"$_; for(..$enums1) yield $body1" = typecheck(q""" - class Foo { def map(f: Any => Any) = this; def filter(cond: Any => Boolean) = this } + class Foo { def map(f: Any => Any) = this; def withFilter(cond: Any => Boolean) = this } for(..$enums) yield $body """) assert(enums1 ≈ enums) diff --git a/test/junit/scala/util/TryTest.scala b/test/junit/scala/util/TryTest.scala new file mode 100644 index 0000000000..03604a8065 --- /dev/null +++ b/test/junit/scala/util/TryTest.scala @@ -0,0 +1,35 @@ +package scala.util + +import org.junit.runner.RunWith +import org.junit.runners.JUnit4 +import org.junit.Test +import org.junit.Assert._ + +/* Test Try's withFilter method, which was added along with the -Xfuture fix for SI-6455 */ +@RunWith(classOf[JUnit4]) +class TryTest { + @Test + def withFilterFail(): Unit = { + val fail = for (x <- util.Try(1) if x > 1) yield x + assert(fail.isFailure) + } + + @Test + def withFilterSuccess(): Unit = { + val success1 = for (x <- util.Try(1) if x >= 1) yield x + assertEquals(success1, util.Success(1)) + } + + @Test + def withFilterFlatMap(): Unit = { + val successFlatMap = for (x <- util.Try(1) if x >= 1; y <- util.Try(2) if x < y) yield x + assertEquals(successFlatMap, util.Success(1)) + } + + @Test + def withFilterForeach(): Unit = { + var ok = false + for (x <- util.Try(1) if x == 1) ok = x == 1 + assert(ok) + } +}
\ No newline at end of file |