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author | Paul Phillips <paulp@improving.org> | 2012-08-08 05:29:43 -0700 |
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committer | Paul Phillips <paulp@improving.org> | 2012-08-08 09:43:29 -0700 |
commit | 802771b403f6dd0f09e01e4e3e1189c70d4b7bec (patch) | |
tree | abf4ddbc39c1bafc2b042748c6be4de18bee85a7 /test/files/neg/pat_unreachable.scala | |
parent | 7d3b2de7b52fec492bc63296d5adf076f68faf0a (diff) | |
download | scala-802771b403f6dd0f09e01e4e3e1189c70d4b7bec.tar.gz scala-802771b403f6dd0f09e01e4e3e1189c70d4b7bec.tar.bz2 scala-802771b403f6dd0f09e01e4e3e1189c70d4b7bec.zip |
Better pattern matcher error message.
For the common case when someone hasn't quite grokked
the significance of lower case in a pattern match. I'd
like to make all the unreachables errors, not warnings,
but there may be a bug or two to clear out first.
class A {
def badEquals(x: Any, y: Any) = x match {
case y => true
case _ => false
}
}
a.scala:3: warning: patterns after a variable pattern cannot match (SLS 8.1.1)
If you intended to match against parameter y of method badEquals, you must use backticks, like: case `y` =>
case y => true
^
a.scala:4: warning: unreachable code due to variable pattern 'y' on line 3
case _ => false
^
two warnings found
Diffstat (limited to 'test/files/neg/pat_unreachable.scala')
-rw-r--r-- | test/files/neg/pat_unreachable.scala | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/test/files/neg/pat_unreachable.scala b/test/files/neg/pat_unreachable.scala index fc0fd41920..1f402e5212 100644 --- a/test/files/neg/pat_unreachable.scala +++ b/test/files/neg/pat_unreachable.scala @@ -8,7 +8,7 @@ object Test extends App { case Seq(x, y, _*) => x::y::Nil case Seq(x, y) => List(x, y) } - + def not_unreachable(xs:Seq[Char]) = xs match { case Seq(x, y, _*) => x::y::Nil case Seq(x) => List(x) @@ -17,4 +17,10 @@ object Test extends App { case Seq(x, y) => x::y::Nil case Seq(x, y, z, _*) => List(x,y) } + + def contrivedExample[A, B, C](a: A, b: B, c: C): Unit = a match { + case b => println("matched b") + case c => println("matched c") + case _ => println("matched neither") + } } |