Fix and test case for #1565; an anonymous funct...

Fix and test case for #1565; an anonymous function can now be used as
a statement (primarily for use in the interpreter) unless it cannot be
distinguished from a self-type declaration.

3 files changed, 31 insertions, 5 deletions

diff --git a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
index f08b08b3d7..b8b8d1bffb 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
@@ -1075,9 +1075,17 @@ trait Parsers extends NewScanners with MarkupParsers {
               Match(stripParens(t), cases)
             }
           }
-          if (inToken == ARROW && location != InTemplate) {
+          // in order to allow anonymous functions as statements (as opposed to expressions) inside
+          // templates, we have to disambiguate them from self type declarations - bug #1565
+          // The case still missed is unparenthesized single argument, like "x: Int => x + 1", which
+          // may be impossible to distinguish from a self-type and so remains an error.  (See #1564)
+          def lhsIsTypedParamList() = t match {
+            case Parens(xs) if xs forall (_.isInstanceOf[Typed]) => true
+            case _ => false
+          }
+          if (inToken == ARROW && (location != InTemplate || lhsIsTypedParamList)) {
             t = atPos(inSkipToken) {
-              Function(convertToParams(t), if (location == Local) expr() else block())
+              Function(convertToParams(t), if (location != InBlock) expr() else block())
             }
           }
           stripParens(t)
@@ -2501,10 +2509,10 @@ trait Parsers extends NewScanners with MarkupParsers {
           acceptStatSep()
         } else if (isExprIntro) {
           stats += statement(InBlock)
-          if (inToken != RBRACE && inToken != CASE) acceptStatSep()
+          if (inToken != RBRACE && inToken != CASE && inToken != EOF) acceptStatSep()
         } else if (isDefIntro || isLocalModifier || in.token == AT) {
           stats ++= localDef
-          if (inToken == RBRACE || inToken == CASE) {
+          if (inToken == RBRACE || inToken == CASE || inToken == EOF) {
             syntaxError("block must end in result expression, not in definition", false)
             stats += Literal(()).setPos(inCurrentPos)
           } else acceptStatSep()
diff --git a/test/files/neg/xmltruncated6.check b/test/files/neg/xmltruncated6.check
index 6123114560..f638f2f090 100644
--- a/test/files/neg/xmltruncated6.check
+++ b/test/files/neg/xmltruncated6.check
@@ -1,4 +1,4 @@
-xmltruncated6.scala:2: error: ';' expected but eof found.
+xmltruncated6.scala:2: error: in XML literal:  expected end of Scala block
   val stuff = <a>{ "no closing brace"
                                      ^
 one error found
diff --git a/test/files/pos/bug1565.scala b/test/files/pos/bug1565.scala
new file mode 100644
index 0000000000..9a5bfd0882
--- /dev/null
+++ b/test/files/pos/bug1565.scala
@@ -0,0 +1,18 @@
+object Bug1565 {
+  object X0 { 0;  (a : Int, b : Int, c : Int) => println(List(a, b))   }
+  def x() = { 0; (a : Int, b : Int) => println(List(a, b)) ; 0  }
+
+  (a : Int, b : Int) => println(List(a, b))
+
+  // various function syntaxes to exercise the parser
+  val xs = List(1,2,3)
+  xs.filter(x => x < 2)
+  xs.filter((x) => x < 2)
+  xs.filter { x => x < 2 }
+  xs.filter { _ < 2 }
+  xs.filter (_ < 2)
+  xs.foreach { e =>
+    val buf0 = e + 1
+    buf0
+  }
+}
\ No newline at end of file