added tests; fixed #903; made Predef.Map covari...

added tests; fixed #903; made Predef.Map covariant in second parameter.

9 files changed, 90 insertions, 11 deletions

diff --git a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
index b6da9f9b1d..340f403f9f 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
@@ -446,15 +446,11 @@ trait Parsers extends NewScanners with MarkupParsers {
       if (operator eq nme.ERROR) -1
       else {
         val firstCh = operator(0)
-        if (operator(operator.length - 1) == '=' &&
-            firstCh != '<' &&
-            firstCh != '>' &&
-            firstCh != '=' &&
-            firstCh != '!')
-          0
-        else if (((firstCh >= 'A') && (firstCh <= 'Z')) ||
+        if (((firstCh >= 'A') && (firstCh <= 'Z')) ||
             ((firstCh >= 'a') && (firstCh <= 'z')))
           1
+        else if (nme.isOpAssignmentName(operator))
+          0
         else
           firstCh match {
             case '|'             => 2
diff --git a/src/compiler/scala/tools/nsc/symtab/StdNames.scala b/src/compiler/scala/tools/nsc/symtab/StdNames.scala
index 824323f20a..7ddc641f6f 100644
--- a/src/compiler/scala/tools/nsc/symtab/StdNames.scala
+++ b/src/compiler/scala/tools/nsc/symtab/StdNames.scala
@@ -97,7 +97,19 @@ trait StdNames {
     def isSetterName(name: Name) = name.endsWith(SETTER_SUFFIX)
     def isLocalDummyName(name: Name) = name.startsWith(LOCALDUMMY_PREFIX)
     def isOpAssignmentName(name: Name) =
-      name.endsWith(nme.EQL) && name != nme.EQ && !name.endsWith(nme.USCOREEQL)
+      name(name.length - 1) == '=' &&
+      isOperatorCharacter(name(0)) &&
+      name != EQraw && name != NEraw && name != LEraw && name != GEraw
+
+    def isOperatorCharacter(c: Char) = c match {
+      case '~' | '!' | '@' | '#' | '%' |
+           '^' | '*' | '+' | '-' | '<' |
+           '>' | '?' | ':' | '=' | '&' |
+           '|' | '\\'| '/' => true
+      case _ =>
+        val chtp = Character.getType(c)
+        chtp == Character.MATH_SYMBOL || chtp == Character.OTHER_SYMBOL
+      }
 
     /** If `name' is an expandedName, the original name. Otherwise `name' itself.
      *  @see Symbol.expandedName
@@ -373,6 +385,12 @@ trait StdNames {
     val UNARY_- = encode("unary_-")
     val UNARY_! = encode("unary_!")
 
+    // unencoded comparisons
+    val EQraw = newTermName("==")
+    val NEraw = newTermName("!=")
+    val LEraw = newTermName("<=")
+    val GEraw = newTermName(">=")
+
     // value-conversion methods
     val toByte = newTermName("toByte")
     val toShort = newTermName("toShort")
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index eb12867ea9..71a6ceeb34 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -2595,12 +2595,13 @@ trait Typers { self: Analyzer =>
             case ex: TypeError =>
               fun match {
                 case Select(qual, name)
-                if (mode & PATTERNmode) == 0 && nme.isOpAssignmentName(name) =>
+                if (mode & PATTERNmode) == 0 && nme.isOpAssignmentName(name.decode) =>
                   val qual1 = typedQualifier(qual)
                   if (treeInfo.isVariableOrGetter(qual1)) {
                     convertToAssignment(fun, qual1, name, args, ex)
                   } else {
-                    reportTypeError(fun.pos, ex)
+                    if (qual1.symbol.isValue) error(tree.pos, "reassignment to val")
+                    else reportTypeError(fun.pos, ex)
                     setError(tree)
                   }
                 case _ =>
diff --git a/src/library/scala/Predef.scala b/src/library/scala/Predef.scala
index 39d71c3d94..4567f039fe 100644
--- a/src/library/scala/Predef.scala
+++ b/src/library/scala/Predef.scala
@@ -65,7 +65,7 @@ object Predef {
 
   type Function[-A, +B] = Function1[A, B]
 
-  type Map[A, B] = collection.immutable.Map[A, B]
+  type Map[A, +B] = collection.immutable.Map[A, B]
   type Set[A] = collection.immutable.Set[A]
 
   val Map = collection.immutable.Map
diff --git a/test/files/neg/t0903.check b/test/files/neg/t0903.check
new file mode 100644
index 0000000000..db4cd94d2c
--- /dev/null
+++ b/test/files/neg/t0903.check
@@ -0,0 +1,7 @@
+t0903.scala:3: error: reassignment to val
+  x += 1
+    ^
+t0903.scala:4: error: reassignment to val
+  x = 2
+    ^
+two errors found
diff --git a/test/files/neg/t0903.scala b/test/files/neg/t0903.scala
new file mode 100644
index 0000000000..cf8abce97a
--- /dev/null
+++ b/test/files/neg/t0903.scala
@@ -0,0 +1,5 @@
+object Test {
+  val x = 1
+  x += 1
+  x = 2
+}
diff --git a/test/files/pos/t0786.scala b/test/files/pos/t0786.scala
new file mode 100644
index 0000000000..d23cdb741b
--- /dev/null
+++ b/test/files/pos/t0786.scala
@@ -0,0 +1,29 @@
+object ImplicitProblem {
+    class M[T]
+
+    def nullval[T] = null.asInstanceOf[T];
+
+    trait Rep[T] {
+        def eval: int
+    }
+
+    implicit def toRep0(n: int) = new Rep[int] {
+        def eval = 0
+    }
+
+    implicit def toRepN[T](n: M[T])(implicit f: T => Rep[T]) = new Rep[M[T]] {
+        def eval = f(nullval[T]).eval + 1
+    }
+
+    def depth[T <% Rep[T]](n: T) = n.eval
+
+    def main(args: Array[String]) {
+        println(depth(nullval[M[int]]))  // (1) this works
+        println(nullval[M[int]].eval)    // (2) this works
+
+        type m = M[int]
+        println(depth(nullval[m]))     // (3) this doesn't compile on 2.7.RC1
+        println(nullval[m].eval)       // (4) this works
+    }
+
+}
diff --git a/test/files/pos/t0904.scala b/test/files/pos/t0904.scala
new file mode 100644
index 0000000000..28ad30fc2d
--- /dev/null
+++ b/test/files/pos/t0904.scala
@@ -0,0 +1,17 @@
+trait A {
+  def apply(x: Int): Int
+  def update(x: Int, y: Int): Unit
+}
+
+trait B extends A
+
+abstract class Foo {
+  val a: A = null
+  val b: B = null
+
+  a(0) = 1
+  b(0) = 1
+
+  a(0) += 1
+  b(0) += 1 // this one does not type check.
+}
diff --git a/test/files/run/t0677.scala b/test/files/run/t0677.scala
new file mode 100644
index 0000000000..7978e3d142
--- /dev/null
+++ b/test/files/run/t0677.scala
@@ -0,0 +1,6 @@
+object Test extends Application {
+  class X[T] { val a = new Array[Array[T]](3,4) }
+  val x = new X[String]
+  x.a(1)(2) = "hello"
+  assert(x.a(1)(2) == "hello")
+}