SI-7533 Adds Symbol.isAbstract

Amazingly enough, we've missed the fact that non-type symbols can also
be abstract. Having been enlightened by this, I'm exposing isDeferred
and merging it along with isAbstractType and isAbstractClass into the
unified Symbol.isAbstract method.

2 files changed, 68 insertions, 0 deletions

diff --git a/test/files/run/t7533.check b/test/files/run/t7533.check
new file mode 100644
index 0000000000..fa5b3edc8f
--- /dev/null
+++ b/test/files/run/t7533.check
@@ -0,0 +1,30 @@
+Testing Symbol.isAbstract...
+=======class C=======
+class C => true
+constructor C => false
+value x1 => true
+value x2 => false
+value x2 => false
+method y1 => true
+method y2 => false
+type T1 => true
+type T2 => false
+=======trait T=======
+trait T => true
+method $init$ => false
+value z1 => true
+value z2 => false
+value z2 => false
+method w1 => true
+method w2 => false
+type U1 => true
+type U2 => false
+=======class D=======
+class D => false
+constructor D => false
+value x1 => false
+value x1 => false
+method y1 => false
+=======object M=======
+object M => false
+constructor M => false
diff --git a/test/files/run/t7533.scala b/test/files/run/t7533.scala
new file mode 100644
index 0000000000..46d0b3b02e
--- /dev/null
+++ b/test/files/run/t7533.scala
@@ -0,0 +1,38 @@
+import scala.reflect.runtime.universe._
+
+abstract class C {
+  val x1: Int
+  val x2: Int = 2
+  def y1: Int
+  def y2: Int = 2
+  type T1 <: Int
+  type T2 = Int
+}
+trait T {
+  val z1: Int
+  val z2: Int = 2
+  def w1: Int
+  def w2: Int = 2
+  type U1 <: Int
+  type U2 = Int
+}
+class D extends C {
+  val x1 = 3
+  def y1 = 3
+}
+object M
+
+object Test extends App {
+  println("Testing Symbol.isAbstract...")
+  def test[T: TypeTag] = {
+    val sym = typeOf[T].typeSymbol
+    println(s"=======$sym=======")
+    def printAbstract(sym: Symbol) = println(s"$sym => ${sym.isAbstract}")
+    printAbstract(sym)
+    sym.typeSignature.declarations.sorted.foreach(printAbstract)
+  }
+  test[C]
+  test[T]
+  test[D]
+  test[M.type]
+}
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