Move valueclass functionality into its own ValueClass module.

1 files changed, 36 insertions, 0 deletions

diff --git a/src/dotty/tools/dotc/transform/ValueClasses.scala b/src/dotty/tools/dotc/transform/ValueClasses.scala
new file mode 100644
index 000000000..c5cf44552
--- /dev/null
+++ b/src/dotty/tools/dotc/transform/ValueClasses.scala
@@ -0,0 +1,36 @@
+package dotty.tools.dotc
+package transform
+
+import core._
+import Types._
+import Symbols._
+import SymDenotations._
+import Contexts._
+import Flags._
+
+/** Methods that apply to user-defined value classes */
+object ValueClasses {
+
+  def isDerivedValueClass(d: SymDenotation)(implicit ctx: Context) =
+    d.isClass && d.derivesFrom(defn.AnyValClass) && !d.isPrimitiveValueClass
+
+  def isMethodWithExtension(d: SymDenotation)(implicit ctx: Context) =
+    d.isSourceMethod &&
+      isDerivedValueClass(d.owner) &&
+      !d.isConstructor &&
+      !d.is(SuperAccessor) &&
+      !d.is(Macro)
+
+  /** The member that of a derived value class that unboxes it. */
+  def valueClassUnbox(d: ClassDenotation)(implicit ctx: Context): Symbol =
+    // (info.decl(nme.unbox)).orElse(...)      uncomment once we accept unbox methods
+    d.classInfo.decls
+      .find(d => d.isTerm && d.symbol.is(ParamAccessor))
+      .map(_.symbol)
+      .getOrElse(NoSymbol)
+
+  /** The unboxed type that underlies a derived value class */
+  def underlyingOfValueClass(d: ClassDenotation)(implicit ctx: Context): Type =
+    valueClassUnbox(d).info.resultType
+
+}