1 files changed, 60 insertions, 0 deletions
diff --git a/src/compiler/scala/reflect/internal/FreeVars.scala b/src/compiler/scala/reflect/internal/FreeVars.scala
new file mode 100644
index 0000000000..8b6e8b61f3
--- /dev/null
+++ b/src/compiler/scala/reflect/internal/FreeVars.scala
@@ -0,0 +1,60 @@
+package scala.reflect
+package internal
+
+trait FreeVars extends api.FreeVars {
+  self: SymbolTable =>
+
+  object FreeTerm extends FreeTermExtractor {
+    def unapply(freeTerm: FreeTerm): Option[(TermName, Type, Any, String)] =
+      Some(freeTerm.name, freeTerm.info, freeTerm.value, freeTerm.origin)
+  }
+
+  object FreeType extends FreeTypeExtractor {
+    def unapply(freeType: FreeType): Option[(TypeName, Type, String)] =
+      Some(freeType.name, freeType.info, freeType.origin)
+  }
+
+  // [Eugene] am I doing this right?
+  def freeTerms(tree: Tree): List[FreeTerm] = {
+    def isFreeTermSym(sym: Symbol) = sym != null && sym.isFreeTerm
+    def isFreeTermTpe(t: Type) = t != null && isFreeTermSym(t.termSymbol)
+
+    val buf = collection.mutable.Set[Symbol]()
+    tree foreach (sub => {
+      if (sub.tpe != null) buf ++= (sub.tpe collect { case tpe if isFreeTermTpe(tpe) => tpe.typeSymbol })
+      if (sub.symbol != null && isFreeTermSym(sub.symbol)) buf += sub.symbol
+    })
+
+    buf.toList.collect{ case fty: FreeTerm => fty }
+  }
+
+  // [Eugene] am I doing this right?
+  def freeTypes(tree: Tree): List[FreeType] = {
+    def isFreeTypeSym(sym: Symbol) = sym != null && sym.isFreeType
+    def isFreeTypeTpe(t: Type) = t != null && isFreeTypeSym(t.typeSymbol)
+
+    val buf = collection.mutable.Set[Symbol]()
+    tree foreach (sub => {
+      if (sub.tpe != null) buf ++= (sub.tpe collect { case tpe if isFreeTypeTpe(tpe) => tpe.typeSymbol })
+      if (sub.symbol != null && isFreeTypeSym(sub.symbol)) buf += sub.symbol
+    })
+
+    buf.toList.collect{ case fty: FreeType => fty }
+  }
+
+  // todo. also update tpe's of dependent free vars
+  // e.g. if we substitute free$C, then free$C$this should have its info updated
+  // todo. should also transform typetags of types dependent on that free type?
+  // [Eugene] how do I check that the substitution is legal w.r.t fty.info?
+  def substituteFreeTypes(tree0: Tree, subs: Map[FreeType, Type]): Tree = {
+    val tree = tree0.duplicate
+    new TreeTypeSubstituter(subs.keys.toList, subs.values.toList).traverse(tree)
+    tree
+  }
+
+  // [Eugene] how do I check that the substitution is legal w.r.t fty.info?
+  def substituteFreeTypes(tpe0: Type, subs: Map[FreeType, Type]): Type = {
+    val tpe = tpe0 // [Eugene] tpe0.duplicate?
+    tpe.subst(subs.keys.toList, subs.values.toList)
+  }
+}
+\ No newline at end of file