1 files changed, 56 insertions, 6 deletions

diff --git a/src/main/scala/scala/async/TransformUtils.scala b/src/main/scala/scala/async/TransformUtils.scala
index b79be87..8838bb3 100644
--- a/src/main/scala/scala/async/TransformUtils.scala
+++ b/src/main/scala/scala/async/TransformUtils.scala
@@ -1,4 +1,4 @@
-/**
+/*
  * Copyright (C) 2012 Typesafe Inc. <http://www.typesafe.com>
  */
 package scala.async
@@ -9,11 +9,34 @@ import reflect.ClassTag
 /**
  * Utilities used in both `ExprBuilder` and `AnfTransform`.
  */
-class TransformUtils[C <: Context](val c: C) {
+private[async] final case class TransformUtils[C <: Context](val c: C) {
 
   import c.universe._
 
-  protected def defaultValue(tpe: Type): Literal = {
+  object name {
+    def suffix(string: String) = string + "$async"
+
+    def suffixedName(prefix: String) = newTermName(suffix(prefix))
+
+    val state       = suffixedName("state")
+    val result      = suffixedName("result")
+    val resume      = suffixedName("resume")
+    val execContext = suffixedName("execContext")
+
+    // TODO do we need to freshen any of these?
+    val tr                = newTermName("tr")
+    val onCompleteHandler = suffixedName("onCompleteHandler")
+
+    val matchRes = "matchres"
+    val ifRes    = "ifres"
+    val await    = "await"
+
+    def fresh(name: TermName): TermName = newTermName(fresh(name.toString))
+
+    def fresh(name: String): String = if (name.toString.contains("$")) name else c.fresh("" + name + "$")
+  }
+
+  def defaultValue(tpe: Type): Literal = {
     val defaultValue: Any =
       if (tpe <:< definitions.BooleanTpe) false
       else if (definitions.ScalaNumericValueClasses.exists(tpe <:< _.toType)) 0
@@ -22,9 +45,22 @@ class TransformUtils[C <: Context](val c: C) {
     Literal(Constant(defaultValue))
   }
 
-  protected def isAwait(fun: Tree) =
+  def isAwait(fun: Tree) =
     fun.symbol == defn.Async_await
 
+  /** Replace all `Ident` nodes referring to one of the keys n `renameMap` with a node
+    * referring to the corresponding new name
+    */
+  def substituteNames(tree: Tree, renameMap: Map[Symbol, Name]): Tree = {
+    val renamer = new Transformer {
+      override def transform(tree: Tree) = tree match {
+        case Ident(_) => (renameMap get tree.symbol).fold(tree)(Ident(_))
+        case _        => super.transform(tree)
+      }
+    }
+    renamer.transform(tree)
+  }
+
   /** Descends into the regions of the tree that are subject to the
     * translation to a state machine by `async`. When a nested template,
     * function, or by-name argument is encountered, the descend stops,
@@ -37,6 +73,9 @@ class TransformUtils[C <: Context](val c: C) {
     def nestedModule(module: ModuleDef) {
     }
 
+    def nestedMethod(module: DefDef) {
+    }
+
     def byNameArgument(arg: Tree) {
     }
 
@@ -47,6 +86,7 @@ class TransformUtils[C <: Context](val c: C) {
       tree match {
         case cd: ClassDef     => nestedClass(cd)
         case md: ModuleDef    => nestedModule(md)
+        case dd: DefDef       => nestedMethod(dd)
         case fun: Function    => function(fun)
         case Apply(fun, args) =>
           val isInByName = isByName(fun)
@@ -68,7 +108,7 @@ class TransformUtils[C <: Context](val c: C) {
     Set(Boolean_&&, Boolean_||)
   }
 
-  protected def isByName(fun: Tree): (Int => Boolean) = {
+  def isByName(fun: Tree): (Int => Boolean) = {
     if (Boolean_ShortCircuits contains fun.symbol) i => true
     else fun.tpe match {
       case MethodType(params, _) =>
@@ -78,7 +118,16 @@ class TransformUtils[C <: Context](val c: C) {
     }
   }
 
-  private[async] object defn {
+  def statsAndExpr(tree: Tree): (List[Tree], Tree) = tree match {
+    case Block(stats, expr) => (stats, expr)
+    case _                  => (List(tree), Literal(Constant(())))
+  }
+
+  def mkVarDefTree(resultType: Type, resultName: TermName): c.Tree = {
+    ValDef(Modifiers(Flag.MUTABLE), resultName, TypeTree(resultType), defaultValue(resultType))
+  }
+
+  object defn {
     def mkList_apply[A](args: List[Expr[A]]): Expr[List[A]] = {
       c.Expr(Apply(Ident(definitions.List_apply), args.map(_.tree)))
     }
@@ -157,4 +206,5 @@ class TransformUtils[C <: Context](val c: C) {
     def ValDef(tree: Tree)(mods: Modifiers, name: TermName, tpt: Tree, rhs: Tree): ValDef =
       copyAttach(tree, c.universe.ValDef(mods, name, tpt, rhs))
   }
+
 }