move fresh name creator into scala.reflect.internal.util

2 files changed, 34 insertions, 10 deletions

diff --git a/src/reflect/scala/reflect/internal/BuildUtils.scala b/src/reflect/scala/reflect/internal/BuildUtils.scala
index b46408624c..39dfe60ecf 100644
--- a/src/reflect/scala/reflect/internal/BuildUtils.scala
+++ b/src/reflect/scala/reflect/internal/BuildUtils.scala
@@ -131,18 +131,11 @@ trait BuildUtils { self: SymbolTable =>
 
     def RefTree(qual: Tree, sym: Symbol) = self.RefTree(qual, sym.name) setSymbol sym
 
-    def withFreshTermName[T](prefix: String)(f: TermName => T): T = f(TermName(freshName(prefix)))
+    def withFreshTermName[T](prefix: String)(f: TermName => T): T = f(TermName(freshNameCreator.newName(prefix)))
 
-    def withFreshTypeName[T](prefix: String)(f: TypeName => T): T = f(TypeName(freshName(prefix)))
+    def withFreshTypeName[T](prefix: String)(f: TypeName => T): T = f(TypeName(freshNameCreator.newName(prefix)))
 
-    object freshName {
-      private val counters = collection.mutable.HashMap[String, Int]() withDefaultValue 0
-      def apply(prefix: String): String = {
-        val safePrefix = prefix.replaceAll("""[<>]""", """\$""")
-        counters(safePrefix) += 1
-        safePrefix + counters(safePrefix)
-      }
-    }
+    private val freshNameCreator = new util.FreshNameCreator
 
     object FlagsRepr extends FlagsReprExtractor {
       def apply(bits: Long): FlagSet = bits
diff --git a/src/reflect/scala/reflect/internal/util/FreshNameCreator.scala b/src/reflect/scala/reflect/internal/util/FreshNameCreator.scala
new file mode 100644
index 0000000000..8fe4a715f3
--- /dev/null
+++ b/src/reflect/scala/reflect/internal/util/FreshNameCreator.scala
@@ -0,0 +1,31 @@
+/* NSC -- new Scala compiler
+ * Copyright 2005-2013 LAMP/EPFL
+ * @author  Martin Odersky
+ */
+
+package scala.reflect.internal
+package util
+
+import scala.collection.mutable
+
+class FreshNameCreator {
+  protected var counter = 0
+  protected val counters = mutable.HashMap[String, Int]() withDefaultValue 0
+
+  /**
+   * Create a fresh name with the given prefix. It is guaranteed
+   * that the returned name has never been returned by a previous
+   * call to this function (provided the prefix does not end in a digit).
+   */
+  def newName(prefix: String): String = {
+    val safePrefix = prefix.replaceAll("""[<>]""", """\$""")
+    counters(safePrefix) += 1
+
+    safePrefix + counters(safePrefix)
+  }
+
+  def newName(): String = {
+    counter += 1
+    "$" + counter + "$"
+  }
+}