Add CollectorWithPC constructor

src/main/scala/inox/transformers/CollectorWithPC.scala

+/* Copyright 2009-2016 EPFL, Lausanne */
+
+package inox
+package transformers
+
+/** A [[Collector]] that collects path conditions */
+trait CollectorWithPC extends TransformerWithPC with Collector
+
+object CollectorWithPC {
+  def apply[T](p: Program)(f: PartialFunction[(p.trees.Expr, p.symbols.Path), T]) = {
+    new CollectorWithPC {
+
+      type R = T
+      val trees: p.trees.type = p.trees
+      val symbols: p.symbols.type = p.symbols
+      import trees.Expr
+      import symbols.Path
+      val initEnv: Path = Path.empty
+
+      protected def step(e: Expr, env: Path): List[(T, Path)] = {
+        f.lift((e, env)).map((_, env)).toList
+      }
+
+    }
+  }
+}

src/main/scala/inox/transformers/TransformerWithPC.scala

@@ -95,6 +95,3 @@ trait TransformerWithPC extends Transformer {
   }
 
 }
-
-/** A [[Collector]] that collects path conditions */
-trait CollectorWithPC extends TransformerWithPC with Collector