Rename and clean the ASTMangler to Blanks

lib/blanks.ex

@@ -0,0 +1,21 @@
+defmodule Blanks do
+  def replace(ast, replacement) when not is_list(replacement), do: replace(ast, [replacement])
+  def replace([do: ast], replacements), do: [do: replace(ast, replacements)]
+  def replace(ast, replacements) do
+    ast
+    |> Macro.prewalk(replacements, &pre/2)
+    |> elem(0)
+  end
+
+  def pre(:__, [first | remainder]), do: {first, remainder}
+  def pre(node, acc), do: {node, acc}
+
+  def count(ast) do
+    ast
+    |> Macro.prewalk(0, &count/2)
+    |> elem(1)
+  end
+
+  def count(:__, acc), do: {node, acc+1}
+  def count(node, acc), do: {node, acc}
+end