Rename and clean the ASTMangler to Blanks

lib/ast_mangler.ex

@@ -1,25 +0,0 @@
-defmodule ASTMangler do
-
-  def expand([do: remainder], replacements) when is_list(replacements) do
-    [do: expand(remainder, replacements)]
-  end
-  def expand(ast, replacements) when is_list(replacements) do
-    {node, _acc} = Macro.prewalk(ast, replacements, fn(node, acc) -> pre(node, acc) end)
-    node
-  end
-  def expand(ast, replacement) do
-    expand(ast, [replacement])
-  end
-
-  def pre(:__, [first | remainder]), do: {first, remainder}
-  def pre(node, acc), do: {node, acc}
-
-
-  def count(ast) do
-    {_node, acc} = Macro.prewalk(ast, 0, fn(node, acc) -> count(node, acc) end)
-    acc
-  end
-
-  def count(:__, acc), do: {node, acc+1}
-  def count(node, acc), do: {node, acc}
-end

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

lib/koans.ex

@@ -1,7 +1,7 @@
 defmodule Koans do
   defmacro koan(name, body) do
     compiled_name = String.to_atom(name)
-    number_of_args = ASTMangler.count(body)
+    number_of_args = Blanks.count(body)
     quote do
       @koans unquote(compiled_name)
 
@@ -20,7 +20,7 @@ defmodule Koans do
 
   defmacro generate_test_method(_name, 0, _body), do: false
   defmacro generate_test_method(name, 1, body) do
-    single_var = ASTMangler.expand(body, Macro.var(:answer, Koans))
+    single_var = Blanks.replace(body, Macro.var(:answer, Koans))
     quote do
       def unquote(name)(answer) do
         converted = {answer}
@@ -30,8 +30,8 @@ defmodule Koans do
     end
   end
   defmacro generate_test_method(name, number_of_args, body) do
-    answer_placeholders = expand(number_of_args)
+    answer_placeholders = create_vars(number_of_args)
-    multi_var = ASTMangler.expand(body, answer_placeholders)
+    multi_var = Blanks.replace(body, answer_placeholders)
     quote do
       def unquote(name)({:multiple, answers}) do
         converted = List.to_tuple(answers)
@@ -41,7 +41,7 @@ defmodule Koans do
     end
   end
 
-  def expand(amount) do
+  def create_vars(amount) do
     Enum.map(0..amount, fn (idx) -> quote do: elem(converted, unquote(idx)) end)
   end
 

test/blanks_test.exs

@@ -1,11 +1,11 @@
-defmodule ASTManglerTest do
+defmodule BlanksTest do
   use ExUnit.Case, async: true
 
   test "simple replacement" do
     ast = quote do: 1 + :__
 
-    mangled = ASTMangler.expand(ast, 37)
+    mangled = Blanks.replace(ast, 37)
-    assert {:+, [context: ASTManglerTest, import: Kernel], [1, 37]} == mangled
+    assert {:+, [context: BlanksTest, import: Kernel], [1, 37]} == mangled
   end
 
   test "Work with multiple different replacements" do
@@ -31,24 +31,24 @@ defmodule ASTManglerTest do
   test "complex example" do
     ast = [do: {:assert, [line: 5], [{:==, [line: 5], [true, :__]}]}]
 
-    assert [do: {:assert, [line: 5], [{:==, [line: 5], [true, true]}]}] == ASTMangler.expand(ast, true)
+    assert [do: {:assert, [line: 5], [{:==, [line: 5], [true, true]}]}] == Blanks.replace(ast, true)
   end
 
   test "multiple arguments" do
     ast = [do: {:assert, [line: 5], [{:==, [line: 5], [:__, :__]}]}]
 
-    assert [do: {:assert, [line: 5], [{:==, [line: 5], [true, false]}]}] == ASTMangler.expand(ast, [true, false])
+    assert [do: {:assert, [line: 5], [{:==, [line: 5], [true, false]}]}] == Blanks.replace(ast, [true, false])
   end
 
   test "counts simple blanks" do
     ast = quote do: 1 + :__
 
-    assert ASTMangler.count(ast) == 1
+    assert Blanks.count(ast) == 1
   end
 
   test "counts multiple blanks" do
     ast = [do: {:assert, [line: 5], [{:==, [line: 5], [:__, :__]}]}]
 
-    assert ASTMangler.count(ast) == 2
+    assert Blanks.count(ast) == 2
   end
 end