Merge pull request #1417 from jwarwick/issue_1414

Fix for Issue 1414, Record.__record__(:index) syntax

Author: José Valim

CHANGELOG.md

@@ -25,6 +25,7 @@
   * [Enum] Receiving the index of iteration in `Enum.map/2` and `Enum.each/2` is deprecated in favor of `Stream.with_index/1`
   * [File] `File.iterator/1` and `File.biniterator/1` are deprecated in favor of `IO.stream/1` and `IO.binstream/1`
   * [File] `File.iterator!/2` and `File.biniterator!/2` are deprecated in favor of `File.stream!/2` and `File.binstream!/2`
+  * [Record] `Record.__index__/2` deprecated in favor of `Record.__record__(:index, key)`
 
 * backwards incompatible changes
   * [Kernel] The `Binary.Inspect` protocol has been renamed to `Inspect`

lib/elixir/lib/kernel.ex

@@ -1517,12 +1517,12 @@ defmodule Kernel do
       #=> [name: nil, age: 0]
 
   In order to quickly access the index of a field, one can use
-  the `__index__` function:
+  the `__record__` function with `:index` as the first argument:
 
-      User.__index__(:age)
+      User.__record__(:index, :age)
       #=> 2
 
-      User.__index__(:unknown)
+      User.__record__(:index, :unknown)
       #=> nil
 
   ## Compile-time introspection

lib/elixir/lib/record.ex

@@ -573,7 +573,7 @@ defmodule Record do
   ## Function generation
 
   # Define __record__/1 and __record__/2 as reflection functions
-  # that returns the record names and fields.
+  # that return the record names and fields.
   #
   # Note that fields are *not* keywords. They are in the same
   # order as given as parameter and reflects the order of the
@@ -585,9 +585,26 @@ defmodule Record do
   #
   #     FileInfo.__record__(:name)   #=> FileInfo
   #     FileInfo.__record__(:fields) #=> [atime: nil, mtime: nil]
+  #     FileInfo.__record__(:index, :atime) #=> 1
+  #     FileInfo.__record__(:index, :mtime) #=> 2
   #
   defp reflection(values) do
+    quoted = lc { k, _ } inlist values do
+      index = find_index(values, k, 0)
+      quote do
+        @doc false
+        def __record__(:index, unquote(k)), do: unquote(index + 1)
+      end
+    end
+
     quote do
+      unquote(quoted)
+
+      @doc false
+      def __record__(:index, _), do: nil
+      @doc false
+      def __record__(:index, arg, _), do: __record__(:index, arg)
+
       @doc false
       def __record__(kind, _),      do: __record__(kind)
 

lib/elixir/lib/system.ex

@@ -162,8 +162,8 @@ defmodule System do
   defp write_tmp_dir(dir) do
     case :file.read_file_info(dir) do
       {:ok, info} ->
-        type_index = File.Stat.__index__ :type
-        access_index = File.Stat.__index__ :access
+        type_index = File.Stat.__record__(:index, :type)
+        access_index = File.Stat.__record__(:index, :access)
         case { elem(info, type_index), elem(info, access_index) } do
           { :directory, access } when access in [:read_write, :write] ->
             dir

lib/elixir/test/elixir/record_test.exs

@@ -126,6 +126,16 @@ defmodule RecordTest do
     assert RecordTest.FileInfo.__index__(:atime) == record.__index__(:atime)
   end
 
+  test :__record_index__ do
+    record = RecordTest.DynamicName.new(a: "a", b: "b")
+    assert record.__record__(:index, :a) == 1
+    assert elem(record, record.__record__(:index, :a)) == "a"
+    assert elem(record, record.__record__(:index, :b)) == "b"
+    assert record.__record__(:index, :c) == nil
+    record = RecordTest.FileInfo.new
+    assert RecordTest.FileInfo.__record__(:index, :atime) == record.__record__(:index, :atime)
+  end
+
   test :to_keywords do
     record = RecordTest.DynamicName.new(a: "a", b: "b")
     assert record.to_keywords[:a] == "a"

lib/mix/lib/mix/deps.ex

@@ -82,7 +82,7 @@ defmodule Mix.Deps do
     deps = Enum.filter all_deps, fn(dep) -> dep.app in apps end
 
     # Now we validate the given atoms
-    index = Mix.Dep.__index__(:app)
+    index = Mix.Dep.__record__(:index, :app)
     Enum.each apps, fn(app) ->
       unless List.keyfind(deps, app, index) do
         Mix.shell.info "unknown dependency #{app} for env #{Mix.env}"