Mark invididual guards of ||, &&, if, and unless as generated

Author: josevalim

lib/elixir/lib/kernel.ex

@@ -1999,6 +1999,12 @@ defmodule Kernel do
     {:case, extra ++ meta, args}
   end
 
+  defp x_is_false_or_nil do
+    quote generated: true do
+      :erlang.orelse(:erlang."=:="(x, false), :erlang."=:="(x, nil))
+    end
+  end
+
   @doc """
   Strictly boolean "or" operator.
 
@@ -2101,7 +2107,7 @@ defmodule Kernel do
       [optimize_boolean: true, type_check: :expr],
       quote do
         case unquote(value) do
-          x when :"Elixir.Kernel".in(x, [false, nil]) -> false
+          x when unquote(x_is_false_or_nil()) -> false
           _ -> true
         end
       end
@@ -2115,7 +2121,7 @@ defmodule Kernel do
       [optimize_boolean: true, type_check: :expr],
       quote do
         case unquote(value) do
-          x when :"Elixir.Kernel".in(x, [false, nil]) -> true
+          x when unquote(x_is_false_or_nil()) -> true
           _ -> false
         end
       end
@@ -4046,7 +4052,7 @@ defmodule Kernel do
       [optimize_boolean: true, type_check: :expr],
       quote do
         case unquote(condition) do
-          x when :"Elixir.Kernel".in(x, [false, nil]) -> unquote(else_clause)
+          x when unquote(x_is_false_or_nil()) -> unquote(else_clause)
           _ -> unquote(do_clause)
         end
       end
@@ -4367,7 +4373,7 @@ defmodule Kernel do
       [type_check: :expr],
       quote do
         case unquote(left) do
-          x when :"Elixir.Kernel".in(x, [false, nil]) ->
+          x when unquote(x_is_false_or_nil()) ->
             x
 
           _ ->
@@ -4410,7 +4416,7 @@ defmodule Kernel do
       [type_check: :expr],
       quote do
         case unquote(left) do
-          x when :"Elixir.Kernel".in(x, [false, nil]) ->
+          x when unquote(x_is_false_or_nil()) ->
             unquote(right)
 
           x ->

lib/elixir/lib/kernel/special_forms.ex

@@ -1975,13 +1975,13 @@ defmodule Kernel.SpecialForms do
   While it is not possible to match against multiple patterns in a single
   clause, it's possible to match against multiple values by using guards:
 
-      iex> case :two do
-      ...>   value when value in [:one, :two] ->
+      iex> case 2 do
+      ...>   value when value in [1, 2] ->
       ...>     "#{value} has been matched"
-      ...>   :three ->
-      ...>     "three has been matched"
+      ...>   3 ->
+      ...>     "3 has been matched"
       ...> end
-      "two has been matched"
+      "2 has been matched"
   """
   defmacro case(condition, clauses), do: error!([condition, clauses])
 

lib/elixir/lib/module/types/pattern.ex

@@ -812,15 +812,6 @@ defmodule Module.Types.Pattern do
     Of.map_fetch(map_fetch, type, key, stack, context)
   end
 
-  # Comparison operators
-  def of_guard({{:., _, [:erlang, function]}, _, args}, _expected, expr, stack, context)
-      when function in [:==, :"/=", :"=:=", :"=/="] do
-    {_args_type, context} =
-      Enum.map_reduce(args, context, &of_guard(&1, term(), expr, stack, &2))
-
-    {boolean(), context}
-  end
-
   # Remote
   def of_guard({{:., _, [:erlang, fun]}, meta, args} = call, expected, _expr, stack, context)
       when is_atom(fun) do

lib/elixir/src/elixir_expand.erl

@@ -6,6 +6,7 @@
 -export([expand/3, expand_args/3, expand_arg/3, format_error/1]).
 -import(elixir_errors, [file_error/4, module_error/4, function_error/4]).
 -include("elixir.hrl").
+-define(kernel, 'Elixir.Kernel').
 
 %% =
 
@@ -794,7 +795,10 @@ expand_case(Meta, Expr, Opts, S, E) ->
 
 rewrite_case_clauses([{do, [
   {'->', FalseMeta, [
-    [{'when', _, [Var, {{'.', _, ['Elixir.Kernel', 'in']}, _, [Var, [false, nil]]}]}],
+    [{'when', _, [{Var, _, ?kernel}, {{'.', _, ['erlang', 'orelse']}, _, [
+      {{'.', _, ['erlang', '=:=']}, _, [{Var, _, ?kernel}, false]},
+      {{'.', _, ['erlang', '=:=']}, _, [{Var, _, ?kernel}, nil]}
+    ]}]}],
     FalseExpr
   ]},
   {'->', TrueMeta, [

lib/elixir/test/elixir/macro_test.exs

@@ -285,7 +285,7 @@ defmodule MacroTest do
     end
 
     defp expand_once_and_clean(quoted, env) do
-      cleaner = &Keyword.drop(&1, [:counter, :type_check])
+      cleaner = &Keyword.drop(&1, [:counter, :type_check, :generated])
 
       quoted
       |> Macro.expand_once(env)
@@ -298,8 +298,15 @@ defmodule MacroTest do
       quoted =
         quote context: Kernel do
           case 1 do
-            unquote(temp_var) when :"Elixir.Kernel".in(unquote(temp_var), [false, nil]) -> false
-            unquote(temp_var) -> unquote(temp_var)
+            unquote(temp_var)
+            when :erlang.orelse(
+                   :erlang."=:="(unquote(temp_var), false),
+                   :erlang."=:="(unquote(temp_var), nil)
+                 ) ->
+              false
+
+            unquote(temp_var) ->
+              unquote(temp_var)
           end
         end
 
@@ -312,8 +319,15 @@ defmodule MacroTest do
       quoted =
         quote context: Kernel do
           case 1 do
-            unquote(temp_var) when :"Elixir.Kernel".in(unquote(temp_var), [false, nil]) -> false
-            unquote(temp_var) -> unquote(temp_var)
+            unquote(temp_var)
+            when :erlang.orelse(
+                   :erlang."=:="(unquote(temp_var), false),
+                   :erlang."=:="(unquote(temp_var), nil)
+                 ) ->
+              false
+
+            unquote(temp_var) ->
+              unquote(temp_var)
           end
         end
 
@@ -382,7 +396,7 @@ defmodule MacroTest do
   end
 
   defp expand_and_clean(quoted, env) do
-    cleaner = &Keyword.drop(&1, [:counter, :type_check])
+    cleaner = &Keyword.drop(&1, [:counter, :type_check, :generated])
 
     quoted
     |> Macro.expand(env)
@@ -395,8 +409,15 @@ defmodule MacroTest do
     quoted =
       quote context: Kernel do
         case 1 do
-          unquote(temp_var) when :"Elixir.Kernel".in(unquote(temp_var), [false, nil]) -> false
-          unquote(temp_var) -> unquote(temp_var)
+          unquote(temp_var)
+          when :erlang.orelse(
+                 :erlang."=:="(unquote(temp_var), false),
+                 :erlang."=:="(unquote(temp_var), nil)
+               ) ->
+            false
+
+          unquote(temp_var) ->
+            unquote(temp_var)
         end
       end
 

lib/elixir/test/erlang/control_test.erl

@@ -43,7 +43,7 @@ optimized_oror_test() ->
   {'case', _, _,
     [{clause, 1,
       [{var, 1, _}],
-      [[{op, 1, 'orelse', _, _}]],
+      [[{op, _, 'orelse', _, _}]],
       [{atom, 1, done}]},
     {clause, 1, [{var, 1, Var}], [], [{var, 1, Var}]}]
   } = to_erl("is_list([]) || :done").