Merge pull request #918 from alco/iex-h-fix

Make h() in IEx look at Kernel.SpecialForms too

Author: José Valim

lib/iex/lib/iex/helpers.ex

@@ -123,8 +123,17 @@ defmodule IEx.Helpers do
 
   defmacro h({ name, _, args }) when args == [] or is_atom(args) do
     quote do
-      h(unquote(__MODULE__), unquote(name))
-      h(Kernel, unquote(name))
+      candidates = [unquote(__MODULE__), Kernel, Kernel.SpecialForms]
+
+      # If we got at least one :ok, final result will be :ok
+      Enum.reduce candidates, :not_found, fn(mod, flag) ->
+        ret = h(mod, unquote(name))
+        if flag == :ok do
+          :ok
+        else
+          ret
+        end
+      end
     end
   end
 
@@ -134,17 +143,31 @@ defmodule IEx.Helpers do
     end
   end
 
+  defmacrop mfa_exported?(module, function, arity) do
+    quote do
+      function_exported?(unquote(module), unquote(function), unquote(arity)) or
+         macro_exported?(unquote(module), unquote(function), unquote(arity))
+    end
+  end
+
+  defp h_kernel(function, arity) do
+    if mfa_exported?(Kernel, function, arity) do
+      h(Kernel, function, arity)
+    else
+      h(Kernel.SpecialForms, function, arity)
+    end
+  end
+
   @doc false
   def h(:h, 1) do
     h(__MODULE__, :h, 1)
   end
 
   def h(function, arity) when is_atom(function) and is_integer(arity) do
-    if function_exported?(__MODULE__, function, arity) or
-       macro_exported?(__MODULE__, function, arity) do
+    if mfa_exported?(__MODULE__, function, arity) do
       h(__MODULE__, function, arity)
     else
-      h(Kernel, function, arity)
+      h_kernel(function, arity)
     end
   end
 
@@ -166,12 +189,16 @@ defmodule IEx.Helpers do
   end
 
   def h(module, function) when is_atom(module) and is_atom(function) do
-    lc {{f, arity}, _line, _type, _args, doc } inlist module.__info__(:docs),
+    result = lc {{f, arity}, _line, _type, _args, doc } inlist module.__info__(:docs),
        f == function and doc != false do
       h(module, function, arity)
       IO.puts ""
     end
-    :ok
+    if result != [] do
+      :ok
+    else
+      :not_found
+    end
   end
 
   def h(_, _) do
@@ -235,7 +262,7 @@ defmodule IEx.Helpers do
   end
 
   @doc """
-  Prints all types for the given module or prints out a specified type's 
+  Prints all types for the given module or prints out a specified type's
   specification
 
   ## Examples
@@ -265,7 +292,7 @@ defmodule IEx.Helpers do
 
   @doc false
   def t(module, type) when is_atom(type) do
-    types = lc {_, {t, _, _args}} = typespec inlist Kernel.Typespec.beam_types(module), 
+    types = lc {_, {t, _, _args}} = typespec inlist Kernel.Typespec.beam_types(module),
                t == type do
       print_type(typespec)
       typespec
@@ -290,7 +317,7 @@ defmodule IEx.Helpers do
 
   @doc false
   def t(module, type, arity) do
-    types = lc {_, {t, _, args}} = typespec inlist Kernel.Typespec.beam_types(module), 
+    types = lc {_, {t, _, args}} = typespec inlist Kernel.Typespec.beam_types(module),
                length(args) == arity and t == type, do: typespec
 
     case types do
@@ -336,7 +363,7 @@ defmodule IEx.Helpers do
   defmacro s({ :/, _, [{ fun, _, args }, arity] }) when args == [] or is_atom(args) do
     quote do
       s(Kernel, unquote(fun), unquote(arity))
-    end    
+    end
   end
 
   defmacro s(module) do
@@ -461,7 +488,7 @@ defmodule IEx.Helpers do
         flush
     after
       0 -> :ok
-    end  
+    end
   end
 
   defp iex_reloaded do