From e9334fb7dc406d0e86c08da5fc40529022161f02 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Valim?= <jose.valim@plataformatec.com.br>
Date: Mon, 5 Nov 2012 14:51:51 +0100
Subject: [PATCH] Tidy up Typespec API, improve docs

---
 lib/elixir/lib/kernel/typespec.ex        | 451 +++++++++++++----------
 lib/elixir/lib/protocol.ex               |  16 +-
 lib/elixir/src/elixir_module.erl         |   8 -
 lib/elixir/test/elixir/typespec_test.exs | 150 ++++----
 lib/iex/lib/iex/helpers.ex               | 123 ++++---
 5 files changed, 406 insertions(+), 342 deletions(-)

diff --git a/lib/elixir/lib/kernel/typespec.ex b/lib/elixir/lib/kernel/typespec.ex
index 3b977b7f1d..f6ec450e4b 100644
--- a/lib/elixir/lib/kernel/typespec.ex
+++ b/lib/elixir/lib/kernel/typespec.ex
@@ -1,24 +1,69 @@
 defmodule Kernel.Typespec do
-  @moduledoc false
+  @moduledoc """
+  Holds macros and functions for working with typespecs.
 
+  The attributes `@type`, `@opaque`, `@typep`, `@spec` and
+  `@callback` available in modules are handled by the equivalent
+  macros defined by this module.
+
+  See http://www.erlang.org/doc/reference_manual/typespec.html
+  for more information.
+  """
+
+  @doc """
+  Defines a type.
+  This macro is the one responsible to handle the attribute @type.
+
+  ## Examples
+
+      @type my_type :: atom
+
+  """
   defmacro deftype(type) do
     quote do
       Kernel.Typespec.deftype(:type, (quote line: :keep, do: unquote(type)), __ENV__)
     end
   end
 
+  @doc """
+  Defines an opaque type.
+  This macro is the one responsible to handle the attribute @opaque.
+
+  ## Examples
+
+      @opaque my_type :: atom
+
+  """
   defmacro defopaque(type) do
     quote do
       Kernel.Typespec.deftype(:opaque, (quote line: :keep, do: unquote(type)), __ENV__)
     end
   end
 
+  @doc """
+  Defines a private type.
+  This macro is the one responsible to handle the attribute @typep.
+
+  ## Examples
+
+      @typep my_type :: atom
+
+  """
   defmacro deftypep(type) do
     quote do
       Kernel.Typespec.deftype(:typep, (quote line: :keep, do: unquote(type)), __ENV__)
     end
   end
 
+  @doc """
+  Defines a spec.
+  This macro is the one responsible to handle the attribute @spec.
+
+  ## Examples
+
+      @spec add(number, number), do: number
+
+  """
   defmacro defspec(spec, block) do
     quote do
       Kernel.Typespec.defspec(:spec, (quote line: :keep, do: unquote spec),
@@ -26,6 +71,15 @@ defmodule Kernel.Typespec do
     end
   end
 
+  @doc """
+  Defines a callback.
+  This macro is the one responsible to handle the attribute @callback.
+
+  ## Examples
+
+      @callback add(number, number), do: number
+
+  """
   defmacro defcallback(spec, block) do
     quote do
       Kernel.Typespec.defspec(:callback, (quote line: :keep, do: unquote spec),
@@ -33,6 +87,174 @@ defmodule Kernel.Typespec do
     end
   end
 
+  ## Helpers
+
+  @doc """
+  Defines a `type`, `typep` or `opaque` by receiving Erlang's typespec.
+  """
+  def define_type(module, kind, { name, _, vars } = type) when kind in [:type, :typep, :opaque] do
+    { kind, export } =
+      case kind do
+        :type   -> { :type, true }
+        :typep  -> { :type, false }
+        :opaque -> { :opaque, true }
+      end
+
+    Module.compile_typespec module, kind, type
+
+    if export do
+      Module.compile_typespec module, :export_type, [{ name, length(vars) }]
+    end
+
+    type
+  end
+
+  @doc """
+  Defines a `spec` by receiving Erlang's typespec.
+  """
+  def define_spec(module, tuple, definition) do
+    Module.compile_typespec module, :spec, { tuple, definition }
+  end
+
+  @doc """
+  Defines a `callback` by receiving Erlang's typespec.
+  """
+  def define_callback(module, tuple, definition) do
+    Module.compile_typespec module, :callback, { tuple, definition }
+  end
+
+  @doc """
+  Returns true if the current module defines a given type
+  (private, opaque or not). This function is only available
+  for modules being compiled.
+  """
+  def defines_type?(module, name, arity) do
+    finder = match?({ ^name, _, vars } when length(vars) == arity, &1)
+    :lists.any(finder, Module.get_attribute(module, :type)) or
+      :lists.any(finder, Module.get_attribute(module, :opaque))
+  end
+
+  @doc """
+  Returns true if the current module defines a given spec.
+  This function is only available for modules being compiled.
+  """
+  def defines_spec?(module, name, arity) do
+    tuple = { name, arity }
+    :lists.any(match?(^tuple, &1), Module.get_attribute(module, :spec))
+  end
+
+  @doc """
+  Returns true if the current module defines a callback.
+  This function is only available for modules being compiled.
+  """
+  def defines_callback?(module, name, arity) do
+    tuple = { name, arity }
+    :lists.any(match?(^tuple, &1), Module.get_attribute(module, :callback))
+  end
+
+  @doc """
+  Converts a spec clause back to Elixir AST.
+  Returns a 2-items tuple with the spec arguments and return result.
+  """
+  def spec_to_ast({ :type, _line, :fun, [{:type, _, :product, args},result] }) do
+    args = lc arg inlist args, do: typespec_to_ast(arg)
+    { args, typespec_to_ast(result) }
+  end
+
+  def spec_to_ast({ :type, _, :fun, [] }) do
+    { [], quote do: term }
+  end
+
+  @doc """
+  Converts a type clause back to Elixir AST.
+  """
+  def type_to_ast({ name, type, args }) do
+    args = lc arg inlist args, do: typespec_to_ast(arg)
+    quote do: unquote(name)(unquote_splicing(args)) :: unquote(typespec_to_ast(type))
+  end
+
+  @doc """
+  Returns all types available from the beam.
+
+  It is returned as a list of tuples where the first
+  element is the type (`:typep`, `:type` and `:opaque`).
+
+  The module has to have a corresponding beam file
+  on the file system.
+  """
+  def beam_types(module) do
+    case abstract_code(module) do
+      { :ok, abstract_code } ->
+        exported_types = lc { :attribute, _, :export_type, types } inlist abstract_code, do: types
+        exported_types = List.flatten(exported_types)
+
+        lc { :attribute, _, kind, { name, _, args } = type } inlist abstract_code, kind in [:opaque, :type] do
+          cond do
+            kind == :opaque -> { :opaque, type }
+            List.member?(exported_types, { name, length(args) }) -> { :type, type }
+            true -> { :typep, type }
+          end
+        end
+      _ ->
+        []
+    end
+  end
+
+  @doc """
+  Returns all specs available from the beam.
+
+  It is returned as a list of tuples where the first
+  element is spec name and arity and the second is the spec.
+
+  The module has to have a corresponding beam file
+  on the file system.
+  """
+  def beam_specs(module) do
+    from_abstract_code(module, :spec)
+  end
+
+  @doc """
+  Returns all callbacks available from the beam.
+
+  It is returned as a list of tuples where the first
+  element is spec name and arity and the second is the spec.
+
+  The module has to have a corresponding beam file
+  on the file system.
+  """
+  def beam_callbacks(module) do
+    from_abstract_code(module, :callback)
+  end
+
+  defp from_abstract_code(module, kind) do
+    case abstract_code(module) do
+      { :ok, abstract_code } ->
+        lc { :attribute, _, abs_kind, value } inlist abstract_code, kind == abs_kind, do: value
+      _ ->
+        []
+    end
+  end
+
+  defp abstract_code(module) do
+    case :beam_lib.chunks(abstract_code_beam(module), [:abstract_code]) do
+      {:ok, { _, [{ :abstract_code, { raw_abstract_v1, abstract_code } }] } } ->
+        { :ok, abstract_code }
+      _ ->
+        []
+    end
+  end
+
+  defp abstract_code_beam(module) when is_atom(module) do
+    case :code.which(module) do
+      :non_existing -> module
+      file -> file
+    end
+  end
+
+  defp abstract_code_beam(binary) when is_binary(binary) do
+    binary
+  end
+
   ## Macro callbacks
 
   @doc false
@@ -44,7 +266,7 @@ defmodule Kernel.Typespec do
     do_deftype(kind, type, { :term, caller.line, nil }, caller)
   end
 
-  defp do_deftype(raw_kind, { name, _, args }, definition, caller) do
+  defp do_deftype(kind, { name, _, args }, definition, caller) do
     args =
       if is_atom(args) do
         []
@@ -52,26 +274,13 @@ defmodule Kernel.Typespec do
         lc(arg inlist args, do: variable(arg))
       end
 
-    { kind, export } =
-      case raw_kind do
-        :type   -> { :type, true }
-        :typep  -> { :type, false }
-        :opaque -> { :opaque, true }
-      end
-
     vars = lc { :var, _, var } inlist args, do: var
     spec = typespec(definition, vars, caller)
 
     vars = lc { :var, _, _ } = var inlist args, do: var
     type = { name, spec, vars }
 
-    Module.compile_typespec caller.module, kind, type
-
-    if export do
-      Module.compile_typespec(caller.module, :export_type, [{ name, length(vars) }])
-    end
-
-    { raw_kind, type }
+    define_type(caller.module, kind, type)
   end
 
   @doc false
@@ -83,224 +292,68 @@ defmodule Kernel.Typespec do
     code
   end
 
-  ## Helpers
+  ## To AST conversion
 
-  @doc """
-  Returns true if the current module defines a given type
-  (opaque or not). This function is only available for modules
-  being compiled.
-  """
-  def defines_type?(module, name, arity) do
-    finder = match?({ ^name, _, vars } when length(vars) == arity, &1)
-    :lists.any(finder, Module.get_attribute(module, :type)) or
-      :lists.any(finder, Module.get_attribute(module, :opaque))
-  end
-
-  @doc """
-  Defines a callback from a spec if one is available.
-  Returns true if successful, false otherwise.
-  """
-  def callback_from_spec(module, name, arity) do
-    tuple = { name, arity }
-    specs = Module.get_attribute(module, :spec)
-
-    found = lc { k, v } inlist specs, k == tuple do
-      Module.compile_typespec(module, :callback, { tuple, v })
-      true
-    end
-
-    found != []
-  end
-
-  @doc """
-  Returns type spec retrieved from a BEAM file in a readable form
-  """
-  def to_binary(typespec) do
-    Macro.to_binary(typespec_to_ast(typespec))
-  end
-
-  ## to_ast
-
-  defp typespec_to_ast({{:spec, {name, _arity}}, args}) do
-    contents = lc arg inlist args do
-      {:__block__, _, [v]} = spec_typespec_to_ast(arg)
-      [product|args] = Enum.reverse(v)
-      args = Enum.reverse(args)
-      quote do
-        @spec unquote(name)(unquote_splicing(args)), unquote(product)
-      end
-    end
-    quote do
-      unquote_splicing(contents)
-    end
-  end
-
-  defp typespec_to_ast({:type, {name, type, args}}) do
-    args = lc arg inlist args, do: typespec_to_ast(arg)
-    quote do: @type unquote(name)(unquote_splicing(args)) :: unquote(typespec_to_ast(type))
-  end
-
-  defp typespec_to_ast({:typep, {name, type, args}}) do
-    args = lc arg inlist args, do: typespec_to_ast(arg)
-    quote do: @typep unquote(name)(unquote_splicing(args)) :: unquote(typespec_to_ast(type))
-  end
-
-  defp typespec_to_ast({:opaque, {name, type, args}}) do
-    args = lc arg inlist args, do: typespec_to_ast(arg)
-    quote do: @opaque unquote(name)(unquote_splicing(args)) :: unquote(typespec_to_ast(type))
-  end
-
-  defp typespec_to_ast({:type, line, :tuple, :any}) do
+  defp typespec_to_ast({ :type, line, :tuple, :any }) do
     typespec_to_ast({:type, line, :tuple, []})
   end
 
-  defp typespec_to_ast({:type, line, :tuple, args}) do
+  defp typespec_to_ast({ :type, line, :tuple, args }) do
     args = lc arg inlist args, do: typespec_to_ast(arg)
     { :{}, line, args }
   end
 
-  defp typespec_to_ast({:type, _line, :binary, [arg1, arg2]}) do
+  defp typespec_to_ast({ :type, line, :binary, [arg1, arg2] }) do
     [arg1, arg2] = lc arg inlist [arg1, arg2], do: typespec_to_ast(arg)
     cond do
       arg2 == 0 ->
-        quote do: <<_ :: unquote(arg1)>>
+        quote line: line, do: <<_ :: unquote(arg1)>>
       arg1 == 0 ->
-        quote do: <<_ :: _ * unquote(arg2)>>
+        quote line: line, do: <<_ :: _ * unquote(arg2)>>
       true ->
-        quote do: <<_ :: unquote(arg1) * unquote(arg2)>>
+        quote line: line, do: <<_ :: unquote(arg1) * unquote(arg2)>>
     end
   end
 
-  defp typespec_to_ast({:type, _line, :union, args}) do
+  defp typespec_to_ast({ :type, line, :union, args }) do
     args = lc arg inlist args, do: typespec_to_ast(arg)
     Enum.reduce tl(args), hd(args),
-      fn(arg, expr) ->
-        quote do: unquote(expr) | unquote(arg)
-      end
+      fn(arg, expr) -> { :|, line, [expr, arg] } end
   end
 
-  defp typespec_to_ast({:type, _line, :fun, [{:type, _, :product, args},result]}) do
+  defp typespec_to_ast({ :type, line, :fun, [{:type, _, :product, args},result] }) do
     args = lc arg inlist args, do: typespec_to_ast(arg)
-    quote do
-      fun(unquote_splicing(args ++ [[do: typespec_to_ast(result)]]))
-    end
+    { :fun, line, args ++ [[do: typespec_to_ast(result)]] }
   end
 
-  defp typespec_to_ast({:type, _, :fun, []}) do
-    quote do: fun()
+  defp typespec_to_ast({ :type, line, :fun, [] }) do
+    { :fun, line, [] }
   end
 
-  defp typespec_to_ast({:type, _, name, args}) do
+  defp typespec_to_ast({ :type, line, name, args }) do
     args = lc arg inlist args, do: typespec_to_ast(arg)
-    quote do: unquote(name)(unquote_splicing(args))
+    { name, line, args }
   end
 
-  defp typespec_to_ast({:var, line, var}) do
-    quote hygiene: false, do: unquote({var, line, nil})
+  defp typespec_to_ast({ :var, line, var }) do
+    { var, line, nil }
   end
 
-  defp typespec_to_ast({:remote_type, _line, [mod, name, args]}) do
+  defp typespec_to_ast({ :remote_type, line, [mod, name, args] }) do
     args = lc arg inlist args, do: typespec_to_ast(arg)
-    quote do: unquote(typespec_to_ast(mod)).unquote(typespec_to_ast(name))(unquote_splicing(args))
+    dot  = { :., line, [typespec_to_ast(mod), typespec_to_ast(name)] }
+    { dot, line, args }
   end
 
-  defp typespec_to_ast({:ann_type, _line, [var, type]}) do
-    quote do: unquote(typespec_to_ast(var)) :: unquote(typespec_to_ast(type))
+  defp typespec_to_ast({ :ann_type, line, [var, type] }) do
+    { :::, line, [typespec_to_ast(var), typespec_to_ast(type)] }
   end
 
-  defp typespec_to_ast({t, _line, imm}) when is_atom(t) do
-    imm
+  defp typespec_to_ast({ t, _line, atom }) when is_atom(t) do
+    atom
   end
 
-  defp spec_typespec_to_ast({:type, _line, :fun, [{:type, _, :product, args},result]}) do
-    args = lc arg inlist args, do: typespec_to_ast(arg)
-    quote do
-      [unquote_splicing(args), [do: unquote(typespec_to_ast(result))]]
-    end
-  end
-
-  defp spec_typespec_to_ast({:type, _, :fun, []}) do
-    quote do: []
-  end
-
-  @doc """
-  Retrieves all type specifications from a module. 
-
-  The module has to have a corresponding beam file on the file system.
-  """
-  def types(module) do
-    types(module, nil, nil)
-  end
-
-  @doc """
-  Retrieves all type specifications from a module with a given name and arity. 
-  
-  The module has to have a corresponding beam file on the file system.
-  """
-  def types(module, type, arity) do
-    case abstract_code(module) do
-      {:ok, abstract_code} ->
-        exported_types = List.flatten(lc {:attribute, _, :export_type, types} inlist abstract_code, do: types)      
-        lc {:attribute, _, type_a, {t, _, a} = ti} inlist abstract_code, type_a in [:opaque, :type], (nil?(type) and nil?(arity)) or (t == type and length(a) == arity) do
-          cond do
-          type_a == :opaque ->
-            {:opaque, ti}
-          List.member?(exported_types, {t, length(a)}) ->
-            {:type, ti}
-          true ->
-            {:typep, ti}
-          end
-        end
-      _ ->
-        []
-    end
-  end
-
-
-  @doc """
-  Retrieves all functions specifications from a module. 
-  
-  The module has to have a corresponding beam file on the file system.
-  """
-  def specs(module) do
-    specs(module, nil, nil)
-  end
-
-  @doc """
-  Retrieves all functions specifications from a module for a given name and arity. 
-  
-  The module has to have a corresponding beam file on the file system.
-  """
-  def specs(module, function, arity) do
-    case abstract_code(module) do
-      {:ok, abstract_code} ->
-        lc {:attribute, _, :spec, {{f,a}=fa, s}} inlist abstract_code, (nil?(function) and nil?(arity)) or (f == function and a == arity), do: {{:spec, fa}, s}
-      _ ->
-        []
-    end
-  end
-
-
-  defp abstract_code(module) do
-    case :beam_lib.chunks(abstract_code_beam(module), [:abstract_code]) do
-      {:ok, {_, [{:abstract_code, {raw_abstract_v1, abstract_code}}]}} ->
-        {:ok, abstract_code}
-      _ -> 
-        :error
-    end
-  end  
-
-  defp abstract_code_beam(module) when is_atom(module) do
-    case :code.which(module) do
-      :non_existing -> module
-      file -> file
-    end
-  end
-  defp abstract_code_beam(binary) when is_binary(binary) do
-    binary
-  end
-
-  ## Typespec conversion
+  ## From AST conversion
 
   # Handle unions
   defp typespec({ :|, line, [_,_] } = exprs, vars, caller) do
@@ -400,7 +453,7 @@ defmodule Kernel.Typespec do
 
   # Handle local calls
   defp typespec({:string, line, arguments}, vars, caller) do
-    IO.write "#{caller.file}.#{caller.line}: warning: string() type use is discouraged. For character lists,  use char_list() type, for strings, String.t()\n"
+    IO.write "#{caller.file}:#{caller.line}: warning: string() type use is discouraged. For character lists,  use char_list() type, for strings, String.t()\n"
     arguments = lc arg inlist arguments, do: typespec(arg, vars, caller)
     { :type, line, :string, arguments }
   end
@@ -432,7 +485,7 @@ defmodule Kernel.Typespec do
   end
 
   defp typespec(l, _, _) when is_list(l) do
-    raise(ArgumentError, message: "Unexpected list #{inspect l}")
+    raise ArgumentError, message: "Unexpected list #{inspect l}"
   end
 
   defp typespec(t, vars, caller) when is_tuple(t) do
diff --git a/lib/elixir/lib/protocol.ex b/lib/elixir/lib/protocol.ex
index fe390c3b03..84bd75c51f 100644
--- a/lib/elixir/lib/protocol.ex
+++ b/lib/elixir/lib/protocol.ex
@@ -276,6 +276,7 @@ defmodule Protocol.DSL do
   # We need to use :lists because Enum is not available yet
   require :lists, as: L
 
+  @doc false
   def args_and_body(module, name, arity) do
     # Generate arguments according the arity. The arguments
     # are named xa, xb and so forth. We cannot use string
@@ -304,6 +305,19 @@ defmodule Protocol.DSL do
     { args, body }
   end
 
+  @doc false
+  def callback_from_spec(module, name, arity) do
+    tuple = { name, arity }
+    specs = Module.get_attribute(module, :spec)
+
+    found = lc { k, v } inlist specs, k == tuple do
+      Kernel.Typespec.define_callback(module, tuple, v)
+      true
+    end
+
+    found != []
+  end
+
   defp conversions_for(module) do
     only   = Module.get_attribute(module, :only)
     except = Module.get_attribute(module, :except)
@@ -378,7 +392,7 @@ defmodule Protocol.DSL do
 
       # Convert the spec to callback if possible,
       # otherwise generate a dummy callback
-      Kernel.Typespec.callback_from_spec(__MODULE__, name, arity) ||
+      Protocol.DSL.callback_from_spec(__MODULE__, name, arity) ||
         @callback unquote(name)(unquote_splicing(type_args)), do: term
     end
   end
diff --git a/lib/elixir/src/elixir_module.erl b/lib/elixir/src/elixir_module.erl
index 88f02be41e..009997fb12 100644
--- a/lib/elixir/src/elixir_module.erl
+++ b/lib/elixir/src/elixir_module.erl
@@ -33,9 +33,6 @@ data_table(Module) ->
 docs_table(Module) ->
   ?ELIXIR_ATOM_CONCAT([o, Module]).
 
-spec_table(Module) ->
-  ?ELIXIR_ATOM_CONCAT([s, Module]).
-
 %% TRANSFORMATION FUNCTIONS
 
 %% Transformation of args and scope into a compiled erlang call.
@@ -87,7 +84,6 @@ compile(Line, Module, Block, Vars, #elixir_scope{} = S) when is_atom(Module) ->
   after
     ets:delete(data_table(Module)),
     ets:delete(docs_table(Module)),
-    ets:delete(spec_table(Module)),
     elixir_def:delete_table(Module),
     elixir_import:delete_table(Module)
   end;
@@ -130,10 +126,6 @@ build(Line, File, Module) ->
   DocsTable = docs_table(Module),
   ets:new(DocsTable, [ordered_set, named_table, public]),
 
-  %% Holds specs in a format it is easier to query.
-  SpecTable = spec_table(Module),
-  ets:new(SpecTable, [duplicate_bag, named_table, public]),
-
   %% We keep a separated table for function definitions
   %% and another one for imports. We keep them in different
   %% tables for organization and speed purpose (since the
diff --git a/lib/elixir/test/elixir/typespec_test.exs b/lib/elixir/test/elixir/typespec_test.exs
index 5e3cde716e..08287724fa 100644
--- a/lib/elixir/test/elixir/typespec_test.exs
+++ b/lib/elixir/test/elixir/typespec_test.exs
@@ -21,42 +21,42 @@ defmodule Typespec.Test.Type do
     spec = test_module do
       @type mytype
     end
-    assert {:type,{:mytype,{:type,_,:term,[]},[]}} = spec
+    assert {:mytype,{:type,_,:term,[]},[]} = spec
   end
 
   test "@type with a single type" do
     spec = test_module do
       @type mytype :: term
     end
-    assert {:type,{:mytype,{:type,_,:term,[]},[]}} = spec
+    assert {:mytype,{:type,_,:term,[]},[]} = spec
   end
 
   test "@type with an atom" do
     spec = test_module do
       @type mytype :: :atom
     end
-    assert {:type,{:mytype,{:atom,_,:atom},[]}} = spec
+    assert {:mytype,{:atom,_,:atom},[]} = spec
   end
 
   test "@type with an atom alias" do
     spec = test_module do
       @type mytype :: Atom
     end
-    assert {:type,{:mytype,{:atom,_,Atom},[]}} = spec
+    assert {:mytype,{:atom,_,Atom},[]} = spec
   end
 
   test "@type with an integer" do
     spec = test_module do
       @type mytype :: 10
     end
-    assert {:type,{:mytype,{:integer,_,10},[]}} = spec
+    assert {:mytype,{:integer,_,10},[]} = spec
   end
 
   test "@type with a negative integer" do
     spec = test_module do
       @type mytype :: -10
     end
-    assert {:type,{:mytype,{:op, _, :-, {:integer,_,10}},[]}} = spec
+    assert {:mytype,{:op, _, :-, {:integer,_,10}},[]} = spec
   end
 
   test "@type with a remote type" do
@@ -65,50 +65,50 @@ defmodule Typespec.Test.Type do
       t2 = @type mytype_arg :: Remote.type(integer)
       {t1, t2}
     end
-    assert {:type,{:mytype,{:remote_type, _, [{:atom, _, Remote.Some},{:atom, _, :type}, []]},[]}} = spec1
-    assert {:type,{:mytype_arg,{:remote_type, _, [{:atom, _, Remote},{:atom, _, :type},[{:type,_, :integer,[]}]]},[]}} = spec2
+    assert {:mytype,{:remote_type, _, [{:atom, _, Remote.Some},{:atom, _, :type}, []]},[]} = spec1
+    assert {:mytype_arg,{:remote_type, _, [{:atom, _, Remote},{:atom, _, :type},[{:type,_, :integer,[]}]]},[]} = spec2
   end
 
   test "@type with a binary" do
     spec = test_module do
       @type mytype :: binary
     end
-    assert {:type,{:mytype,{:type,_,:binary, []},[]}} = spec
+    assert {:mytype,{:type,_,:binary, []},[]} = spec
   end
 
   test "@type with an empty binary" do
     spec = test_module do
       @type mytype :: <<>>
     end
-    assert {:type,{:mytype,{:type,_,:binary, [{:integer, _, 0},{:integer, _, 0}]},[]}} = spec
+    assert {:mytype,{:type,_,:binary, [{:integer, _, 0},{:integer, _, 0}]},[]} = spec
   end
 
   test "@type with a binary with a base size" do
     spec = test_module do
       @type mytype :: <<_ :: 3>>
     end
-    assert {:type,{:mytype,{:type,_,:binary, [{:integer, _, 3},{:integer, _, 0}]},[]}} = spec
+    assert {:mytype,{:type,_,:binary, [{:integer, _, 3},{:integer, _, 0}]},[]} = spec
   end
 
   test "@type with a binary with a unit size" do
     spec = test_module do
       @type mytype :: <<_ :: _ * 8>>
     end
-    assert {:type,{:mytype,{:type,_,:binary, [{:integer, _, 0},{:integer, _, 8}]},[]}} = spec
+    assert {:mytype,{:type,_,:binary, [{:integer, _, 0},{:integer, _, 8}]},[]} = spec
   end
 
   test "@type with a range" do
     spec = test_module do
       @type mytype :: range(1,10)
     end
-    assert {:type,{:mytype,{:type,_,:range, [{:integer, _, 1},{:integer, _, 10}]},[]}} = spec
+    assert {:mytype,{:type,_,:range, [{:integer, _, 1},{:integer, _, 10}]},[]} = spec
   end
 
   test "@type with a range op" do
     spec = test_module do
       @type mytype :: 1..10
     end
-    assert {:type,{:mytype,{:type,_,:range, [{:integer, _, 1},{:integer, _, 10}]},[]}} = spec
+    assert {:mytype,{:type,_,:range, [{:integer, _, 1},{:integer, _, 10}]},[]} = spec
   end
 
   test "@type with a tuple" do
@@ -117,40 +117,40 @@ defmodule Typespec.Test.Type do
       t2 = @type mytype1 :: {}
       {t1, t2}
     end
-    assert {:type,{:mytype,{:type,_,:tuple, :any},[]}} = spec1
-    assert {:type,{:mytype1,{:type,_,:tuple, :any},[]}} = spec2
+    assert {:mytype,{:type,_,:tuple, :any},[]} = spec1
+    assert {:mytype1,{:type,_,:tuple, :any},[]} = spec2
   end
 
   test "@type with a fun" do
     spec = test_module do
       @type mytype :: fun
     end
-    assert {:type,{:mytype,{:type,_,:fun, []},[]}} = spec
+    assert {:mytype,{:type,_,:fun, []},[]} = spec
   end
 
   test "@type with a fun with arguments and return type" do
     spec = test_module do
       @type mytype :: fun(integer, integer, do: integer)
     end
-    assert {:type,{:mytype,{:type,_,:fun, [{:type, _, :product,
-                         [{:type, _, :integer, []}, {:type, _, :integer, []}]},
-                         {:type, _, :integer, []}]},[]}} = spec
+    assert {:mytype,{:type,_,:fun, [{:type, _, :product,
+             [{:type, _, :integer, []}, {:type, _, :integer, []}]},
+             {:type, _, :integer, []}]},[]} = spec
   end
 
   test "@type with a fun with no arguments and return type" do
     spec = test_module do
       @type mytype :: fun(do: integer)
     end
-    assert {:type,{:mytype,{:type,_,:fun, [{:type, _, :product, []},
-                         {:type, _, :integer, []}]}, []}} = spec
+    assert {:mytype,{:type,_,:fun, [{:type, _, :product, []},
+             {:type, _, :integer, []}]}, []} = spec
   end
 
   test "@type with a fun with any arity and return type" do
     spec = test_module do
       @type mytype :: fun(..., do: integer)
     end
-    assert {:type,{:mytype,{:type,_,:fun, [{:type, _, :any},
-                         {:type, _, :integer, []}]}, []}} = spec
+    assert {:mytype,{:type,_,:fun, [{:type, _, :any},
+             {:type, _, :integer, []}]}, []} = spec
   end
 
   test "@type with a union" do
@@ -158,17 +158,17 @@ defmodule Typespec.Test.Type do
       @type mytype :: integer | char_list
                     | atom
     end
-    assert {:type,{:mytype,{:type,_,:union, [{:type, _, :integer, []},
-                         {:remote_type, _, [{:atom, _, :elixir},{:atom, _, :char_list}, []]},
-                         {:type, _, :atom, []}]}, []}} = spec
+    assert {:mytype,{:type,_,:union, [{:type, _, :integer, []},
+             {:remote_type, _, [{:atom, _, :elixir},{:atom, _, :char_list}, []]},
+             {:type, _, :atom, []}]}, []} = spec
   end
 
   test "@type with an access macro" do
     spec = test_module do
       @type mytype :: Range[first: integer]
     end
-    assert {:type,{:mytype,{:type, _, :tuple,
-              [{:atom, _, Range}, {:type, _, :integer, []}, {:type, _, :any, []}]}, []}} = spec
+    assert {:mytype,{:type, _, :tuple,
+             [{:atom, _, Range}, {:type, _, :integer, []}, {:type, _, :any, []}]}, []} = spec
   end
 
   test "@type with parameters" do
@@ -178,9 +178,9 @@ defmodule Typespec.Test.Type do
       t3 = @type mytype2(x,y) :: {x,y}
       {t1,t2,t3}
     end
-    assert {:type,{:mytype,{:var,_,:x},[{:var,_,:x}]}} = spec1
-    assert {:type,{:mytype1,{:type,_,:list,[{:var,_,:x}]},[{:var,_,:x}]}} = spec2
-    assert {:type,{:mytype2,{:type,_,:tuple,[{:var,_,:x},{:var,_,:y}]},[{:var,_,:x},{:var, _, :y}]}} = spec3
+    assert {:mytype,{:var,_,:x},[{:var,_,:x}]} = spec1
+    assert {:mytype1,{:type,_,:list,[{:var,_,:x}]},[{:var,_,:x}]} = spec2
+    assert {:mytype2,{:type,_,:tuple,[{:var,_,:x},{:var,_,:y}]},[{:var,_,:x},{:var, _, :y}]} = spec3
   end
 
   test "@type with annotations" do
@@ -189,15 +189,15 @@ defmodule Typespec.Test.Type do
       t2 = @type mytype1 :: fun(a :: integer, do: integer)
       {t1,t2}
     end
-    assert {:type, {:mytype, {:ann_type, _, [{:var, _, :named}, {:type, _, :integer, []}]}, []}} = spec1
-    assert {:type, {:mytype1,{:type,_,:fun,[{:type,_,:product,[{:ann_type,_,[{:var,_,:a},{:type,_,:integer,[]}]}]},{:type,_,:integer,[]}]},[]}} = spec2
+    assert {:mytype, {:ann_type, _, [{:var, _, :named}, {:type, _, :integer, []}]}, []} = spec1
+    assert {:mytype1,{:type,_,:fun,[{:type,_,:product,[{:ann_type,_,[{:var,_,:a},{:type,_,:integer,[]}]}]},{:type,_,:integer,[]}]},[]} = spec2
   end
 
   test "@opaque(type)" do
     spec = test_module do
       @opaque mytype(x) :: x
     end
-    assert {:opaque,{:mytype,{:var,_,:x},[{:var,_,:x}]}} = spec
+    assert {:mytype,{:var,_,:x},[{:var,_,:x}]} = spec
   end
 
   test "@type + opaque" do
@@ -267,27 +267,10 @@ defmodule Typespec.Test.Type do
     ] = List.sort(specs)
   end
 
-  test "defines a callback from a spec" do
-    callbacks = test_module do
-      def myfun(x), do: x
-      @spec myfun(integer), do: integer
-      @spec myfun(char_list),  do: char_list
-      Kernel.Typespec.callback_from_spec(__MODULE__, :myfun, 1)
-      @callback
-    end
+  # Conversion to AST
 
-    assert [
-      { {:myfun,1}, {:type,_,:fun,[{:type,_,:product,[{:type,_,:integer,[]}]},{:type,_,:integer,[]}]} },
-      { {:myfun,1}, {:type,_,:fun,[{:type,_,:product,[
-                      {:remote_type, _, [{:atom, _, :elixir},{:atom, _, :char_list}, []]}]},
-                      {:remote_type, _, [{:atom, _, :elixir},{:atom, _, :char_list}, []]}]} }
-    ] = List.sort(callbacks)
-  end
-
-  # to_binary
-
-  test "to_binary types" do
-    types = [
+  test "type_to_ast" do
+    quoted = [
       (quote do: @type with_ann() :: (t :: atom())),
       (quote do: @type empty_tuple_type() :: {}),    
       (quote do: @type imm_type_1() :: 1),
@@ -302,19 +285,20 @@ defmodule Typespec.Test.Type do
       (quote do: @type ftype() :: fun() | fun(do: integer()) | fun(integer(), do: integer())),
     ]
 
-    spec = test_module do
-      Module.eval_quoted __MODULE__, quote do: unquote_splicing(types)
+    types = test_module do
+      Module.eval_quoted __MODULE__, quote do: unquote_splicing(quoted)
       @type ++ @opaque
     end
 
-    spec = Enum.reverse(spec)
+    types = Enum.reverse(types)
 
-    lc { typespec, definition } inlist Enum.zip(spec, types) do
-      assert Kernel.Typespec.to_binary({ :type, typespec }) == Macro.to_binary(definition)
+    lc { type, definition } inlist Enum.zip(types, quoted) do
+      ast = Kernel.Typespec.type_to_ast(type)
+      assert Macro.to_binary(quote do: @type unquote(ast)) == Macro.to_binary(definition)
     end
   end
 
-  test "to_binary spec" do
+  test "spec_to_ast" do
     specs = [
       (quote do: @spec a(), do: integer()),
       (quote do: @spec a(atom()), do: integer()),
@@ -327,28 +311,34 @@ defmodule Typespec.Test.Type do
       Enum.reverse @spec
     end
 
-    lc { { tuple, spec }, definition } inlist Enum.zip(compiled, specs) do
-      assert Kernel.Typespec.to_binary({ { :spec, tuple }, [spec] }) == Macro.to_binary(definition)
+    lc { { { name, _ }, spec }, definition } inlist Enum.zip(compiled, specs) do
+      { args, result } = Kernel.Typespec.spec_to_ast(spec)
+      quoted = quote do: @spec unquote(name)(unquote_splicing(args)), do: unquote(result)
+      assert Macro.to_binary(quoted) == Macro.to_binary(definition)
     end
   end
 
-  # test/spec retrieval
+  # types/specs retrieval
 
   test "specs retrieval" do
     Code.compiler_options debug_info: true
+
     { :module, T, binary, _ } = defmodule T do
       @spec a, do: any
-      def a, do: nil
+      def a,   do: nil
     end
-    Code.compiler_options debug_info: false
+
     :code.delete(T)
     :code.purge(T)
-    assert [{{:spec,{:a,_}},[{:type,_,:fun,[{:type,_,:product,[]},{:type,_,:any,[]}]}]}] = Kernel.Typespec.specs(binary)
-    assert [{{:spec,{:a,_}},[{:type,_,:fun,[{:type,_,:product,[]},{:type,_,:any,[]}]}]}] = Kernel.Typespec.specs(binary, :a, 0)
+
+    assert [{{:a,_},[{:type,_,:fun,[{:type,_,:product,[]},{:type,_,:any,[]}]}]}] = Kernel.Typespec.beam_specs(binary)
+  after
+    Code.compiler_options debug_info: false
   end
 
   test "types retrieval" do
     Code.compiler_options debug_info: true
+
     { :module, T, binary, _ } = defmodule T do
       @type a :: any
       @typep b :: any
@@ -357,23 +347,15 @@ defmodule Typespec.Test.Type do
       @opaque c :: any
     end
 
-    assert [
-            {:opaque, {:c,{:type,_,:any,[]},[]}},
-            {:type, {:a,{:type,_,:any,[]},[]}},
-            {:typep, {:b,{:type,_,:any,[]},[]}},
-           ] = Kernel.Typespec.types(binary)
-    assert [
-            {:type, {:a,{:type,_,:any,[]},[]}},
-           ] = Kernel.Typespec.types(binary, :a, 0)
-    assert [
-            {:typep, {:b,{:type,_,:any,[]},[]}},
-           ] = Kernel.Typespec.types(binary, :b, 0)
-    assert [
-            {:opaque, {:c,{:type,_,:any,[]},[]}},
-           ] = Kernel.Typespec.types(binary, :c, 0)
-  after
-    Code.compiler_options debug_info: false
     :code.delete(T)
     :code.purge(T)
+
+    assert [
+      {:opaque, {:c,{:type,_,:any,[]},[]}},
+      {:type, {:a,{:type,_,:any,[]},[]}},
+      {:typep, {:b,{:type,_,:any,[]},[]}},
+    ] = Kernel.Typespec.beam_types(binary)
+  after
+    Code.compiler_options debug_info: false
   end
 end
\ No newline at end of file
diff --git a/lib/iex/lib/iex/helpers.ex b/lib/iex/lib/iex/helpers.ex
index b8027feba9..5d67187f8b 100644
--- a/lib/iex/lib/iex/helpers.ex
+++ b/lib/iex/lib/iex/helpers.ex
@@ -13,7 +13,8 @@ defmodule IEx.Helpers do
 
   * `c/2` - compiles a file in the given path
   * `h/0`,`h/1`, `h/2` - prints help/documentation
-  * `t/1`,`t/3` — prints type specification information
+  * `t/1` — prints types information
+  * `s/1`, `s/3` — prints specs information
   * `m/0` - prints loaded modules
   * `r/0` - recompiles and reloads the given module's source file
   * `v/0` - prints all commands and values
@@ -214,69 +215,91 @@ defmodule IEx.Helpers do
     atom_to_binary(var)
   end
 
-  # FIXME: this can't be shown as h(t/1)
   @doc """
-  Prints all types and function specifications from a given module
+  Prints all types for the given module
 
   ## Examples
 
-    t(Enum)
-
-  """  
-  def __t_module__(module) do
-    types =
-    lc type inlist Kernel.Typespec.types(module) do
-      IO.puts Kernel.Typespec.to_binary(type)
-      type
-    end
-    specs =
-    lc spec inlist Kernel.Typespec.specs(module) do
-      IO.puts Kernel.Typespec.to_binary(spec)
-      spec
-    end
-    if specs == [] and types == [] do
-      IO.puts "No type specifications for #{inspect module} has been found"
-    end        
-    :ok  
-  end
-
-  @doc """
-  Prints the type specification for a given function or a type
-
-  ## Examples
-
-      t(Enum.all?/2)
-      t(Enum.t/0)
+      t(Enum)
 
   """
-  def t(module, function, arity) do
-    types =
-    lc type inlist Kernel.Typespec.types(module, function, arity) do
-      IO.puts Kernel.Typespec.to_binary(type)
-      type
+  def t(module) do
+    types = lc type inlist Kernel.Typespec.beam_types(module), do: print_type(type)
+
+    if types == [] do
+      IO.puts "No types for #{inspect module} has been found"
     end
-    specs =
-    lc spec inlist Kernel.Typespec.specs(module, function, arity) do
-      IO.puts Kernel.Typespec.to_binary(spec)
-      spec
-    end
-    if specs == [] and types == [] do
-      IO.puts "No type specification for #{inspect module}.#{function}/#{arity} has been found"
-    end        
+
     :ok
   end
 
-  defmacro t({ :/, _, [{ { :., _, [mod, fun] }, _, [] }, arity] }) do
+  @doc """
+  Prints all specs from a given module.
+
+  ## Examples
+
+      s(Enum)
+
+  """
+  defmacro s({ :/, _, [{ { :., _, [mod, fun] }, _, [] }, arity] }) do
     quote do
-      t(unquote(mod), unquote(fun), unquote(arity))
-    end
-  end
-  defmacro t(module) do
-    quote do
-      __t_module__(unquote(module))
+      s(unquote(mod), unquote(fun), unquote(arity))
     end
   end
 
+  defmacro s(module) do
+    quote do
+      s(unquote(module), :all)
+    end
+  end
+
+  @doc false
+  def s(module, :all) do
+    specs = lc spec inlist Kernel.Typespec.beam_specs(module), do: print_spec(spec)
+
+    if specs == [] do
+      IO.puts "No specs for #{inspect module} has been found"
+    end
+
+    :ok
+  end
+
+  @doc """
+  Prints the specs for a given function.
+
+  ## Examples
+
+      s(Enum.all?/2)
+      s(Enum.t/0)
+
+  """
+  def s(module, function, arity) do
+    spec = List.keyfind(Kernel.Typespec.beam_specs(module), { function, arity }, 0)
+
+    if spec do
+      print_spec(spec)
+    else
+      IO.puts "No spec for #{inspect module}.#{function}/#{arity} has been found"
+    end
+
+    :ok
+  end
+
+  defp print_type({ kind, type }) do
+    ast = Kernel.Typespec.type_to_ast(type)
+    IO.puts "@#{kind} #{Macro.to_binary(ast)}"
+    true
+  end
+
+  defp print_spec({ { name, _arity }, specs }) do
+    Enum.each specs, fn(spec) ->
+      { args, result } = Kernel.Typespec.spec_to_ast(spec)
+      bin_args   = Macro.to_binary { name, 0, args }
+      bin_result = Macro.to_binary result
+      IO.puts "@spec #{bin_args}, do: #{bin_result}"
+    end
+    true
+  end
 
   @doc """
   Retrieves nth query's value from the history. Use negative