[#5] – Refactor some modules to better project organization

lib/ex_shards.ex

@@ -47,22 +47,22 @@ defmodule ExShards do
     * [API Reference](http://cabol.github.io/shards)
   """
 
-  use ExShards.API
-
-  @type tab :: atom
-  @type key :: term
-  @type value :: term
-  @type state :: ExShards.State.t
+  use ExShards.Construct
 
   ## API
 
-  construct :shards, exclude_all: [:start, :stop], exclude: [new: 2]
+  inject :shards, except: [:start, :stop, new: 2]
 
   @doc false
   def new(tab, opts \\ []), do: :shards.new(tab, opts)
 
   ## Extended API
 
+  @type tab :: atom
+  @type key :: term
+  @type value :: term
+  @type state :: ExShards.State.t
+
   @spec drop(tab, Enumerable.t) :: map
   def drop(tab, keys), do: call(tab, :drop, [tab, keys])
 

lib/ex_shards/construct.ex

@@ -0,0 +1,84 @@
+defmodule ExShards.Construct do
+  @moduledoc """
+  This is an utility module, which provides a set of macros to
+  inject functions from Erlang modules.
+  """
+
+  @doc false
+  defmacro __using__(_opts) do
+    quote do
+      @before_compile unquote(__MODULE__)
+
+      import unquote(__MODULE__)
+    end
+  end
+
+  @doc false
+  defmacro __before_compile__(_env) do
+    quote do
+      @public_defs Module.definitions_in(__MODULE__, :def)
+
+      def definitions, do: @public_defs
+    end
+  end
+
+  @doc """
+  Injects exported functions from an Erlang module.
+
+  By default, it injects all functions from the given module:
+
+      inject :lists
+
+  Alternatively, it allows you to pass pairs of name/arities to `:except`
+  as a fine grained control on what to inject (or not):
+
+      inject :lists, except: [append: 1]
+
+  Besides, it allows you to pass only the name of the fuction(s) to `:except`,
+  in order to exclude all function that matches with that name – no matter
+  the arity. E.g.:
+
+      inject :lists, except: [:append]
+
+  This will exclude either `:lists.append/1` and `:lists.append/2`.
+
+  ## Example
+
+      defmodule Utils do
+        use ExShards.Construct
+
+        # injects all exported functions in module `:lists`
+        inject :lists
+
+        # injects all exported functions in module `:maps` except:
+        # `:maps.get/2`, `:maps.get/3` and `:maps.find/2`.
+        inject :maps, except: [:get, find: 2]
+      end
+  """
+  defmacro inject(mod, opts \\ []) do
+    # build public function list
+    public_defs = opts
+    |> Keyword.get(:except, [])
+    |> :lists.append([:module_info])
+    |> Enum.reduce(mod.module_info(:exports), fn
+      ({k, v}, acc) -> Keyword.delete(acc, k, v)
+      (k, acc)      -> Keyword.delete(acc, k)
+    end)
+
+    # generate definitions
+    for {fun, arity} <- public_defs do
+      args = if arity > 0 do
+        1..arity
+        |> Enum.map(&(Module.concat(["arg#{&1}"])))
+        |> Enum.map(fn(x) -> {x, [], __MODULE__} end)
+      else
+        []
+      end
+      quote do
+        def unquote(fun)(unquote_splicing(args)) do
+          unquote(mod).unquote(fun)(unquote_splicing(args))
+        end
+      end
+    end
+  end
+end

lib/ex_shards/dist.ex

@@ -82,10 +82,11 @@ defmodule ExShards.Dist do
     * [API Reference](http://cabol.github.io/shards)
   """
 
-  use ExShards.API
-  #use ExShards.API.Ext
+  use ExShards.Construct
+  #use ExShards.Ext
 
-  construct :shards_dist, exclude: [new: 2]
+  inject :shards_dist, except: [new: 2]
 
+  @doc false
   def new(tab, opts \\ []), do: :shards_dist.new(tab, opts)
 end

lib/ex_shards/api/ext.ex → lib/ex_shards/ext.ex

@@ -1,4 +1,4 @@
-defmodule ExShards.API.Ext do
+defmodule ExShards.Ext do
   @moduledoc """
   This module extends the Shards API providing some extra functions.
 
@@ -43,7 +43,7 @@ defmodule ExShards.API.Ext do
   @doc false
   defmacro __using__(_opts) do
     quote do
-      @behaviour ExShards.API.Ext
+      @behaviour ExShards.Ext
 
       def drop(tab, keys, state \\ ExShards.State.new) do
         Enum.reduce(keys, %{}, fn(key, acc) ->

lib/ex_shards/local.ex

@@ -32,10 +32,11 @@ defmodule ExShards.Local do
     * [API Reference](http://cabol.github.io/shards)
   """
 
-  use ExShards.API
-  use ExShards.API.Ext
+  use ExShards.Construct
+  use ExShards.Ext
 
-  construct :shards_local, exclude: [new: 2]
+  inject :shards_local, except: [new: 2]
 
+  @doc false
   def new(tab, opts \\ []), do: :shards_local.new(tab, opts)
 end

lib/ex_shards/state.ex

@@ -3,7 +3,8 @@ defmodule ExShards.State do
   Shards State.
 
   This module overrides the original `shards_state` getter and setter
-  functions in order to make them more pipe-operator friendly.
+  functions in order to make them more Elixir-friendly – e.g.: take
+  advantage of pipe-operator.
 
   ## Examples
 
@@ -18,7 +19,7 @@ defmodule ExShards.State do
     * [Shards](https://github.com/cabol/shards/blob/master/src/shards_state.erl)
   """
 
-  use ExShards.API
+  use ExShards.Construct
 
   require Record
 
@@ -41,29 +42,29 @@ defmodule ExShards.State do
     pick_shard_fun: pick_fun,
     pick_node_fun: pick_fun])
 
-  construct :shards_state,
-    exclude: [
+  inject :shards_state,
+    except: [
       module: 2,
       n_shards: 2,
       pick_shard_fun: 2,
       pick_node_fun: 2]
 
-  @doc false
+  @spec module(t, module) :: t
   def module(state, module) do
     :shards_state.module(module, state)
   end
 
-  @doc false
+  @spec n_shards(t, integer) :: t
   def n_shards(state, n_shards) do
     :shards_state.n_shards(n_shards, state)
   end
 
-  @doc false
+  @spec pick_shard_fun(t, pick_fun) :: t
   def pick_shard_fun(state, pick_shard_fun) do
     :shards_state.pick_shard_fun(pick_shard_fun, state)
   end
 
-  @doc false
+  @spec pick_node_fun(t, pick_fun) :: t
   def pick_node_fun(state, pick_node_fun) do
     :shards_state.pick_node_fun(pick_node_fun, state)
   end

mix.exs

@@ -3,11 +3,13 @@ defmodule ExShards.Mixfile do
 
   def project do
     [app: :ex_shards,
-     version: "0.1.0",
+     version: "0.2.0",
      elixir: "~> 1.2",
      build_embedded: Mix.env == :prod,
      start_permanent: Mix.env == :prod,
      deps: deps(),
+     test_coverage: [tool: ExCoveralls],
+     preferred_cli_env: ["coveralls": :test, "coveralls.detail": :test, "coveralls.post": :test, "coveralls.html": :test],
      package: package(),
      description: "ExShards – Elixir Wrapper for cabol/shards"]
   end
@@ -19,7 +21,8 @@ defmodule ExShards.Mixfile do
   defp deps do
     [{:shards, "~> 0.4"},
      {:ex2ms, "~> 1.4"},
-     {:ex_doc, ">= 0.0.0", only: :dev}]
+     {:ex_doc, ">= 0.0.0", only: :dev},
+     {:excoveralls, "~> 0.6.2", only: :test}]
   end
 
   defp package do

mix.lock

@@ -1,4 +1,13 @@
-%{"earmark": {:hex, :earmark, "1.1.1", "433136b7f2e99cde88b745b3a0cfc3fbc81fe58b918a09b40fce7f00db4d8187", [:mix], []},
+%{"certifi": {:hex, :certifi, "0.7.0", "861a57f3808f7eb0c2d1802afeaae0fa5de813b0df0979153cbafcd853ababaf", [:rebar3], []},
+  "earmark": {:hex, :earmark, "1.1.1", "433136b7f2e99cde88b745b3a0cfc3fbc81fe58b918a09b40fce7f00db4d8187", [:mix], []},
   "ex2ms": {:hex, :ex2ms, "1.4.0", "e43b410888b45ba363ea6650db3736db3e455a0a412ec244ac633fede857bcb2", [:mix], []},
   "ex_doc": {:hex, :ex_doc, "0.14.5", "c0433c8117e948404d93ca69411dd575ec6be39b47802e81ca8d91017a0cf83c", [:mix], [{:earmark, "~> 1.0", [hex: :earmark, optional: false]}]},
-  "shards": {:hex, :shards, "0.4.0", "456f0ed35a30aae2bd7c5b8e565d2008c45f82f0ef06e5927a3d9267b0a20a19", [:make, :rebar3], []}}
+  "excoveralls": {:hex, :excoveralls, "0.6.2", "0e993d096f1fbb6e70a3daced5c89aac066bda6bce57829622aa2d1e2b338cfb", [:mix], [{:exjsx, "~> 3.0", [hex: :exjsx, optional: false]}, {:hackney, ">= 0.12.0", [hex: :hackney, optional: false]}]},
+  "exjsx": {:hex, :exjsx, "3.2.1", "1bc5bf1e4fd249104178f0885030bcd75a4526f4d2a1e976f4b428d347614f0f", [:mix], [{:jsx, "~> 2.8.0", [hex: :jsx, optional: false]}]},
+  "hackney": {:hex, :hackney, "1.6.5", "8c025ee397ac94a184b0743c73b33b96465e85f90a02e210e86df6cbafaa5065", [:rebar3], [{:certifi, "0.7.0", [hex: :certifi, optional: false]}, {:idna, "1.2.0", [hex: :idna, optional: false]}, {:metrics, "1.0.1", [hex: :metrics, optional: false]}, {:mimerl, "1.0.2", [hex: :mimerl, optional: false]}, {:ssl_verify_fun, "1.1.1", [hex: :ssl_verify_fun, optional: false]}]},
+  "idna": {:hex, :idna, "1.2.0", "ac62ee99da068f43c50dc69acf700e03a62a348360126260e87f2b54eced86b2", [:rebar3], []},
+  "jsx": {:hex, :jsx, "2.8.2", "7acc7d785b5abe8a6e9adbde926a24e481f29956dd8b4df49e3e4e7bcc92a018", [:mix, :rebar3], []},
+  "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], []},
+  "mimerl": {:hex, :mimerl, "1.0.2", "993f9b0e084083405ed8252b99460c4f0563e41729ab42d9074fd5e52439be88", [:rebar3], []},
+  "shards": {:hex, :shards, "0.4.0", "456f0ed35a30aae2bd7c5b8e565d2008c45f82f0ef06e5927a3d9267b0a20a19", [:make, :rebar3], []},
+  "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.1", "28a4d65b7f59893bc2c7de786dec1e1555bd742d336043fe644ae956c3497fbe", [:make, :rebar], []}}