add Cluster struct

README.md

@@ -1,4 +1,4 @@
-# Rock
+# ROCK
 [![Build Status](https://semaphoreci.com/api/v1/ayrat555/rock/branches/master/badge.svg)](https://semaphoreci.com/ayrat555/rock)
 
 ROCK: A Robust Clustering Algorithm for Categorical Attributes

lib/rock/struct/cluster.ex

@@ -0,0 +1,18 @@
+defmodule Rock.Struct.Cluster do
+  defstruct points: [], size: 0
+
+  alias Rock.Struct.Cluster
+  alias Rock.Struct.Point
+
+  def new(points) when is_list(points) do
+    size = points |> Enum.count
+
+    %Cluster{points: points, size: size}
+  end
+
+  def add_point(%Cluster{points: points, size: size}, %Point{} = point) do
+    new_points = points ++ [point]
+
+    %Cluster{points: new_points, size: size + 1}
+  end
+end

mix.exs

@@ -7,7 +7,9 @@ defmodule Rock.Mixfile do
      elixir: "~> 1.4",
      build_embedded: Mix.env == :prod,
      start_permanent: Mix.env == :prod,
-     deps: deps()]
+     deps: deps(),
+     elixirc_paths: elixirc_paths(Mix.env)
+    ]
   end
 
   def application do
@@ -19,4 +21,7 @@ defmodule Rock.Mixfile do
       {:credo, "~> 0.7", only: [:dev, :test]}
     ]
   end
+
+  defp elixirc_paths(:test), do: ["lib", "test/support"]
+  defp elixirc_paths(_), do: ["lib"]
 end

test/rock/struct/cluster_test.exs

@@ -0,0 +1,23 @@
+defmodule Rock.Struct.ClusterTest do
+  use ExUnit.Case
+  alias Rock.Struct.Cluster
+  alias Rock.Test.TestFactory
+
+  test "adds a point to a cluster" do
+    point = TestFactory.from_string(:point, ["6"])
+    cluster = TestFactory.from_string(:cluster,
+      [
+        ["1", "2", "3"],
+        ["5"]
+      ])
+
+    %Cluster{points: points, size: size} =
+      cluster
+      |> Cluster.add_point(point)
+
+    ^size = 3
+    assert Enum.any?(points, fn(p) ->
+      p == point
+    end)
+  end
+end

test/support/test_factory.ex

@@ -0,0 +1,16 @@
+defmodule Rock.Test.TestFactory do
+  alias Rock.Struct.Point
+  alias Rock.Struct.Cluster
+
+  def from_string(:cluster, string_points) do
+    string_points
+    |> Enum.map(fn(string_point) ->
+      from_string(:point, string_point)
+    end)
+    |> Cluster.new
+  end
+
+  def from_string(:point, string_attributes) do
+    string_attributes |> Point.new
+  end
+end