allow floats as weights

lib/edge.ex

@@ -48,7 +48,7 @@ defmodule Graph.Edge do
     label = Keyword.get(opts, :label)
     weight = Keyword.get(opts, :weight, 1)
     case {label, weight} do
-      {_, w} = meta when is_integer(w) ->
+      {_, w} = meta when is_integer(w) or is_float(w) ->
         meta
       {_, _} ->
         raise ArgumentError, message: "invalid value for :weight, must be an integer"

lib/priority_queue.ex

@@ -42,18 +42,18 @@ defmodule PriorityQueue do
       {:value, :bar}
   """
   @spec push(t, term, integer) :: t
-  def push(%__MODULE__{priorities: {size, _} = tree} = pq, term, priority) when is_integer(priority) and size > 0 do
+  def push(%__MODULE__{priorities: {size, _} = tree} = pq, term, priority) when (is_integer(priority) or is_float(priority)) and size > 0 do
     case :gb_trees.lookup(priority, tree) do
       :none ->
         %__MODULE__{pq | priorities: :gb_trees.insert(priority, :queue.in(term, :queue.new), tree)}
       {:value, q} ->
         %__MODULE__{pq | priorities: :gb_trees.update(priority, :queue.in(term, q), tree)}
     end
   end
-  def push(%__MODULE__{priorities: {0, _} = tree} = pq, term, priority) when is_integer(priority) do
+  def push(%__MODULE__{priorities: {0, _} = tree} = pq, term, priority) when is_integer(priority) or is_float(priority) do
     %__MODULE__{pq | priorities: :gb_trees.insert(priority, :queue.in(term, :queue.new), tree)}
   end
-  def push(%__MODULE__{priorities: nil} = pq, term, priority) when is_integer(priority) do
+  def push(%__MODULE__{priorities: nil} = pq, term, priority) when is_integer(priority) or is_float(priority) do
     %__MODULE__{pq | priorities: :gb_trees.insert(priority, :queue.in(term, :queue.new), :gb_trees.empty)}
   end
 

test/graph_test.exs

@@ -35,9 +35,13 @@ defmodule GraphTest do
     assert "#Graph<type: directed, num_vertices: 151, num_edges: 150>" = str
   end
 
+  test "graph with float weights" do
+    g = build_floatweight_graph()
+    assert %{type: :directed} = Graph.info(g)
+  end
+
   test "get info about graph" do
     g = build_basic_cyclic_graph()
-
     assert %{type: :directed, num_vertices: 5, num_edges: 7} = Graph.info(g)
   end
 
@@ -143,6 +147,12 @@ defmodule GraphTest do
     assert ^shortest_len = length(shortest_g)
   end
 
+  test "shortest path for floatweight graph" do
+    g = build_floatweight_graph()
+    shortest_g = Graph.dijkstra(g, :a, :d)
+    assert shortest_g == [:a, :b, :c, :d]
+  end
+
   test "shortest path for complex graph" do
     g = build_complex_graph()
 
@@ -287,6 +297,14 @@ defmodule GraphTest do
     assert 20 = Graph.degeneracy(g)
   end
 
+  defp build_floatweight_graph do
+    Graph.new
+    |> Graph.add_edge(:a, :b, weight: 0.1)
+    |> Graph.add_edge(:b, :c, weight: 0.1)
+    |> Graph.add_edge(:c, :d, weight: 0.1)
+    |> Graph.add_edge(:a, :d, weight: 0.3000001)
+  end
+
   defp build_basic_cyclic_graph do
     Graph.new
     |> Graph.add_vertex(:a)