1 files changed, 19 insertions, 0 deletions
diff --git a/lib/util/stream.ex b/lib/util/stream.ex
new file mode 100644
index 0000000..b143bc1
--- /dev/null
+++ b/lib/util/stream.ex
@@ -0,0 +1,19 @@
+defmodule Thulani.Util.Stream do
+  def take_until(enum, fun) when :erlang.is_function(fun, 1) do
+    lazy(enum, fn f1 ->
+      fn entry, acc ->
+        if(fun.(entry)) do
+          {:cont, result} = f1.(entry, acc)
+          {:halt, result}
+        else
+          f1.(entry, acc)
+        end
+      end
+    end)
+  end
+
+  @compile {:inline, lazy: 2}
+
+  defp lazy(%Stream{done: nil, funs: funs} = lazy, fun), do: %{lazy | funs: [fun | funs]}
+  defp lazy(enum, fun), do: %Stream{enum: enum, funs: [fun]}
+end