I'm trying to write Ruby's inject method in Elixir.

gistfile1.ex

 defmodule Foo do
   def bar(acc, [H | T]) do
     acc + H + bar(T)
   end

   def bar(acc, []) do
     acc
   end
 end

Foo.bar(7, [1, 2, 3])

** (FunctionClauseError) no function clause matching: Foo.bar(7, [1,2,3])
    iex:110: Foo.bar(7, [1,2,3])
    erl_eval.erl:569: :erl_eval.do_apply/6
    src/elixir.erl:133: :elixir.eval_forms/3
    /private/tmp/elixir-Zrrr/elixir-lang-elixir-90ff71b/lib/iex/lib/iex/server.ex:19: IEx.Server.do_loop/1