Simulate Regex match guards in functions

Questions / Help
7

Thanks! Now it looks great, succinct and very maintainable, as there is no need to keep the atoms synced between message_types and the functions.

Here’s the final code with the correct syntax, using Kernel.apply/3 as suggested by @Qqwy

defmodule Test do
  @message_types [
    {~r/hi/, :fn_hi},
    {~r/bye/, :fn_bye}
  ]

  def reply(msg) do
    {_, func} = Enum.find(@message_types,
                          {nil, :fn_unknown},
                          fn {reg, _} -> String.match?(msg, reg) end
                         )
    Kernel.apply(Test, func, [msg])
  end

  def fn_hi(msg), do: "Hello! you said " <> msg
  def fn_bye(msg), do: "Bye! you said " <> msg
  def fn_unknown(msg), do: "I didn't understand you. You said: " <> msg

end

To test it:

$ iex -r test.ex 
Erlang/OTP 18 [erts-7.3] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false] [dtrace]

Interactive Elixir (1.2.5) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> Test.reply("hi")
"Hello! you said hi"
iex(2)> Test.reply("ok bye!")
"Bye! you said ok bye!"
iex(3)> Test.reply("other")  
"I didn't understand you. You said: other"
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