Example compile-time dependency adapter and assertions

ash_sat_solver.ex

defmodule Ash.SAT.Solver.Behaviour do
  @callback function(:input) :: :return
end

cond do
  
  {:module, Picosat} = Code.ensure_loaded(Picosat) ->
    defmodule Ash.SAT.Solver do
      @behaviour Ash.SAT.Solver.Behaviour
      def function(:input), do: :picsat_specific
    end
  
  {:module, Csp} = Code.ensure_loaded(Csp) ->
    IO.warn(
      "using in-effecient Csp fallback,
      helpful instructions here"
    )
    
    defmodule Ash.SAT.Solver do
      @behaviour Ash.SAT.Solver.Behaviour
      def function(:input), do: :csp_specific
    end
    
    {:error, :nofile} ->
      raise CompileError, 
        "no SAT solver dependency installed,
        helpful instructions here"
end