Byebug… i don’t know how much it can do, because I found Pry much superior in Ruby world, and there is Pry in Elixir world too, anyway, here’s little article that I think will be helpful Debugging techniques in Elixir « Plataformatec Blog

Not sure about other text editors, but in spacemacs with alchemist it’s possible to send snippets of code from a buffer into the repl, so I use that sometimes. Although most often I just edit and save the module’s source code and rely on code reloading (with exsync, for example) to also update the loaded modules in the repl.

For “debugging” I tend to use tracing, like rexbug. I haven’t found a way to do step-through debugging sensibly with elixir …

iex(2)> Enum.map([1,2,3], fn a ->
...(2)>   IO.puts a
...(2)>   a * a
...(2)> end)

Just writing them out as you would do in an editor is sufficient.

It would work for a comnprehension as well, just hit enter after do (no cologn!).

I have no clue what Byebug is, so can’t help you with that.