Parse eprof result and create a CSV out of it

eprof_to_csv.ex

# eprof_results is the output printed by the `eprof` profiler
# with the "extra" lines already stripped (e.g. "Profile done over XXX matching functions")

eprof_results
|> String.split("\n", trim: true)
|> Enum.map(fn
  "anonymous fn" <> _rest = row ->
    [anonymous_fn, rest] =
      String.split(row, ~r{anonymous fn/\d+ in .*/\d+}, trim: true, include_captures: true)
    [anonymous_fn] ++ String.split(rest, ~r/\s/, trim: true)
    
  row ->
    String.split(row, ~r/\s/, trim: true)
end)
|> Enum.map(& Enum.join(&1, ", "))
|> Enum.join("\n")
|> then(& File.write!("results.csv", &1))