Not much, I dit not reach for Ecto intentionally.. which I would have done if it was production code. 
The most interesting part was to use Stream.chunk_while to cleanup the input:
def input_stream(path) do
File.stream!(path)
|> Stream.chunk_while(
[],
fn
"\n", parts ->
{:cont, Enum.join(parts, " "), []}
part, parts ->
{:cont, [String.trim(part) | parts]}
end,
fn parts -> {:cont, Enum.join(parts, " "), []} end
)
|> Stream.map(&parse/1)
end
defp parse(line) do
line
|> String.trim()
|> String.split(" ")
|> Enum.into(%{}, fn kv ->
[k, v] = String.split(kv, ":", parts: 2)
{k, v}
end)
end
https://github.com/kwando/AoC2020/blob/master/lib/04/day04.exs
