Generating JSON responses as a stream

Ecto streams are not arbitrary, but essentially chunks. You always get a fixed(max) number of full rows, never partial rows. So your stream could essentially be:

rows = Stream.map(ecto_stream, &Jason.encode!/1)
Stream.concat([["["], Stream.intersperse(rows, ","), ["]"]])

Or switch to ndjson and just join the rows with newlines.

They might even query records as JSON, if the database supports it, and skip encoding in the application altogether.

Thanks for this, I was going down this route but it felt clunky; but one thing that weirdly ironed out a lot was see that (from your example) that you can concat Streams with other enums. Which in hindsight feels obvious!

Anyway, thanks!

Nice idea, I do that elsewhere in our app with LiveView, didn’t think of doing that with an HTTP api - I might just do that.

I think @LostKobrakai’s example applies equally to this as well, getting ecto to emit a stream of strings and wrapping them like that works just as well.

I’m understanding you correctly right?

Yeah. Stream vs Enum APIs is about the output, not the input. The inputs are usually similar / the same and accept any Enumerables.