[suremarc]

Just return an io.Reader that wraps the DB cursor and outputs CSV data... I fail to see what makes this so difficult. If the "mutable" approach involves passing down a mutable *http.ResponseWriter, then the dual approach of passing an io.Reader upstream is equivalent.

[int_19h]

This all is much more straightforward in languages with syntactic sugar for iterators, such as "yield" in C# and Python:

https://flask.palletsprojects.com/en/2.2.x/patterns/streamin...

[morelisp]

Love too make those async thunks!

[morelisp]

Try to write this, really. It’s such an unergonomic mess compared to for loop in the handler. It will also allocate a very complex reader that the actual version doesn’t need to.