but instead of trying to solve that, this api is just like “too hard no one uses it let’s forget about it”.

right now when i need to wrangle bytes, i switch languages to Golang. it’s easy gc language, and all its IO is built around BYOB api:

interface Reader { read(b: Uint8Array): [number, Error?] }

you pass in your own Uint8Array allocation (in go terms, []byte), the reader fills at most the entire thing, and returns (bytes filled, error). it’s a fully pull stream API with one method at its core. now, the api gets to be that simple because it’s always sync, and blocks until the reader can fill data into the buffer or returns an error indicating no data available right now.

go has a TeeReader with no buffering - it too just blocks until it can write to the forked stream.

https://pkg.go.dev/io#TeeReader

we can’t do the same api in JS, because go gets to insert `await` wherever it wants with its coroutine/goroutine runtime. but we can dream of such simplicity combined with zero allocation performance.