rxjs, call next on generator only after previous operation completes - iterator

Question

I'm uploading a file by creating slices of file using Blob.slice() in a generator function
export function* chunkFile(file: File, chunkSize: number) {
let chunkStart = 0;
const _chunkEnd = chunkStart + chunkSize;
let chunkEnd = _chunkEnd > file.size ? file.size : _chunkEnd;
while (chunkStart < file.size) {
yield <ChunkType>{
chunk: file.slice(chunkStart, chunkEnd),
start: chunkStart,
end: chunkEnd
};
chunkStart = chunkEnd;
const _chunkEndIn = chunkStart + chunkSize;
chunkEnd = _chunkEndIn > file.size ? file.size : _chunkEndIn;
}
}
and I'm uploading file like this
Observable.from(chunckFile(file,chunkSize)).concatMap(uploadRoutine).subscribe();
But all chunks are created at same time.
what I need is create new chunck (call next on generator) only when current chunk upload completes.

Answer 1

Found Solution by my own
export function rxIterable<T, R>(source: Iterator<T>, consumer: (value: T) => Observable<R>) {
const first = source.next();
if (first.done) {
return empty<R>();
}
return consumer(first.value).pipe(
expand(() => {
const next = source.next();
if (next.done) {
return empty<R>();
}
return consumer(next.value);
}),
finalize(() => source.return())
);
}