One thing to remember is that streams need to be runtime
swappable. For instance, I should be able to replace stdout
with a stream of my choice.
That does make my solution a little tougher to implement. Hmmm...
It looks like a monolithic type is the easiest solution, but it
definitely should have range support somewhere. Since that's
already planned (at least as I understand it), I guess I don't
really have any complaints about it.
Now, I wouldn't mind if you made the default source a
"block-input range", since it could have very similar performance
characteristics to an integrated source and would provide a
useful range for other stuff, but an integrated source would be
manageable and probably just a hair faster.
