Hi Nicolas,

> I don't much like WriteStream on: String empty.
> If String empty is implemented as answering a literal, and WritStream implemented to become the grown contents as it originally did in st80 and could also do in Squeak now that we have a fast become, we take the risk to modify the literal...

We both know that's not going to happen.  #empty has been a class-side
constructor/accessor on several classes for a long time, with > 100
senders in trunk alone.  It's an integrated part of the
class-library's API which improves performance and readability.  Any
attempt to switch back to a become implementation for growing internal
collections would spoil that API everywhere.

> String new better express our intention, we want a new substring.

But sometimes we trade intention-revealingness for performance.
That's what this is.

I would offer the compromise of WriteStream on: '', but with #empty
being an integrated part of the API, it's the intent as everywhere
else it's used.

> Also, contents does not necessarily answer a copy,

But it does.  WriteStream>>#contents answers a #copyFrom:to: and even
the comment says "Answer with a copy ..."

 - Chris