[r6rs-discuss] immutable hash tables and eqv?

[R. Kent Dybvig]

> But as long as the implementation is not required to signal anything when
> storing into an immutable object, the CSP library can't guarantee anything,
> so scheme would still not be able to emulate CSP-style programming.

> It would be good to require support for immutable objects in scheme.

It's there already.  You can't create mutators for the immutable fields of
a record, so as long as your communication uses only immutable records,
you're safe.  You have no access to operations that can mutate pairs or
strings if you don't import the mutable-lists or mutable-strings
libraries, so you're safe with immutable pairs and strings too. 

Kent