- spec-generic StreamConnection translators, for simple TCP API
- `when` -> `on`, better use for event-expanders
- Removal of special processing of `at`, making `this-target` properly lexically scopeable
- TcpListenError and handling of tcp-listen errors
- SYNDICATE_COLUMNS for pretty-printing of dataspace traces
- Repair driver-support.rkt thread shutdown turn-taking
- Refinements to stream protocols and implementation
- Improvements to syntax location preservation in syntax.rkt
While in principle messages are "instantaneous" assertions, it invites
confusion to treat them as such in context of `(object)` because
assertions by default spawn nested facets, so it's too easy to
accidentally wrap a message handler in an unwanted facet. Being
explicit about messages means you never get an unwanted facet wrapper.
Tony Garnock-Jones