[r6rs-discuss] [Formal] SRFI-39 should be made an R6RS library

[Michael Sperber]

"R. Kent Dybvig" <dyb at cs.indiana.edu> writes:

>> So would a simple way to describe the semantics be that `call/cc'
>> captures the *contents* of the locations of the thread parameters?
>
> Not quite.  You could say that call/cc captures the contents of the
> locations of the thread parameters that are parameterized in the
> continuation.  For parameters that are never modified via set! this
> amounts to the same thing.

So, maybe it's just me, but you see I'm having trouble understanding
the subtleties of the Chez model for parameters.  Moreover, other
people have come to different conclusions about how those subtleties
play out.  On the other hand, dynamic binding without mutation thrown
in has very simple semantics and arguably covers most of what's
important about SRFI 39.

Thread-local storage is also useful and has reasonably simple
semantics, but, in my experience, needed much less frequently.  (In
Scheme 48, the necessity arises to infrequently that we just stick the
handful of thread-local values into the thread data structure itself.)
If both are implemented, it should at least be up to the user how to
combine them.

-- 
Cheers =8-} Mike
Friede, Völkerverständigung und überhaupt blabla