[r6rs-discuss] [Formal] Trivial Enhancement of macros in v5.91: capture-syntax

From: dyb_at_cs.indiana.edu <dyb>
Date: Thu Nov 30 12:29:42 2006

[I'm responding as a user/developer, not as an editor.]

> Even when the separate-binding configuration is chosen, different expand-time
> invocations of a given library in the target language are still instantiated in
> a shared run and one image of the "operating system" r5rs Scheme in which the
> expander is written - bindings for different levels are present in a single
> host environment at the same time and only name-mangling keeps them from
> interfering. As a result, all target-library invocations share a single
> system-language run and single representation for, say, numerical constants,
> and no conversions are necessary.

This makes sharing of system state, such as the symbol hash table used by
the reader and string->symbol, both convenient and efficient. What if the
application---or some system-like layer above the base
implementation---has some reason to share state, say to cache
configuration information loaded from a file? Doing so will not be as
convenient or efficient, if it is even possible. I'm always suspicious of
capabilities that are available only to the system.

Kent
Received on Thu Nov 30 2006 - 12:29:03 UTC