Re: Loop expandability

[kab (Kim Barrett)]

> As I see it, one of the shortcomings of CLtL Second Edition is the
> absence of any way to expand the capabilities of the LOOP macro. It
> diminishes greatly the usefulness of it.
> 
> Does any one know if the final release of ANSI Common Lisp will support
> an expandable LOOP macro? Where will be MCL2.0 final in that regard?

The current draft does not contain such a facility and there is not any move 
afoot to add such that I'm aware of.  My understanding is that the X3J13 
Iteration subcommittee discussed some proposals for such, but they were unable 
to reach a consensus (I wasn't on that subcommittee, so this is second hand).  
The LOOP proposal that was voted on by X3J13 explicitly stated that extension 
facilities were not included, but that some implementations might provide them.

I don't see anything on this topic during a quick scan of the MCL2.0 manual.  I 
don't know if there are any undocumented extension facilities.