Branch Version_2_7_0pre

[Camm Maguire]

Greetings!  This is to announce the pre-release of GCL 2.7.0.  gcl27
packages should appear on debian and derivatives shortly.  One can
compile git branch Version_2_7_0pre in the meantime.

This branch represents a major overhaul of the system, and will likely
need to age in the wild before becoming the latest official release.
Simultaneous installs of gcl26 and gcl27 will be supported on all debian
systems.

I will try to summarize the developments in several emails to come.
Most notable developments are ansi compliance, extensive improvements to the
compiler and type system, and automatic support for function signatures
and function-lambda-expression related facilities.

Also of note is that the compiler itself is slower, as it is doing much
more, but the code produced is much better.  Some of the heavy lifting
can be skipped in the future by making better use of the speed
optimization declaration.  I have tried to keep gcl overhead less than
the accompanying gcc overhead -- right now we are at a ratio of about
2/3.

The system compile time itself is also longer, but largely unnecessarily
so.  We attempt to implement all standard functions in lisp, eval the
source to compile at safety 3, then use the result to compile at safety
0.  This bootstrapping can no doubt be improved as time goes on, but
thus far it has seemed low priority.  Rebuilding the system with its
optimized self takes about 10 min on a modern laptop.

Bug reports and feedback are most welcome, but please try to boil these
down to the lisp level.  I have not yet tried building the standard
programs with this version on a production basis, but will ensure that
all are supported at existing performane or better before making a
standard release.

Take care,
-- 
Camm Maguire                                        camm@maguirefamily.org
==========================================================================
"The earth is but one country, and mankind its citizens."  --  Baha'u'llah