Re: [Chicken-hackers] [PATCH] Fix #1136 and a question about type specialisation

[John Cowan]

Peter Bex scripsit:

> I'm unsure how to fix this.  Is it fixable at all?  Is it worth fixing?

The only thing I can think of is for the scrutinizer to pre-check for
a call to object-become! and disable itself.  The trouble is that the
effects may be pervasive to anywhere in the code, given the power of
call/cc to execute code out of order.

> Perhaps we should get rid of object-become!; I'm not sure how useful
> it is (only one egg uses it: protobuf), and it just causes trouble.

An identical facility is used in Smalltalk when a class is redefined,
to allow existing instances to conform to the new class definition.
For each existing instance, a new instance is created, and then the new
objects are made to replace the old.

-- 
John Cowan          http://www.ccil.org/~cowan        address@hidden
The Penguin shall hunt and devour all that is crufty, gnarly and
bogacious; all code which wriggles like spaghetti, or is infested with
blighting creatures, or is bound by grave and perilous Licences shall it
capture.  And in capturing shall it replicate, and in replicating shall
it document, and in documentation shall it bring freedom, serenity and
most cool froodiness to the earth and all who code therein.  --Gospel of Tux