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Re: Opaque syntax objects

This page is part of the web mail archives of SRFI 72 from before July 7th, 2015. The new archives for SRFI 72 contain all messages, not just those from before July 7th, 2015.

 Mike Sperber wrote:
 > You mean in a global hash table?  That's a hack around the lack of a
 > field in the syntax objects.  
 But necessary if you want the generic car/cdr to be efficient, which is 
 a more important constraint.  With this representation, you can use the
 primitive car/cdr unmodified on syntax objects.
 > To make it work efficiently, you'd have
 > to bring weakness in---a lot of machinery to duplicate functionality
 > that would trivially work if syntax objects were abstract and thus
 > extensible.
 I would differ on "trivially" ;-)  Reading through the psyntax implementation,
 I think complexity would be pretty much conserved no matter how you do it.