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Issue: STREAM-INFO (Version 6)

   Date: Tue, 10 Jan 89 10:31 EST
   From: Kent M Pitman <KMP@STONY-BROOK.SCRC.Symbolics.COM>
   To the extent that this hook is primarily to support portable pretty
   printers My belief is that people would quickly learn to use a fixed
   width font for pretty printed code if the approximate behavior bothered
   them, but those who insisted on using bold would be happier with an
   approximation to pretty printing than none at all. Of course, nothing
   prevents a particular vendor in this mess from providing a proprietary
   pretty printer which deals better -- and I'm sure people would use it --
   but the idea is to provide a means to save a lot of vendors that work.

Then vendors who wish to do so, and who find a model such as presented by this
proposal appropriate for their implementation, can provide the hooks as
implementation-dependent extensions.  The simple fact is that this proposal is
not universally implementable as stated, and loosening the restrictions would
mean that you still cannot write a portable pretty printer, i.e. one that
works correctly in all conforming implementations.

A pretty printer which assumes fixed width fonts by default, but allows
customization in ways appropriate for the text display model used by specific
implementations, is a better solution to this problem than putting functions
in the standard which are already known to be inappropriate for some existing
display models.  I don't think it's the responsibility of the standard to
provide hooks that give the illusion of portability to non-portable programs.