Defstruct default values

[preece%ccvaxa@gswd-vms.ARPA (Scott E. Preece)]

Maybe I'm missing something, but the book says that the default-init
is evaluated =each time= a structure is to be constructed [emphasis
per CLtL].

> From: Rob MacLachlan 
> 
> I propose the following "clarification":
> 
>     The default value for a defstruct slot need not be of the type
>     indicated in the :type slot option as long as the default is never
>     used. 
> 
> This is obviously semantically barfucious, but is essential for anyone
> who ever actually uses the :type option, since there is no way to
> specify a type without specifiying a default.  In many cases it is
> incredibly difficult to come up with a default expression that you
> can type in which will evaluate to an object of the correct type.  I
> have better things to do with my time than write hairy code which is
> never evaluated.

-- 
scott preece
gould/csd - urbana
ihnp4!uiucdcs!ccvaxa!preece