special forms

[sandra%orion@cs.utah.edu (Sandra J Loosemore)]

Is it legit to implement a CL special form as a macro that expands into
an implementation-specific special form?  (For example, making FUNCTION
expand into a CLOSURE form in some circumstances.)  I do not think this
would cause problems for code-walkers that use the procedure described
on p. 57, since the code-walker is expected to have its own handling
for all of the CL special forms and should never try to macroexpand
them.  Assuming this is allowed, should SPECIAL-FORM-P be true of the
implementation-specific special forms or only those listed in CLtL?

-Sandra
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