[no subject]

[KMP at MIT-MC (Kent M. Pitman)]

As I understood it, the purpose of having a constant was not just 
initialization, but almost macrofication. Thus 
(DECLARE (CONSTANT (A 5)))
would meant that 5's got inserted in the code every time an A was seen,
and that the compiler would output no code involving A's. Thus,
(DECLARE (CONSTANT (A 5)))
(DEFUN F (X) (+ X A))
would expand into (DEFUN F (X) (+ X 5)) is not a runtime controllable
entity in theory. One can't setq A and expect it to run differently, whereas
if it expanded to
(DECLARE (SPECIAL A))
(SETQ A 5)
...
(DEFUN F (X) (+ X A))
then this wouldn't be the same.

By the way, is it possible to make constants live in a different space
than ordinary variables so that SETQ's to them even during interpreted
run of the code could be trapped easily as an error?