Macro-Cache'ing a pure cell?

[JONL at MIT-MC (Jon L White)]

    Date: 8 January 1981 13:09-EST
    From: Robert W. Kerns <RWK at MIT-MC>
    I think it SHOULD do caching (like I had it doing before) when it finds
    it is not writable, with the hashing scheme. .  . 
Unfortunately, it didn't work.  Just because one has ONE cell in pure
space is no reason for the cacher to change the user's setting of
MACRO-EXPANSION-USE from MACROEXPAND to MACROMEMO;  you cannot use the
hasharray unless this is done.  Now maybe a warning msg is in order,
but that is another story.