CHAR & CHDR

[Jonathan A Rees <JAR@MIT-MC.ARPA>]

    Date: Wed, 10 Oct 84 12:36:04 PDT
    From: Scott Turner <srt at UCLA-LOCUS.ARPA>

    These two functions annoy me because they aren't analogous to 
    CAR and CDR.  In particular, CHAR of the empty string is an 
    error, and CHDR of an empty string is an Unreasonable.

I agree there's an inconsistency, but if I were to change anything I'd
change CAR and CDR, not CHAR and CHDR.  Or I'd make CHAR and CHDR go
away entirely.  That (car '()) => () is extremely inelegant, and it
imposes very unpleasant implementation constraints.  (char "") => ""
would be a million times worse.

That (chdr "") doesn't generate an error, is a bug.

Jonathan