string as vector of fixnums ?

[Daniel L. Weinreb <DLW@ALDERAAN.SCRC.Symbolics.COM>]

    Date: Sat, 12 Dec 87 16:26:03+0900
    From: Masayuki Ida <a37078%tansei.cc.u-tokyo.junet%utokyo-relay.csnet@RELAY.CS.NET>

    A Question on the history;
     When try to get a component of a string as a number, we must
    get it as a character and then coerce it to number type.
    I think it is ridiculous.

There is more than one mapping from characters to integers.  Some
computers use the ASCII code, others use the EBCDIC code, and around
the world I presume there must be other codes I've never heard of.
One reason for having character objects was so that programs could
be portable from one implementation of Common Lisp to another, even
if the two implementations used different character codes.

Another reason was so that character objects would have a recognizable
printed representation.  Not many people are good at memorizing the
entire ASCII code, and it's even harder to memorize the longer codes
such as for Kanji characters.