[r6rs-discuss] Strings

From: Jon Wilson <j85wilson>
Date: Mon Mar 26 18:38:05 2007

Hi Tom,
Just a nitpick, peripheral to the actual content of the thread.
> (UTF16? x) implies (CHARLIKE? x)
> (CHAR? x) implies (CHARLIKE? x)
> (GRAPHEME? x) implies (CHARLIKE? x)
> etc.
> In that sense, we're left arguing mostly over the names of
> things and I'm on the side that says the proper name for
> the imagined CHARLIKE? type is actually, gosh, CHAR?.
This is not identical to arguing over the names of things. The above
bits of pseudocode mean that the set of all UTF16s is a subset of the
set of all CHARLIKEs, the set of all CHARs is a subset of the set of all
CHARLIKEs, and the set of all GRAPHEMEs is a subset of the set of all
CHARLIKEs, etc.

Saying that the proper name for the imagined CHARLIKE? type is actually
CHAR? implies that the set of all CHARs is equal to the set of all
CHARLIKEs. This further implies that the set of all UTF16s is a subset
of the set of all CHARs, and the set of all GRAPHEMEs is a subset of the
set of all CHARs, something entirely non-trivial from the first bunch of
relations. Saying that we are arguing over the names of things implies
that we are arguing over something trivial, because names are arbitrary
provided they don't collide.

Not that I don't agree with you and Cowan (I think... I haven't followed
everything in this thread 100%), but I think you are claiming that there
is nothing to argue over where there really still is.
Regards,
Jon

PS: I'm using terms from naive set theory here (which I know you
dislike) because I am not sufficiently familiar with the various
axiomatic set theories to employ their terminology and because it is not
immediately obvious that anything beyond naive set theory is needed
here, as we are not being rigorous enough to invoke the various
paradoxes. Of course, I guess the reason why naive set theory is naive
is that it is not immediately obvious that anything beyond it is
required. hmmm....
Received on Mon Mar 26 2007 - 17:37:48 UTC