[r6rs-discuss] Strings

[Jon Wilson]

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....