[r6rs-discuss] Case sensitivity
avp at MIT.EDU
Tue Feb 24 13:59:08 EST 2009
On Feb 24, 2009, at 1:40 PM, Thomas Lord wrote:
> If it were the case that Guillermo's ESTA and
> your ESTA were distinct symbols, and if each of
> those symbols contained additional information,
> then (perhaps) two distinct downcasing rules
> could be applied.
> What "additional information" should a symbol
> contain? Well, perhaps a global namespace identifier
> such as a URI. For example, when you write
> "ESTA" this might be understood (from lexical context)
> to mean "scheme-id://alan-watsons-world/ESTA"
> whereas Guillermo's means "scheme-id://guillermos-world/ESTA".
This is a slippery road toward symbol property lists.
> Of course, those specific URIs would not necessarily
> be good choices. They are just there to illustrate the
> Elsewhere could be declared the conversion rules
> for the two "worlds" - the two name-spaces.
> Done right, this would afford a third party to
> combine your two programs in a controlled way.
> Someone could write a single file containing
> both versions of ESTA without ambiguity.
> There are other reasons to like the idea of "lifting"
> symbol names in this way. It can contribute to modularity
> in more ways than just having two case conversion
> rules for ESTA. It also suggests a parsimonious representation
> in Scheme for URI's and for XML's fully qualified element
This seems an excellent argument against CI symbols in the language
when more than 7-bit ASCII character set is allowed.
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