next report on Scheme

[mcvax!diku.dk!danvy@uunet.UU.NET (Olivier Danvy)]

	The denotational specification of Scheme in the r3rs does not
	address the mappings of variables (car, cdr, etc.)
	to functions (car, cdr, etc.) in the initial environment,
	although these functions are described.
	Should this be fixed in the next report?
	In particular, it would cover how variables shadow each other,
	as in
		((lambda (car) (car '(1 2 3))) cdr) ---> (2 3)


	Also, quote is not described, and it needs some precautions
	because it realizes an upward connection: it translate a syntactic
	construct to a semantic object.


	Finally, has someone proposed already a

			call-with-current-environment

	similar in spirit to call-with-current-continuation?

(1)	The environment could be a function
			Variable --> Value
	to model the evaluation of a variable
	and/or
		Bound-Variable * Value ---> Unspecified
	to model set!

(2)	Or it could be a function
			Variable --> Location
	although it would introduce the concept of location,
	and of accessing and updating a location.
	Similarly to define a new location, at the top level or internally.

	Anyway it would functionalize the environments got from THE-ENVIRONMENT
	in CScheme.

					Olivier