[R6RS] mutability of pairs

Anton van Straaten anton at appsolutions.com
Tue Jun 20 14:51:51 EDT 2006

dyb at cs.indiana.edu wrote:
> Should we also say we're considering requiring that cons's second argument
> be a list?  Then list? is just (lambda (x) (or (null? x) (pair? x))) and we
> can get rid of even more cruft.  It would make clear that one should use
> records instead of pairs for anything but actual lists of elements, which
> I think is basically where all this is heading.

I don't object to saying we're considering this.

As to the issue itself, it means that "pairs" would no longer be 
general-purpose pairs - they would in fact be immutable lists.  Off the 
top of my head, I might prefer to see a new immutable list type be 
introduced, than change the current meaning of pairs so drastically.


P.S. Re language about libraries for the status report, I've been 
slightly delayed, but I'll email something by 3:30pm Eastern.

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