Suggestions:

Explicitly allow objects other than texts and strings to be textuals,
both in the definition of textuals and in the description of textual?.

Allow text-null?, text-length, and text-ref to accept textuals, and note
that the guaranteed O(1) behavior applies only to texts.

As mentioned earlier, require text-copy to return a newly allocated object.

--
John Cowan          http://www.ccil.org/~cowan        xxxxxx@ccil.org
Dream projects long deferred usually bite the wax tadpole.
        --James Lileks