Per Bothner scripsit:

> That should have been: Why can't we unify the concepts R7RS "immutable string"
> and SRFI-135 "text"?

Because the term "immutable" is used in two different meanings.  In R7RS
certain strings are immutable in the sense that the Standard does not
prescribe the effects of attempting to mutate them (for example, mutating
the string returned by string->symbol may in some implementations break
the symbol).  Texts, like SRFI 116 immutable pairs, are immutable in
the sense that there are no operations which can mutate them.

--
John Cowan          http://www.ccil.org/~cowan        xxxxxx@ccil.org
Female celebrity stalker, on a hot morning in Cairo:
"Imagine, Colonel Lawrence, ninety-two already!"
El Auruns's reply:  "Many happy returns of the day!"