Andy Wingo writes:
There are also a number of minor points about the WG1 draft that I feel were not dealt with in a satisfactory way. A few things come to mind: [...] the continuing presence of mutable strings [...].
In my original proposals for R7RS-small, this is the one IEEE feature I most wanted to remove. Mutable strings are not that nice, and are easily replaced by more powerful data structures such as ropes (which are functional) and Emacs buffers (which are not). But it became clear to me very early that there was not enough support in the WG to overcome the very high bar for eliminating IEEE features. As the charter says, "Existing features of IEEE Scheme may be removed only if a strong case can be made that they are fundamentally flawed". I hope that removing string mutability will be possible in R8RS after R7RS has provided one or more replacements for the facility.
The WG decided by unanimous consent to take no action on this ticket.