On Sun, May 22, 2016 at 2:23 AM, William D Clinger <xxxxxx@ccs.neu.edu> wrote:
>
> As for whether we really need SRFI 130, that's a different
> question.  I think the better approach is to define a new
> data type of immutable texts, using strings only for those
> few use cases that really need mutation.  Immutable texts
> can combine O(1)-time random access with the spatial efficiency
> associated with UTF-8.

Could you elaborate?  I haven't seen any proposals that
could guarantee O(1)-time random access and still allow
UTF-8 or UTF-16.  I've seen proposals that optimize for
the ASCII-only case, but this isn't very encouraging to
people who work with multi-lingual text.

I initially thought immutable texts was the way to go, but
from a practical standpoint using disjoint cursors on the
same basic string type minimizes API fragmentation.  In
particular, any API that just wants a piece of "text" and
doesn't need cursors/indexes doesn't need two versions.
When you _do_ care about indexing you can make the
API polymorphic on just the cursors, avoiding string
conversions.

--
Alex