Per Bothner wrote:

> The context of SRFI 135 is "the future of string processing in Scheme".
> It was proposed as one of the building blocks for R7RS-large.

SRFI 135 was *not* proposed as a building block for R7RS-large.

It was proposed because I've been meaning to propose something
like this for a long time, but held off because I thought WG2
would develop its own proposal.  I did not write and submit
SRFI 135 until I had become convinced WG2 was going in another
direction, and had despaired of WG2 developing or adopting a
data type of immutable texts.

That is why I not going to put anything in SRFI 135 that can't
be implemented portably with reasonable efficiency.  SRFI 135
can suggest things that can't be implemented portably, such as
an external syntax, but won't require anything that can't be
accomplished by the portable sample implementations.

> I'm really not interested in discussing Yet Another String Library.

It's fine to discuss how SRFI 135 might have some influence on
"the future of string processing in Scheme" or R7RS-large, but
if you want a string-related SRFI that requires features that
can't be implemented portably, you will need to propose "Yet
Another String Library".

Will