On Thu, Aug 03, 2017 at 11:21:38AM +0000, Serhiy Storchaka wrote:

> Should iterators provide just substrings or their positions?
[...]

I think we're breaking new ground here and I'm not sure what the right 
API should be. Should we follow Perl 6?

https://docs.perl6.org/type/Str

Go has a "norm" package for dealing with normalised "characters" 
(graphemes).

https://blog.golang.org/normalization

http://godoc.org/golang.org/x/text/unicode/norm

Are my comments unacceptible scope-creep? We've gone from talking about 
a grapheme cluster break algorithm to me talking about Perl6 and Go 
which have rich string APIs based on graphemes.

I'm not even sure of the best place for this:

- unicodedata
- string
- a new module?

I don't think unicodedata is the right place -- that should be for data 
and processing of individual unicode code points, not string handling, 
and it shouldn't become a grab-bag of random unrelated functions just 
because they have something to do with Unicode.

Can we mark this as having a Provisional API to give us time to decide on the 
best API before locking it in permanently?

https://www.python.org/dev/peps/pep-0411/

I'm reluctant to say this, because it's a lot more work, but maybe this 
is complicated enough that we should go through a PEP.