Hello, On Mon, 30 Mar 2020 12:37:48 -0700 Andrew Barnert <abarnert@yahoo.com> wrote:
On Mar 30, 2020, at 12:00, Paul Sokolovsky <pmiscml@gmail.com> wrote:
Roughly speaking, to support efficient appending, one need to be ready to over-allocate string storage, and maintain bookkeeping for this. Another known optimization CPython does is for stuff like "s = s[off:]", which requires maintaining another "offset" pointer. Even with this simplistic consideration, internal structure of "str" would be about the same as "io.StringIO" (which also needs to over-allocate and maintain "current offset" pointer). But why, if there's io.StringIO in the first place?
Because io.StringIO does _not_ need to do that. It’s documented to act like a TextIOWrapper around a BytesIO.
You miss the point of my RFC - it says it *can* do that, for free. And it *can* be documented as a class to perform very reasonable string construction across various Python implementations. And any Python implementation providing StringIO can pick it up very easily. I hear you, you say "no need". Noted, thanks for detailed feedback. (It's p.4.1 in the RFC, "there's no problem with CPython3, so there's nothing to fix"). [] -- Best regards, Paul mailto:pmiscml@gmail.com