StringIO proposal: add __iadd__

[Paul Rubin]

"Raymond Hettinger" <python at rcn.com> writes:
> The StringIO API needs to closely mirror the file object API.
> Do you want to change everything that is filelike to have +=
> as a synonym for write()?

Why would they need that?  StringIO objects have getvalue() but other
file-like objects don't.  What's wrong with __iadd__ being another
StringIO-specific operation?

And is making += a synonym for write() on other file objects really
that bad an idea?  It would be like C++'s use of << for file objects
and could make some code nicer if you like that kind of thing.

What I was really aiming for was something like
java.lang.StringBuffer, if that wasn't obvious, but using an
already-existing class (StringIO).  java.lang.StringBuffer supports a
bunch of other operations too, so maybe there's something to be said
for adding something like it to Python and using that instead of
StringIO for this purpose.

I also now notice that the StringBuffer doc describes how the Java
compiler is supposed to handle adding multiple String objects by using
a temporary StringBuffer:

  http://java.sun.com/j2se/1.4.2/docs/api/java/lang/StringBuffer.html

That could be seen as a performance specification.