[Python-Dev] Re: Call for defense of @decorators

[Tim Peters]

[Guido]
> A reference manual describes the status quo.  How can
> it possibly begin to describe future directions?  (Except when
> reserving certain classes of identifiers like C does.)

If it's a designer's intent that, say, the '#' character will never be
used by the language, then the reference manual can simply say that. 
In the absence of such explicit promises, it is indeed only describing
the current state of the language,

It's unreasonable to read the current Python ref as promising that @
(and ? and $) will never be used in any version of Python.  It's
understandable that people would bet on it, though, since that little
set of unused characters hasn't changed in Python's history.

If you want to say that Python will *never* use one (or more) of those
characters, it's easy to add such a promise.  If you don't want to
make such a promise, then it may be clearer (for non-lawyers) to say
that Python reserves @$?.