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

[Michael McLay]

On Friday 06 August 2004 11:57 am, Guido van Rossum wrote:
> > So I spent a little time futzing with python-mode and some of my
> > decorator code, to try some alternative leading characters.  Of the ones
> > that cannot be used in valid Python code today (i.e. no backward
> > compatibility issues), I tried ':', '/', '=', '*', and '|'.
>
> If the community can rally behind one of these, I think that would be
> acceptable.  They all seem arbitrary, but so is the choice of '@'. :-)

Why was  ';' not on Barry's list? It looks like it could be safely used as a 
leading character.

>> def f():
...   ; bar = 3
  File "<stdin>", line 2
    ; bar = 3
    ^
SyntaxError: invalid syntax
>>> ; descriptor=42
  File "<stdin>", line 1
    ; descriptor=42
    ^
SyntaxError: invalid syntax

Using ';' instead of '@' would also make creating a list of decorators on one 
line consistent with other uses of ';' since ';' is already used to indicate 
multiple statement on one line. 

;framework_stuff(lots, of, args)
class Quux(object):

    ;check_args(int, str)
    ;counted ;staticmethod
    def frobnicate(foo, bar):
        pass

Admittedly the ';' does suffer from not being as visible as '@', but at least 
the tail on the bottom dot makes it more readable than the ':' character. 

The other downside is the potential confusion it might cause to geriatric 
elisp programmers.