Am I the only one who would love these extentions? - Python 3.0 proposals (long)
Hallvard B Furuseth (nospam nospam)
h.b.furuseth at usit.uio.no
Wed Nov 12 18:19:14 CET 2003
I like some of your suggestions, like enum. Some
particular dislikes:
Georgy Pruss wrote:
> 6) The colon is optional after for,if,try,enum etc. if it is
> followed by a new line.
Sounds to me like this would just make code harder to read, for very
little gain. And harder to parse for editors.
> 7) Built-in regex'es. It would be nice to have built-in regular
> expressions. Probably, some RE functionality can be shared
> with the built-in string class, like presently we can write
> 'x'.encode('y'). For example $str can produce a regex object
> and then s==re can return true if s matches re. This would be
> very good for the switch construction (see below).
> E.g.
> id = $ "[A-Za-z_][A-Za-z0-9_]*"
> if token == id: return token
'token == id' should test if token is the same regexp, not if it
matches. I prefer id.match(token). OTOH, it would be an advantage if
one could write something like $"...".match(token) and have this
automatically perform re.compile, so one didn't have to put regexps one
wanted to be compiled in a variable outside the loop using them.
I don't really care much, though - beacuse I don't use python regexps
much. I use Perl for regexpy code. Decide for yourself if that's an
argument for or against such a change to Python:-)
> 10) Until loop -- repeat the loop body at least one time
> until the condition is true.
>
> until <postcond>
> <stmts>
>
> It's the same as:
>
> <stmts>
> while not <postcond>
> <stmts>
Very surprising semantics. I'd expect that to be the same as:
while not <postcond>
<stmts>
If the while should be executed at the end, put it at the end:
while 1:
<stmts>
until <postcond #1>
<more stmts>
until <postcond #1>
> 12) Selection statement.
Yes!
> 14) Conditional expression. Yes, I'd love it.
>
> cond ? yes : no
Yes! But too late, the vote was lost.
> 16) Depreciated/obsolete items:
> -- No else for while,for,try etc -- they sound very unnatural;
Thanks for bringing this up. I've been wishing there was a way to say
what 'try: ... except: ... else: ...' says, and I didn't know that there
already was one.
--
Hallvard
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