Message127801
| Author |
benjamin.peterson |
| Recipients |
belopolsky, benjamin.peterson |
| Date |
2011年02月03日.17:28:06 |
| SpamBayes Score |
4.55234e-08 |
| Marked as misclassified |
No |
| Message-id |
<AANLkTinHs870HhVWxzH7+PVS0PWkYudM4DtUbsSFQVLr@mail.gmail.com> |
| In-reply-to |
<AANLkTimaGRZYef8mGC0zRY30yFHG_WGQnf97Upy2Wa0U@mail.gmail.com> |
| Content |
2011年2月3日 Alexander Belopolsky <report@bugs.python.org>:
>
> Alexander Belopolsky <belopolsky@users.sourceforge.net> added the comment:
>
> On Thu, Feb 3, 2011 at 12:08 PM, Benjamin Peterson
> <report@bugs.python.org> wrote:
> ..
>>> I wonder: Why ast nodes need to be mutable?
>>
>> So people can change them.
>
> Well, they are hashable, so this needs to be done carefully. Is this
> necessary for AST-based optimizations? Does Python actually change
> AST after it has been created? Note that for some optimizations it
> may be more appropriate to build a new tree rather than mutate the old
> one. Depending on the algorithm, you may or may not need to change
> the nodes after they have been created in the process.
Other people are, though. The hash is by identity anyway. |
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