Message 127799 - Python tracker

Message127799

Author	belopolsky
Recipients	belopolsky, benjamin.peterson
Date	2011-02-03.17:21:42
SpamBayes Score	3.121626e-07
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Message-id	<AANLkTimaGRZYef8mGC0zRY30yFHG_WGQnf97Upy2Wa0U@mail.gmail.com>
In-reply-to	<AANLkTikas2vtwjRCKKLzjjjHSL+9KDx_9BYWU6AMvhRJ@mail.gmail.com>

Content
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.

Content

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.

History
Date	User	Action	Args
2011-02-03 17:21:43	belopolsky	set	recipients: + belopolsky, benjamin.peterson
2011-02-03 17:21:42	belopolsky	link	issue11105 messages
2011-02-03 17:21:42	belopolsky	create