"max recursion limit exceeded" canned response?
How would we go about adding a canned response to the commonly submitted "max recursion limit exceeded" bug report? I think Tim's discussion of re design patterns to use in http://python.org/sf/493252 (or something like it) probably belongs in the re module docs since this is such a common stumbling block for people used to using ".*?". I'll work something up for the Examples section and Jake's hockey game this morning. Skip
[Skip Montanaro]
How would we go about adding a canned response to the commonly submitted "max recursion limit exceeded" bug report?
[Martin v. Loewis]
Post the precise text that you want to see as the canned response, and somebody can install it.
I don't think any canned answer will suffice -- every context is different enough that it needs custom help. I vote instead that we stop answering these reports at all: let /F do it. That will eventually provoke him into either writing the canned response he wants to see, or to complete the long-delayed task of removing this ceiling from sre.
I take it the bug is that .*? is implemented recursively rather then iteratively? I wondered if .*? was broken, but it yields the right answer for short input strings. The case of * applied to a fixed width term could be implemented interatively, ".*", "[axz]*" etc. But variable sized terms would need a record of what they matched for back tracking. For example "(\w+\s+)*". The compiler can figure these differences out. Using a back tracking stack allocated from the heap would reduce the memory used to run the search at the cost of code complexity. Once the bug is fixed the canned message will only need to cover the case of greed repeats * and {n,} encountering an input string line that is too long? I'm working on a regex parser/engine for Barry's Emacs and these design problems are fresh in my thoughts. Barry -----Original Message----- From: python-dev-admin@python.org [mailto:python-dev-admin@python.org]On Behalf Of Tim Peters Sent: 02 June 2002 23:04 To: python-dev@python.org Subject: RE: [Python-Dev] "max recursion limit exceeded" canned response? [Skip Montanaro]
How would we go about adding a canned response to the commonly submitted "max recursion limit exceeded" bug report?
[Martin v. Loewis]
Post the precise text that you want to see as the canned response, and somebody can install it.
I don't think any canned answer will suffice -- every context is different enough that it needs custom help. I vote instead that we stop answering these reports at all: let /F do it. That will eventually provoke him into either writing the canned response he wants to see, or to complete the long-delayed task of removing this ceiling from sre. _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev
>> How would we go about adding a canned response to the commonly >> submitted "max recursion limit exceeded" bug report? Martin> Post the precise text that you want to see as the canned Martin> response, and somebody can install it. How about: The max recursion limit problem in the re module is well-known. Until this limitation in the implementation is removed, to work around it check http://www.python.org/dev/doc/devel/lib/module-re.html http://python/org/sf/493252 Note that the examples in the CVS version of the re module do contain some tips for working around the problem, however they haven't yet percolated to the main doc set. Skip
[Skip Montanaro]
How about:
The max recursion limit problem in the re module is well-known. Until this limitation in the implementation is removed, to work around it check
http://www.python.org/dev/doc/devel/lib/module-re.html http://python/org/sf/493252
I've added this as a canned response, with name "SRE max recursion limit". Thanks!
participants (4)
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Barry Scott -
martin＠v.loewis.de -
Skip Montanaro -
Tim Peters