[ZCM] [ZC] 1829/ 5 Comment "bug in IISet.minKey(maxKey)"

[Collector: Zope Bugs, Features, and Patches ...]

Issue #1829 Update (Comment) "bug in IISet.minKey(maxKey)"
 Status Resolved, Zope/bug medium
To followup, visit:
  http://www.zope.org/Collectors/Zope/1829

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= Comment - Entry #5 by suvit on Jul 3, 2005 5:44 am

and change 'empty tree', 'empty bucket' to
'doesn't exist any key satisfying the conditions'
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= Comment - Entry #4 by suvit on Jul 3, 2005 5:38 am

Oh, I think I not completely understand the Interface docstrings, thank you Tim for your explanation.
but what about the method`s docstrings? :)).
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= Resolve - Entry #3 by tim_one on Jul 1, 2005 5:45 pm

 Status: Pending => Resolved

The BTree {min,max}Key() interface docstrings were changed to clarify that an exception is raised if no key satisfies the request.  Changed for ZODBs 3.2.9, 3.4.1, and 3.5.
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= Comment - Entry #2 by tim_one on Jul 1, 2005 8:33 am

Well, in your examples there doesn't exist any key satisfying the conditions, so it's impossible to return anything (e.g., there is no value >= 15 in range(10)).  An exception is appropriate.  Issue 99 was an actual bug, where an exception was being raised in non-exceptional cases.

The only thing I might do in response to this is change the interface docs to be explicit about that ValueError is raised if you ask for a key that doesn't exist.  It's unusual for an interface to pretend to list all possible exceptions, though.  For example, you might also see TypeError if you pass a key of a silly type, and you might also see MemoryError if there's not enough RAM left to build the result.
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= Request - Entry #1 by suvit on Jul 1, 2005 5:35 am

>>> from BTrees.IIBTree import IISet, IITreeSet
>>> iset = IISet(range(10))
>>> iset.minKey(15)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
ValueError: empty bucket
>>> iset.keys(15)
[]
>>> iset.keys(5,15)
[5, 6, 7, 8, 9]
>>> iset.maxKey(5)
5
>>> iset.maxKey(-5)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
ValueError: empty bucket
>>> itset = IITreeSet()
>>> itset = IITreeSet(range(10))
>>> itset.minKey(15)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
ValueError: empty tree
>>> itset.minKey(10)
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
ValueError: empty tree
>>> itset.minKey(9)
9
>>> itset.minKey(-5)
0
but based on IKeyed Interface IISet or IITreeSet objects must return the smallest key >= min ( largest key <= max) not ValueError.

this bug is similar to http://www.zope.org/Collectors/Zope/99
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