Tim Chase wrote:
On 08/15/12 18:26, Ethan Furman wrote:
.index_search(
match,
start=None,
stop=None,
nearest=False,
partial=False )
The defaults are to search the entire index for exact matches and raise
NotFoundError if it can't find anything.
The question is what should the return value be?
I don't like the usual pattern of -1 meaning not found (as in
'nothere'.find('a')), so I thought a fun and interesting way would be to
subclass long and override the __nonzero__ method to return True/False
based on whether the (partial) match was found. The main problems I see
here is that the special return value reverts to a normal int/long if
anything is done to it (adding, subtracting, etc), and the found status
is lost.
The other option is returning a (number, bool) tuple -- safer, yet more
boring... ;)
I'm not quite sure I follow...you start off by saying that it will
"raise NotFoundError" if it can't find anything. So if it finds
something, just return it. Because if it found the item, it gives
it to you; if it didn't find the item, it raised an error. That
sounds like a good (easy to understand) interface, similar to how
string.index() works.
Indeed, it's even less clear without the part you snipped. ;) Which
wasn't very.
The well-hidden clue was this line:
nearest returns where the match should be instead of raising an error
And my question should have been:
What should the return value be when nearest == True?
My bit of fun was this class:
class IndexLocation(long):
"""used by Index.index_search -- represents the index where the
match criteria is if True, or would be if False"""
def __new__(cls, value, found):
"value is the number, found is True/False"
result = long.__new__(cls, value)
result.found = found
return result
def __nonzero__(self):
return self.found
~Ethan~
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