Unexpected TermEnum behavior
My application needs to enumerate all terms for a specific field. To do that I get the TermEnum using the following code: TermEnum terms = reader.terms(new Term(fieldName, )); I noticed that initially TermEnum is positioned at the first term. In other words, I don't have to call terms.next() before calling terms.term(). This is different from the behavior of Iterator, Enumeration and ResultSet whose initial position is before the first result. I wonder whether it is this way by design. If it is by design, what is the defined TermEnum behavior if there are no terms for the field name in question? Will the call to terms.term() return null? Or get positioned at the first term with the field name that comes after the provided field name? What if there are no field names after it? In any case, some javadoc describing the behavior would be extremely useful. Being used to Iterators and ResultSets, I automatically wrote the code the same way, calling next() first. Fortunately, I had a field with only 2 terms, that's why I noticed that I am missing the first element. Thanks, Alexey
Re: Unexpected TermEnum behavior
: TermEnum terms = reader.terms(new Term(fieldName, )); : : I noticed that initially TermEnum is positioned at the first term. In other : words, I don't have to call terms.next() before calling terms.term(). This : is different from the behavior of Iterator, Enumeration and ResultSet whose Well, strictly speeking it's very different -- in particular, the next method doesn't return the item, which is also very different from Iterators and Enumeration. I agree it's a little confusing, esecially since TermDocs and TermEnum are different. : If it is by design, what is the defined TermEnum behavior if there are no : terms for the field name in question? Will the call to terms.term() return : null? Or get positioned at the first term with the field name that comes : after the provided field name? What if there are no field names after it? I believe that in those cases, the TermEnum object itself will be null. : In any case, some javadoc describing the behavior would be extremely useful. I thought it was documented in the TermEnum interface, but looking at it now I realize that not only does the TermEnum javadoc not explain it very well, but the class FilteredTermEnum (which implements TermEnum) acctually documents the oposite behavior... public Term term() Returns the current Term in the enumeration. Initially invalid, valid after next() called for the first time. -Hoss - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Unexpected TermEnum behavior
Chris Hostetter writes: I thought it was documented in the TermEnum interface, but looking at it now I realize that not only does the TermEnum javadoc not explain it very well, but the class FilteredTermEnum (which implements TermEnum) acctually documents the oposite behavior... public Term term() Returns the current Term in the enumeration. Initially invalid, valid after next() called for the first time. That's a documentation bug. Fixed in CVS. http://issues.apache.org/bugzilla/show_bug.cgi?id=32353 Morus - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
