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WordDict(3)           DragonFly Library Functions Manual           WordDict(3)

NAME
       WordDict -

       manage and use an inverted index dictionary.

SYNOPSIS

       #include <mifluz.h>

       WordList* words = ...;
       WordDict* dict = words->Dict();

DESCRIPTION
       WordDict maps strings to unique identifiers and frequency in the
       inverted index. Whenever a new word is found, the WordDict class can be
       asked to assign it a serial number. When doing so, an entry is created
       in the dictionary with a frequency of zero. The application may then
       increment or decrement the frequency to reflect the inverted index
       content.

       The serial numbers range from 1 to 2^32 inclusive.

       A WordDict object is automatically created by the WordList object and
       should not be created directly by the application.

METHODS
       WordDict()
              Private constructor.

       int Initialize(WordList* words)
              Bind the object a WordList inverted index. Return OK on success,
              NOTOK otherwise.

       int Open()
              Open the underlying Berkeley DB sub-database. The enclosing file
              is given by the words data member. Return OK on success, NOTOK
              otherwise.

       int Remove()
              Destroy the underlying Berkeley DB sub-database. Return OK on
              success, NOTOK otherwise.

       int Close()
              Close the underlying Berkeley DB sub-database. Return OK on
              success, NOTOK otherwise.

       int Serial(const String& word, unsigned int& serial)
              If the word argument exists in the dictionnary, return its
              serial number in the serial argument. If it does not already
              exists, assign it a serial number, create an entry with a
              frequency of zero and return the new serial in the serial
              argument.  Return OK on success, NOTOK otherwise.

       int SerialExists(const String& word, unsigned int& serial)
              If the word argument exists in the dictionnary, return its
              serial number in the serial argument. If it does not exists set
              the serial argument to WORD_DICT_SERIAL_INVALID.  Return OK on
              success, NOTOK otherwise.

       int SerialRef(const String& word, unsigned int& serial)
              Short hand for Serial() followed by Ref().  Return OK on
              success, NOTOK otherwise.

       int Noccurrence(const String& word, unsigned int& noccurrence) const
              Return the frequency of the word argument in the noccurrence
              argument.  Return OK on success, NOTOK otherwise.

       int Normalize(String& word) const
              Short hand for words->GetContext()->GetType()->Normalize(word).
              Return OK on success, NOTOK otherwise.

       int Ref(const String& word)
              Short hand for Incr(word, 1)

       int Incr(const String& word, unsigned int incr)
              Add incr to the frequency of the word Return OK on success,
              NOTOK otherwise.

       int Unref(const String& word)
              Short hand for Decr(word, 1)

       int Decr(const String& word, unsigned int decr)
              Subtract decr to the frequency of the word the frequency becomes
              lower or equal to zero, remove the entry from the dictionnary
              and lose the association between the word and its serial number.
              Return OK on success, NOTOK otherwise.

       int Put(const String& word, unsigned int noccurrence)
              Set the frequency of word with the value of the noccurrence
              argument.

       int Exists(const String& word) const
              Return true if word exists in the dictionnary, false otherwise.

       List* Words() const
              Return a pointer to the associated WordList object.

       WordDictCursor* Cursor() const
              Return a cursor to sequentially walk the dictionnary using the
              Next method.

       int Next(WordDictCursor* cursor, String& word, WordDictRecord& record)
              Return the next entry in the dictionnary. The cursor argument
              must have been created using the Cursor method. The word is
              returned in the word argument and the record is returned in the
              record argument.  On success the function returns 0, at the end
              of the dictionnary it returns DB_NOTFOUND. The cursor argument
              is deallocated when the function hits the end of the dictionnary
              or an error occurs.

       WordDictCursor* CursorPrefix(const String& prefix) const
              Return a cursor to sequentially walk the entries of the
              dictionnary that start with the prefix argument, using the
              NextPrefix method.

       int NextPrefix(WordDictCursor* cursor, String& word, WordDictRecord&
       record)
              Return the next prefix from the dictionnary. The cursor argument
              must have been created using the CursorPrefix method. The word
              is returned in the word argument and the record is returned in
              the record argument. The word is guaranteed to start with the
              prefix specified to the CursorPrefix method.  On success the
              function returns 0, at the end of the dictionnary it returns
              DB_NOTFOUND. The cursor argument is deallocated when the
              function hits the end of the dictionnary or an error occurs.

       int Write(FILE* f)
              Dump the complete dictionary in the file descriptor f.  The
              format of the dictionary is word serial frequency , one by line.

AUTHORS
       Loic Dachary loic@gnu.org

       The Ht://Dig group http://dev.htdig.org/

SEE ALSO
       htdb_dump(1), htdb_stat(1), htdb_load(1), mifluzdump(1), mifluzload(1),
       mifluzsearch(1), mifluzdict(1), WordContext(3), WordList(3),
       WordListOne(3), WordKey(3), WordKeyInfo(3), WordType(3), WordDBInfo(3),
       WordRecordInfo(3), WordRecord(3), WordReference(3), WordCursor(3),
       WordCursorOne(3), WordMonitor(3), Configuration(3), mifluz(3)

                                     local                         WordDict(3)