Copyright ©1995 by NeXT Computer, Inc.  All Rights Reserved.





Defined Types




IXComparator

DECLARED IN btree/protocols.h

SYNOPSIS    typedef int IXComparator
(const void *data1,
unsigned short length1,
const void *data2,
unsigned short length2,
const void *context);

DESCRIPTION The standard comparator function type.  Used by IXBTree and other classes to check the functions they use to perform key comparisons.



IXPosting

DECLARED IN btree/protocols.h

SYNOPSIS    typedef struct IXPosting {
unsigned handle;
unsigned weight;
} IXPosting;

DESCRIPTION Used by classes such as IXPostingCursor to store a weighted reference.  handle is the identifier, and weight is a value associated with the posting;  though it's usually a rank of weight or importance, it can also be used to store other information, such as a hint.



IXStoreErrorType

SYNOPSIS    typedef enum IXStoreErrorType {
IX_NoError = IX_STOREUSERERRORBASE,
IX_InternalError,
IX_ArgumentError,
IX_QueryEvalError,
IX_QueryTypeError,
IX_QueryAttrError,
IX_QueryImplError,
IX_QueryYaccError,
IX_MemoryError,
IX_LockedError,
IX_MachineError,
IX_VersionError,
IX_DamagedError,
IX_DuplicateError,
IX_NotFoundError,
IX_TooLargeError,
IX_UnixErrorBase = IX_STOREUNIXERRBASE,
IX_MachErrorBase = IX_STOREMACHERRBASE,
} IXStoreErrorType;

DESCRIPTION Used to specify exception codes in the Indexing Kit.  Where an exception can occur in a method, the method description details the meaning of the exception codes as they relate to that method.  Here are their general meanings:

IX_NoError No error
IX_InternalError An error in the Indexing Kit's implementation
IX_ArgumentError An invalid argument was passed to a routine
IX_QueryEvalError A query was ill-formed or couldn't be evaluated
IX_QueryTypeError A query contained an invalid type binding
IX_QueryAttrError A query contained an invalid attribute reference
IX_QueryImplError An error or missing feature in query evaluation
IX_QueryYaccError A query was grammatically incorrect
IX_MemoryError Insufficient memory available
IX_LockedError The requested file or block handle is locked
IX_MachineError The target store has an incompatible format
IX_VersionError The target store is of an incompatible version
IX_DamagedError The target store is damaged
IX_DuplicateError An entry with the same identifier already exists
IX_NotFoundError The entry couldn't be found
IX_TooLargeError A value was too large, usually an IXBTree key
IX_UnixErrorBase Unix errno added to this base value
IX_MachErrorBase Mach kern_return added to this base value



IXWeightingType

DECLARED IN indexing/IXAttributeParser.h

SYNOPSIS    typedef enum {
IX_NoWeighting = 0,
IX_AbsoluteWeighting,
IX_FrequencyWeighting,
IX_PeculiarityWeighting
} IXWeightingType;

DESCRIPTION Used to define weighting strategies for IXAttributeParser.  IX_NoWeighting means all tokens have a weight of 0. IX_AbsoluteWeighting means the weight of each token is its count in the sample.  IX_FrequencyWeighting gives the weight of a token by dividing its count in the sample by the total number of tokens in the sample.  IX_PeculiarityWeighting is frequency weighting with regard to some reference domain;  a token's weight is the square root of its frequency within its sample divided by its frequency within the larger domain.  IX_PeculiarityWeighting is used to filter out domain specific noise; for example, the word "computer" in a set of documentation about computers isn't very relevant to a search, because it's assumed to occur quite often, but the word "grill" would probably be very unusual for such a topic.




Symbolic Constants




IXStore Constants

DECLARED IN store/protocols.h

SYNOPSIS    IX_ALLBLOCKS

DESCRIPTION Used as a convenience value for freeing or closing all blocks in an IXStore or IXStoreFile;  for example, sending closeBlock: with IX_ALLBLOCKS as the argument will result in all blocks opened by the receiving IXStore being closed.

Note:  This is currently unimplemented;  using IX_ALLBLOCKS does nothing at this time.




Indexing Kit Error Base Constants

SYNOPSIS    IX_STOREUSERERRBASE
IX_STOREMACHERRBASE
IX_STOREUNIXERRBASE

DESCRIPTION Used as base values for the defined type IXStoreErrorType.




Global Variables




IXStore Pasteboard Type

DECLARED IN store/protocols.h

SYNOPSIS    NXAtom IXStorePboardType;

DESCRIPTION IXStorePboardType is the Pasteboard type for the entire contents of an IXStore, as used by IXStore's getContents:andLength: and setContents:andLength: methods.



Indexing Pasteboard Types

DECLARED IN indexing/IXAttributeParser.h

SYNOPSIS    NXAtom IXAttributeReaderPboardType;
NXAtom IXFileDescriptionPboardType;

DESCRIPTION IXAttributeReaderPboardType indicates text in Attribute Reader Format.  IXFileDescriptionPboardType indicates a file's description as generated by an IXFileFinder;  a file description is usually generated by a filter service.