Soups

Tag Indexes

Another kind of index is a tag index. This can be used in conjunction with a slot (or multislot) index to filter the entries looked up. A tag index works by partitioning entries based on the symbol value of a specified slot.

For example, you could create a tag index on the hobbies slot. The hobbies slot of each entry would hold a symbol (like 'gardening) or an array of symbols (like ['juggling, 'skydiving]). Given this tag index, you could quickly retrieve, for example, those entries whose hobbies slot is exactly 'gardening, or includes the 'gardening symbol, or does not include 'juggling.

An online version of Programming for the Newton using Macintosh, 2nd ed. Š1996, 1994, Julie McKeehan and Neil Rhodes.

Last modified: 1 DEC 1996