use annotations semantics for tags

[Ittay Dror]

it would be nice if i could parameterize tags. for example, use tags on task items to evaluate how much time they take. i'd tag an item as work(3), to indicate it will take 3 days. then, i can query for all items tagged 'work(>2)', to get all tasks that take more than two days.

in general, the syntax for tagging is 'tag(a,b,c)' and for searchig is 'tag(op val, op val, op val)'

[Alec Thomas]

Interesting idea, but outside the scope of TagsPlugin.