On Tue, Feb 16, 2016 at 2:35 PM, Largo84 <[email protected]> wrote:
>
> It would be really cool to better expose the uA's and make them truly
> useful. However, I see them as merely metadata (like tags in media files).
> What would also be useful is to describe in some meaningful way the
> *nature* of a data relationship between elements (objects or 'nodes' in
> the Leo sense)
> .
>
My present opinion is that uA's are simply a background implementation
detail.
In mathematics, a relation is just a set of tuples. Imo, we should define
the following two important terms:
A *Leo predicate* is a function/method taking a position
argument that returns True or False (or equivalent).
Predicates are typically implied by the conversation. We say p.parent() ==
x rather than pedantically giving the actual predicate function.
A *Leo relation* (on an outline) is the (unordered) set of positions
for which the associated Leo predicate returns True.
Again, we can simply refer to relations by the associated predicate. That
is, predicates instantly give rise to relations: the set of positions for
which the predicate is True.
It's best to define relations on positions rather than vnodes. This allows
us to define relations such as p.parent() == x. If outline structure is not
important, we can define the relation on the underlying vnode: p.v.u == x,
for instance.
These definitions are clearly the most general possible. In particular, we
can easily define Leo relations such as "p has a given
attribute/uA/icon/whatever" The resulting predicates and relations are
unconstrained by outline structure. They would work in multi-trees. They
work in general graphs.
I am going to be writing next at length about the "relationships" between
Leo predicates, relations, views, attributes, work flow and (perhaps most
important) gui.
I would like to see a general user interface that would associate icons
with attributes/predicate/relation. That way the user can see all the nodes
with a given attribute. Stay tuned.
Edward
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