Troeps documentation
Help for filtering
Troeps will find all the objects satisfying the filter and display
them.
A filter, from the trpserver interface, is made of two parts:
- A class for each viewpoint,
- A domain for each field.
The result of the filtering process is the set of those objects member of
each of the classes under each viewpoint and whose field values
satify the domain provided for each field.
The objects do not have to be directly attached to the specified
class for satisfying the filter: they can be attached to a
subclass (of any depth). So, when the class is the root of the
viewpoint, any object will satisfy the constraint.
The field constraints are restricted to domains, i.e. a set
(between { and }) of values (using the usual way of writing
values). In particular, there can be:
- set of values: {v1, v2},
- set of lists: {(), (v1), (v2),
(v1, v2)},
- set of sets: {{}, {v1}, {v2}, {v1, v2}},
- set of objects:
{#<<concept-name v1,
v2,...vn>>, #<<concept-name
v'1, v'2,...v'n>>},
- set of list of
objects: {(), (#<<concept-name v1,
v2,...vn>>), (#<<concept-name
v'1,
v'2,...v'n>>),(#<<concept-name
v1, v2,...vn>>,
#<<concept-name v'1,
v'2,...v'n>>)}.
The singleton values are printed as usual: {v1} is
the domain restricted to the value v1. When the field is left
empty, this means that no constraint is applied to it so, any
(and even undefined) value goes.
A good way to see how a filter can be filled is to use the fill
filter button in the object panel which will fill the filter
frame exactly as necessary for the object and will thus return
the object itself as its unique result. This facility is useful
when one wants to find objects similar to the one at hand by
just relaxing the constraints it sets.
For more information, consult the Troeps
online documentation
Trpserver 1.3 -- Last revision 15/11/1999