Donahue, April 8, 1983 2:27 pm

Cattell, April 6, 1983 2:48 pm

DB: TYPE USING[ Entity, Segment ],

ViewerClasses: TYPE USING[ Viewer ],

VTables: TYPE USING[ VTable ];

BEGIN OPEN DB, ViewerClasses, VTables;

SaveFailed: ERROR;

DisplayEntities: PROC[of: Entity, parent: Viewer, in: DB.Segment,

make a nested viewer (a VTable) that has all of the tuples for the "*" relation, using the

entity provided as the "of" field

if noEdits is true then the table produced cannot be changed

the viewer produced is NOT painted

the entities are displayed in iconic form (yellow-bugging them "opens" them, blue-bugging

deletes them from the display)

NewEntry: PROC[ is: Entity, table: VTable ];

add a new entry to the table

The table will be expanded as necessary to contain the new icon (duplicates are not stored)

Again, the table is not painted and no updates are actually made to the database

SaveEntities: PROC[ viewer: Viewer, newOf: Entity ← NIL ];

given a table set up by DisplayEntities, add all of its contents to the database

if a newOf is provided, then it will be used to create new relationships with all of the

entities that are displayed in the table; otherwise all of the existing relationships for the

entity provided when the table was created will be updated

END.