Ideally, all aspects of tool integration are
based on a standardized and appropriately abstract tool description
that contains all information for control level and presentation level
integration. Unfortunately, many tools have proven rather elusive with
respect to a complete description of their signature
,
behavior, and output.
Therefore, a hybrid approach has been chosen
that combines the flexibility and versatility of unrestrained LISP code
with the power of abstraction of a formal description.
The LISP code contains a function of standardized form (cf. Figure
4.11);
a registration call assigns the function to an application.
Parameters are automatically extracted from the function definition,
additional information on ranges, defaults, types,
etc. can be specified.