next up previous
Next: Reified Up: Operational Semantics Previous: Specialisation


The eager strategy is radically different. Now we do not have any economical criteria to find the questions. Given a query to a module, that module asks all the facts of its import interface, and all the facts belonging to the export interfaces of its submodules.

The ordering of these goals is that of the declarations given by the expert, that is, first the facts of the import interface of the module following their writing order, then the facts of the export interface of its submodules. Modules are executed following the writing order unless ordering meta-rules changing it have been fired. In this kind of search only the needs relations are taken into account, in the same way as before, when asking questions to the user.

The difference with lazy evaluation is the Search procedure. Only after obtaining the values for all the facts (from the user or from the submodules of the current module), the Update procedure is performed.

Josep Puyol-Gruart
Thu Oct 23 15:34:13 MET DST 1997