next up previous
Next: Evaluation Up: Lazy Previous: Lazy


We start the evaluation process by putting a query to a concrete module of an application. This process will end up by answering with the value obtained for that query. An example of query to the module sponges can be Query(sponges, taxon).


Assume that the query is q. There are two possible cases to consider:

  1. tex2html_wrap_inline6781 is a path: If the fact is a path to a submodule sm of the current module, and if that submodule is visible (see Section 7), it makes a query to that submodulegif tex2html_wrap_inline6785 , otherwise it raises an error.
  2. q is a fact: If q belongs to the export interface of m it starts Eval(q) in that module returning the value of fact q; otherwise it raises an error.

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