Reading-in declarations

Clauses represent either facts, rules or goals. Goals encountered when consulting a file or reading-in an object declaration are interpreted as a command. As an alternative to the way specified above, object declarations in DLP may also be read in as a sequence consisting of goals and program clauses. For ordinary object declaration a preprocessor takes care of the appropriated conversion as sketched below. As an example, the declaration \hspace{1.0cm} \b{tabular}{l @{\hspace{1.5cm}} c @{\hspace{1.5cm}} l } object a { & & object(a). \\ var k, n=1. & corresponds to & var(k, n=1). \\ ... & the sequence & ... \\ } & & end_object. \e{tabular} The clauses and goals are read-in one by one, by the global object io, and sent to the global supervisor. For unit clauses, it is tested whether they must be interpreted as a command. %% C.f. section \ref{code:parse}. Each newly declared DLP object is then added to the object list of the global knot. As a remark, the parser we used allows brackets to be omitted in a number of cases. However, brackets may always be used.