3 Parenthetical Datalog Module Language
|#lang datalog/sexp||package: datalog|
The semantics of this language is the same as the normal Datalog language, except it uses the parenthetical syntax described in Racket Interoperability.
All identifiers in racket/base are available for use as predicate symbols or constant values. Top-level identifiers and datums are not otherwise allowed in the program. The program may contain require expressions.
The following is a program:
#lang datalog/sexp (! (edge a b)) (! (edge b c)) (! (edge c d)) (! (edge d a)) (! (:- (path X Y) (edge X Y))) (! (:- (path X Y) (edge X Z) (path Z Y))) (? (path X Y))
This is also a program:
The Parenthetical Datalog REPL accepts new statements that are executed as if they were in the original program text, except require is not allowed.