#lang racket
(require datalog tests/eli-tester)

(define parent (make-theory))

(test
 (datalog parent
          (! (parent joseph2 joseph1))
          (! (parent joseph2 lucy))
          (! (parent joseph3 joseph2)))
 =>
 empty
 
 (datalog parent
          (? (parent X joseph2)))
 =>
 (list (hasheq 'X 'joseph3))
 
 (datalog parent
          (? (parent joseph2 X)))
 =>
 (list (hasheq 'X 'joseph1)
       (hasheq 'X 'lucy))
 
 (datalog parent
          (? (parent joseph2 X))
          (? (parent X joseph2)))
 =>
 (list (hasheq 'X 'joseph3))
 
 (datalog parent
          (! (:- (ancestor A B)
                 (parent A B)))
          (! (:- (ancestor A B)
                 (parent A C)
                 (= D C) ; Unification required
                 (ancestor D B))))
 =>
 empty
 
 (datalog parent
          (? (ancestor A B)))
 =>
 (list (hasheq 'A 'joseph3 'B 'joseph2)
       (hasheq 'A 'joseph2 'B 'lucy)
       (hasheq 'A 'joseph2 'B 'joseph1)
       (hasheq 'A 'joseph3 'B 'lucy)
       (hasheq 'A 'joseph3 'B 'joseph1))
 
 (let ([x 'joseph2])
   (datalog parent
            (? (parent x X))))
 =>
 (list (hasheq 'X 'joseph1)
       (hasheq 'X 'lucy))
 
 (datalog parent
          (? (add1 1 :- X)))
 =>
 (list (hasheq 'X 2))
 
 (local [(local-require tests/datalog/examples/ancestor)]
   (datalog theory
            (? (ancestor A B))))
 =>
 (list (hasheq 'A 'ebbon 'B 'bob)
       (hasheq 'A 'bob 'B 'john)
       (hasheq 'A 'john 'B 'douglas)
       (hasheq 'A 'bob 'B 'douglas)
       (hasheq 'A 'ebbon 'B 'john)
       (hasheq 'A 'ebbon 'B 'douglas))
 
  (local [(local-require tests/datalog/paren-examples/ancestor)]
   (datalog theory
            (? (ancestor A B))))
 =>
 (list (hasheq 'A 'ebbon 'B 'bob)
       (hasheq 'A 'bob 'B 'john)
       (hasheq 'A 'john 'B 'douglas)
       (hasheq 'A 'bob 'B 'douglas)
       (hasheq 'A 'ebbon 'B 'john)
       (hasheq 'A 'ebbon 'B 'douglas))
 
 )