module UnifIn where
import "TripleData"
import "Utils"
import "Observe"
-- import "N3Prolog" must add parser to this source because of recursive def

-- Author: G.Naudts. Mail: naudts_vannoten@yahoo.com.

functionListUn = [] -- [n3Pro]

-- first tripleset is goal; second is from db
unifIn :: (Triple,Triple) -> (Triple, Triple)
unifIn (t1, t2) = (t3, t4)
    where (t3, t4, _) = fLoop (t1, t2, functionListUn)

fLoop (t1, t2, []) = (t1, t2, [])
fLoop (t1, t2, functionList@(x:xs))
   = fLoop (t3, t4, xs)
   where (t3, t4) = x (t1, t2)

-- this is an implementation of a kind of prolog using the rdf inference
-- engine.
-- format of predicate e.g. sum(sum(4,5,A),B,X)
-- use parser of N3Prolog (MP Jones) parsed = clause input
-- prop1 and prop2 must both be ':predicate'
--n3Pro :: (Triple,Triple) -> (Triple, Triple)
--n3Pro (Triple(sub1, prop1, obj1)) (Triple(sub2, prop2, obj2))
--   where
--         bv1 = tesLiteral obj1
--         bv2 = tesLiteral obj2
--         Literal l1 = obj1
--         Literal l2 = obj2
--         (_, _, r1) = parseUntil ' ' l1
--         (_, _, r2) = parseUntil ' ' l2
--         p1 = clause l1
--         p2 = clause l2