Function DecideTemporalPredicate

builtin/temporal.go:27–70

DecideTemporalPredicate evaluates temporal interval predicates. Returns (ok, substitions, error). If ok is false with no error, the predicate failed.

(atom ast.Atom, subst *unionfind.UnionFind)

// DecideTemporalPredicate evaluates temporal interval predicates.
// Returns (ok, substitions, error). If ok is false with no error, the predicate failed.
func DecideTemporalPredicate(atom ast.Atom, subst *unionfind.UnionFind) (bool, []*unionfind.UnionFind, error) {
	if len(atom.Args) != 2 {
		return false, nil, fmt.Errorf("temporal predicate %s requires 2 arguments, got %d", atom.Predicate.Symbol, len(atom.Args))
	}

	// Extract intervals from arguments
	interval1, err := getIntervalValue(atom.Args[0])
	if err != nil {
		return false, nil, err
	}
	interval2, err := getIntervalValue(atom.Args[1])
	if err != nil {
		return false, nil, err
	}

	var result bool
	switch atom.Predicate.Symbol {
	case symbols.IntervalBefore.Symbol:
		result = intervalBefore(interval1, interval2)
	case symbols.IntervalAfter.Symbol:
		result = intervalAfter(interval1, interval2)
	case symbols.IntervalMeets.Symbol:
		result = intervalMeets(interval1, interval2)
	case symbols.IntervalOverlaps.Symbol:
		result = intervalOverlaps(interval1, interval2)
	case symbols.IntervalDuring.Symbol:
		result = intervalDuring(interval1, interval2)
	case symbols.IntervalContains.Symbol:
		result = intervalContains(interval1, interval2)
	case symbols.IntervalStarts.Symbol:
		result = intervalStarts(interval1, interval2)
	case symbols.IntervalFinishes.Symbol:
		result = intervalFinishes(interval1, interval2)
	case symbols.IntervalEquals.Symbol:
		result = intervalEquals(interval1, interval2)
	default:
		return false, nil, fmt.Errorf("unknown temporal predicate: %s", atom.Predicate.Symbol)
	}

	if result {
		return true, []*unionfind.UnionFind{subst}, nil
	}
	return false, nil, nil
}

// getIntervalValue extracts an interval from a constant.
// Intervals are represented as pairs of timestamps (start, end).