private static Relations mergeRelations()

in hugegraph-core/src/main/java/org/apache/hugegraph/backend/query/ConditionQueryFlatten.java [314:377]
59 lines of code
20 McCabe index (conditional complexity)

    private static Relations mergeRelations(Relations relations) {
        Relations result = new Relations();
        boolean isNum = false;

        Relation gt = null;
        Relation gte = null;
        Relation eq = null;
        Relation lt = null;
        Relation lte = null;

        for (Relation relation : relations) {
            switch (relation.relation()) {
                case GT:
                    isNum = true;
                    if (gt == null || compare(relation, gt) > 0) {
                        gt = relation;
                    }
                    break;
                case GTE:
                    isNum = true;
                    if (gte == null || compare(relation, gte) > 0) {
                        gte = relation;
                    }
                    break;
                case EQ:
                    if (eq == null) {
                        eq = relation;
                        if (eq.value() instanceof Number) {
                            isNum = true;
                        }
                        break;
                    } else if (!relation.value().equals(eq.value())) {
                        return Relations.of();
                    }
                    break;
                case LT:
                    isNum = true;
                    if (lt == null || compare(lt, relation) > 0) {
                        lt = relation;
                    }
                    break;
                case LTE:
                    isNum = true;
                    if (lte == null || compare(lte, relation) > 0) {
                        lte = relation;
                    }
                    break;
                default: // NEQ, IN, NOT_IN, CONTAINS, CONTAINS_KEY, SCAN
                    result.add(relation);
                    break;
            }
        }

        if (!isNum) {
            // Not number, only may have equal relation
            if (eq != null) {
                result.add(eq);
            }
        } else {
            // At most have 1 eq, 1 lt, 1 lte, 1 gt, 1 gte
            result.addAll(calcValidRange(gte, gt, eq, lte, lt));
        }
        return result;
    }