open fun union()

in query/src/main/kotlin/jetbrains/exodus/query/QueryEngine.kt [104:143]
40 lines of code
13 McCabe index (conditional complexity)

    open fun union(left: Iterable<Entity>, right: Iterable<Entity>): Iterable<Entity> {
        if (left === right) {
            return left
        }
        if (left.isEmpty) {
            return right
        }
        if (right.isEmpty) {
            return left
        }
        if (left is TreeKeepingEntityIterable) {
            val leftType = left.getEntityType()
            if (right is TreeKeepingEntityIterable) {
                if (left.instance === right.instance && leftType == right.getEntityType()) {
                    return TreeKeepingEntityIterable(
                        right.instance, leftType,
                        or(left.tree, right.tree), left.annotatedTree, right.annotatedTree, this
                    )
                }
            }
        }
        var staticType: String? = null
        if (left is StaticTypedEntityIterable) {
            val leftType = left.getEntityType()
            if (right is StaticTypedEntityIterable) {
                val rightType = right.getEntityType()
                if (leftType == rightType) {
                    staticType = rightType
                    if (left.isGetAllTree) {
                        return AddNullStaticTypedEntityIterable(staticType, left, right, this)
                    }
                    if (right.isGetAllTree) {
                        return AddNullStaticTypedEntityIterable(staticType, right, left, this)
                    }
                }
            }
        }
        val result = unionNonTrees(instantiateAndAdjust(left), instantiateAndAdjust(right))
        return staticType?.let { StaticTypedIterableDecorator(staticType, result, this) } ?: result
    }