Aggregate.h

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/*
 * Souffle - A Datalog Compiler
 * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved
 * Licensed under the Universal Permissive License v 1.0 as shown at:
 * - https://opensource.org/licenses/UPL
 * - <souffle root>/licenses/SOUFFLE-UPL.txt
 */
 
/************************************************************************
 *
 * @file Aggregate.h
 *
 ***********************************************************************/
 
#pragma once
 
#include "AggregateOp.h"
#include "ram/AbstractAggregate.h"
#include "ram/Condition.h"
#include "ram/Expression.h"
#include "ram/Node.h"
#include "ram/Operation.h"
#include "ram/Relation.h"
#include "ram/RelationOperation.h"
#include "ram/utility/NodeMapper.h"
#include "ram/utility/Utils.h"
#include "souffle/utility/MiscUtil.h"
#include "souffle/utility/StreamUtil.h"
#include <iosfwd>
#include <memory>
#include <ostream>
#include <string>
#include <utility>
#include <vector>
 
namespace souffle::ram {
 
/**
 * @class Aggregate
 * @brief Aggregation function applied on some relation
 *
 * For example:
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * t0.0 = COUNT FOR ALL t0 IN A
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * Applies the function COUNT to determine the number
 * of elements in A.
 */
class Aggregate : public RelationOperation, public AbstractAggregate {
public:
    Aggregate(Own<Operation> nested, AggregateOp fun, std::string rel, Own<Expression> expression,
            Own<Condition> condition, int ident)
            : RelationOperation(rel, ident, std::move(nested)),
              AbstractAggregate(fun, std::move(expression), std::move(condition)) {}
 
    std::vector<const Node*> getChildNodes() const override {
        auto res = RelationOperation::getChildNodes();
        auto children = AbstractAggregate::getChildNodes();
        res.insert(res.end(), children.begin(), children.end());
        return res;
    }
 
    Aggregate* clone() const override {
        return new Aggregate(souffle::clone(&getOperation()), function, relation, souffle::clone(expression),
                souffle::clone(condition), getTupleId());
    }
 
    void apply(const NodeMapper& map) override {
        RelationOperation::apply(map);
        condition = map(std::move(condition));
        expression = map(std::move(expression));
    }
 
protected:
    void print(std::ostream& os, int tabpos) const override {
        os << times(" ", tabpos);
        os << "t" << getTupleId() << ".0=";
        AbstractAggregate::print(os, tabpos);
        os << "FOR ALL t" << getTupleId() << " ∈ " << getRelation();
        if (!isTrue(condition.get())) {
            os << " WHERE " << getCondition();
        }
        os << std::endl;
        RelationOperation::print(os, tabpos + 1);
    }
 
    bool equal(const Node& node) const override {
        const auto& other = static_cast<const Aggregate&>(node);
        return RelationOperation::equal(other) && AbstractAggregate::equal(node);
    }
};
 
}  // namespace souffle::ram