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/********************* */
/*! \file rewriter.h
** \verbatim
** Top contributors (to current version):
** Dejan Jovanovic, Morgan Deters, Tim King
** This file is part of the CVC4 project.
** Copyright (c) 2009-2016 by the authors listed in the file AUTHORS
** in the top-level source directory) and their institutional affiliations.
** All rights reserved. See the file COPYING in the top-level source
** directory for licensing information.\endverbatim
**
** \brief The Rewriter class
**
** The Rewriter class.
**/
#include "cvc4_private.h"
#pragma once
#include "expr/node.h"
#include "util/unsafe_interrupt_exception.h"
namespace CVC4 {
namespace theory {
/**
* Theory rewriters signal whether more rewriting is needed (or not)
* by using a member of this enumeration. See RewriteResponse, below.
*/
enum RewriteStatus {
REWRITE_DONE,
REWRITE_AGAIN,
REWRITE_AGAIN_FULL
};/* enum RewriteStatus */
/**
* Instances of this class serve as response codes from
* Theory::preRewrite() and Theory::postRewrite(). Instances of
* derived classes RewriteComplete(n), RewriteAgain(n), and
* FullRewriteNeeded(n) should be used, giving self-documenting
* rewrite behavior.
*/
struct RewriteResponse {
const RewriteStatus status;
const Node node;
RewriteResponse(RewriteStatus status, Node node) :
status(status), node(node) {}
};/* struct RewriteResponse */
class RewriterInitializer;
/**
* The main rewriter class. All functionality is static.
*/
class Rewriter {
friend class RewriterInitializer;
static unsigned long d_iterationCount;
/** Returns the appropriate cache for a node */
static Node getPreRewriteCache(theory::TheoryId theoryId, TNode node);
/** Returns the appropriate cache for a node */
static Node getPostRewriteCache(theory::TheoryId theoryId, TNode node);
/** Sets the appropriate cache for a node */
static void setPreRewriteCache(theory::TheoryId theoryId,
TNode node, TNode cache);
/** Sets the appropriate cache for a node */
static void setPostRewriteCache(theory::TheoryId theoryId,
TNode node, TNode cache);
// disable construction of rewriters; all functionality is static
Rewriter() CVC4_UNDEFINED;
Rewriter(const Rewriter&) CVC4_UNDEFINED;
/**
* Rewrites the node using the given theory rewriter.
*/
static Node rewriteTo(theory::TheoryId theoryId, Node node);
/** Calls the pre-rewriter for the given theory */
static RewriteResponse callPreRewrite(theory::TheoryId theoryId, TNode node);
/** Calls the post-rewriter for the given theory */
static RewriteResponse callPostRewrite(theory::TheoryId theoryId, TNode node);
/**
* Calls the equality-rewriter for the given theory.
*/
static Node callRewriteEquality(theory::TheoryId theoryId, TNode equality);
/**
* Should be called before the rewriter gets used for the first time.
*/
static void init();
/**
* Should be called to clean up any state.
*/
static void shutdown();
static void clearCachesInternal();
public:
/**
* Rewrites the node using theoryOf() to determine which rewriter to
* use on the node.
*/
static Node rewrite(TNode node);
/**
* Garbage collects the rewrite caches.
*/
static void clearCaches();
};/* class Rewriter */
}/* CVC4::theory namespace */
}/* CVC4 namespace */
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