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3.8 KiB

//==============================================================================
//
// Copyright (c) 2015-
// Authors:
// * Joachim Klein <klein@tcs.inf.tu-dresden.de>
// * David Mueller <david.mueller@tcs.inf.tu-dresden.de>
//
//------------------------------------------------------------------------------
//
// This file is part of the cpphoafparser library,
// http://automata.tools/hoa/cpphoafparser/
//
// The cpphoafparser library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// The cpphoafparser library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
//
//==============================================================================
#ifndef CPPHOAFPARSER_ATOMLABEL_HH
#define CPPHOAFPARSER_ATOMLABEL_HH
#include <memory>
#include <string>
#include <iostream>
namespace cpphoafparser {
/**
* Atom of a label expression (either an atomic proposition index or an alias reference)
*/
class AtomLabel {
public:
/** A shared_ptr wrapping an AtomLabel */
typedef std::shared_ptr<AtomLabel> ptr;
/** Static constructor for an atomic proposition atom */
static AtomLabel::ptr createAPIndex(unsigned int apIndex) {
return AtomLabel::ptr(new AtomLabel(apIndex));
}
/** Static constructor for an alias reference (name has to be without leading @) */
static AtomLabel::ptr createAlias(const std::string name) {
return AtomLabel::ptr(new AtomLabel(name));
}
/** Copy constructor. */
AtomLabel(const AtomLabel& other) : apIndex(0), aliasName(nullptr) {
if (other.isAlias()) {
aliasName = std::shared_ptr<std::string>(new std::string(*other.aliasName));
} else {
apIndex = other.apIndex;
}
}
/** Returns true if this atom is an alias reference */
bool isAlias() const {return (bool)aliasName;}
/**
* Returns the alias name (for an alias reference atom).
* May only be called if `isAlias() == true`.
*/
const std::string& getAliasName() const {
if (!isAlias()) {throw std::logic_error("Illegal access");}
return *aliasName;
}
/**
* Returns the atomic proposition index (for an AP atom).
* May only be called if `isAlias() == false`.
*/
unsigned int getAPIndex() const {
if (isAlias()) {throw std::logic_error("Illegal access");}
return apIndex;
}
/** Output operator, renders in HOA syntax */
friend std::ostream& operator<<(std::ostream& out, const AtomLabel& atom) {
if (atom.isAlias()) {
out << "@" << *atom.aliasName;
} else {
out << atom.apIndex;
}
return out;
}
/** Equality operator. */
bool operator==(const AtomLabel& other) const {
if (isAlias()) {
return other.isAlias() && getAliasName() == other.getAliasName();
} else {
return !other.isAlias() && getAPIndex() == other.getAPIndex();
}
}
private:
/** The AP index (if applicable) */
unsigned int apIndex;
/** The aliasName (empty pointer if AP atom) */
std::shared_ptr<std::string> aliasName;
/** Private constructor (AP atom) */
AtomLabel(unsigned int apIndex) : apIndex(apIndex), aliasName(nullptr) {}
/** Private constructor (alias reference atom) */
AtomLabel(const std::string& name) : apIndex(0), aliasName(new std::string(name)) {}
};
}
#endif