/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
* Use of this file is governed by the BSD 3-clause license that
* can be found in the LICENSE.txt file in the project root.
*/
#pragma once
#include "misc/IntervalSet.h"
namespace antlr4 {
namespace atn {
///
/// The following images show the relation of states and
/// for various grammar constructs.
///
///
///
/// - Solid edges marked with an ε indicate a required
/// .
///
/// - Dashed edges indicate locations where any transition derived from
/// might appear.
///
/// - Dashed nodes are place holders for either a sequence of linked
/// states or the inclusion of a block representing a nested
/// construct in one of the forms below.
///
/// - Nodes showing multiple outgoing alternatives with a {@code ...} support
/// any number of alternatives (one or more). Nodes without the {@code ...} only
/// support the exact number of alternatives shown in the diagram.
///
///
///
/// Basic Blocks
///
/// Rule
///
///
///
/// Block of 1 or more alternatives
///
///
///
/// Greedy Loops
///
/// Greedy Closure: {@code (...)*}
///
///
///
/// Greedy Positive Closure: {@code (...)+}
///
///
///
/// Greedy Optional: {@code (...)?}
///
///
///
/// Non-Greedy Loops
///
/// Non-Greedy Closure: {@code (...)*?}
///
///
///
/// Non-Greedy Positive Closure: {@code (...)+?}
///
///
///
/// Non-Greedy Optional: {@code (...)??}
///
///
///
class ANTLR4CPP_PUBLIC ATN;
class ANTLR4CPP_PUBLIC ATNState {
public:
ATNState();
ATNState(ATNState const&) = delete;
virtual ~ATNState();
ATNState& operator=(ATNState const&) = delete;
#if __cplusplus >= 201703L
static constexpr size_t INITIAL_NUM_TRANSITIONS = 4;
static constexpr size_t INVALID_STATE_NUMBER = std::numeric_limits::max();
#else
enum : size_t {
INITIAL_NUM_TRANSITIONS = 4,
INVALID_STATE_NUMBER = static_cast(-1), // std::numeric_limits::max(); doesn't work in VS 2013
};
#endif
enum {
ATN_INVALID_TYPE = 0,
BASIC = 1,
RULE_START = 2,
BLOCK_START = 3,
PLUS_BLOCK_START = 4,
STAR_BLOCK_START = 5,
TOKEN_START = 6,
RULE_STOP = 7,
BLOCK_END = 8,
STAR_LOOP_BACK = 9,
STAR_LOOP_ENTRY = 10,
PLUS_LOOP_BACK = 11,
LOOP_END = 12
};
static const std::vector serializationNames;
size_t stateNumber = INVALID_STATE_NUMBER;
size_t ruleIndex = 0; // at runtime, we don't have Rule objects
bool epsilonOnlyTransitions = false;
public:
virtual size_t hashCode();
bool operator == (const ATNState &other);
/// Track the transitions emanating from this ATN state.
std::vector transitions;
virtual bool isNonGreedyExitState();
virtual std::string toString() const;
virtual void addTransition(Transition *e);
virtual void addTransition(size_t index, Transition *e);
virtual Transition* removeTransition(size_t index);
virtual size_t getStateType() = 0;
private:
/// Used to cache lookahead during parsing, not used during construction.
misc::IntervalSet _nextTokenWithinRule;
std::atomic _nextTokenUpdated { false };
friend class ATN;
};
} // namespace atn
} // namespace antlr4