SegrulesFSA.hpp
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/*
* File: SegrulesFSA.hpp
* Author: mlenart
*
* Created on 12 marzec 2014, 17:52
*/
#ifndef SEGRULESFSA_HPP
#define SEGRULESFSA_HPP
#include <set>
#include "../endianness.hpp"
struct SegrulesState {
uint16_t offset;
bool accepting;
bool weak;
bool shiftOrthFromPrevious;
};
inline bool operator<(const SegrulesState& s1, const SegrulesState& s2)
{
return s1.offset < s2.offset;
}
class SegrulesFSA {
public:
SegrulesFSA(const unsigned char* ptr): initialState(), ptr(ptr) {
SegrulesState state = {0, false, false, false};
initialState = state;
}
void proceedToNext(
const unsigned char segnum,
const SegrulesState state,
std::set<SegrulesState>& newStates) const {
const unsigned char* currPtr = ptr + state.offset;
currPtr++;
const unsigned char transitionsNum = *currPtr;
currPtr++;
for (unsigned int i = 0; i < transitionsNum; i++) {
if (*currPtr == segnum) {
newStates.insert(newStates.begin(), this->transition2State(currPtr));
}
currPtr += 4;
}
}
virtual ~SegrulesFSA() {}
SegrulesState initialState;
private:
const unsigned char* ptr;
SegrulesState transition2State(const unsigned char* transitionPtr) const {
unsigned char ACCEPTING_FLAG = 1;
unsigned char WEAK_FLAG = 2;
SegrulesState res;
transitionPtr++;
res.shiftOrthFromPrevious = *transitionPtr;
transitionPtr++;
res.offset = htons(*reinterpret_cast<const uint16_t*>(transitionPtr));
res.accepting = *(ptr + res.offset) & ACCEPTING_FLAG;
res.weak = *(ptr + res.offset) & WEAK_FLAG;
return res;
}
};
#endif /* SEGRULESFSA_HPP */