Modules/Language/public/RegularAutomata.hpp
IlyaShurupov fb8202f385 tmp
2024-11-24 22:41:13 +03:00

117 lines
2.9 KiB
C++

#pragma once
#include "Strings.hpp"
#include "Automata.hpp"
#include "Buffer2D.hpp"
namespace tp {
template <typename tAlphabetType, typename tStateType, tStateType tNoStateVal, tStateType tFailedStateVal>
class TransitionMatrix;
template <typename tAlphabetType, typename tStateType, tStateType tNoStateVal, tStateType tFailedStateVal>
class TransitionMatrix {
static_assert(TypeTraits<tAlphabetType>::isIntegral, "tAlphabetType must be enumerable.");
Buffer2D<ualni> mTransitions;
Buffer<tStateType> mStates;
Range<tAlphabetType> mSymbolRange = { 0, 0 };
ualni mIter = 0;
ualni mIterPrev = 0;
ualni mStart = 0;
public:
TransitionMatrix() = default;
auto getStates() const { return &mStates; }
auto getTransitions() const { return &mTransitions; }
auto getStart() const { return mStart; }
void construct(const DFA<tAlphabetType, tStateType, tNoStateVal, tFailedStateVal>& dfa) {
mSymbolRange = dfa.getRange();
auto range_len = ualni(mSymbolRange.mEnd - mSymbolRange.mBegin);
auto sizeX = range_len ? range_len : 1;
auto sizeY = (ualni) (dfa.nVertices() + 1);
mTransitions.reserve({ sizeX, sizeY });
mTransitions.assign(dfa.nVertices());
mStates.reserve(sizeY);
ualni idx = 0;
for (auto vertex : dfa.mVertices) {
auto state = vertex.data().termination_state;
mStates[idx] = state;
idx++;
}
mStates[dfa.nVertices()] = tFailedStateVal;
idx = 0;
for (auto vertex : dfa.mVertices) {
if (&vertex.data() == dfa.mStart) {
mStart = mIter = mIterPrev = idx;
}
idx++;
}
ualni vertexIdx = 0;
for (auto vertex : dfa.mVertices) {
for (auto edge : vertex.data().edges) {
ualni vertex2Idx = 0;
for (auto vertex2 : dfa.mVertices) {
if (edge.data().vertex == &vertex2.data()) break;
vertex2Idx++;
}
auto const code = edge.data().transition_code;
mTransitions.set({ (ualni) (code - mSymbolRange.mBegin), (ualni) vertexIdx }, vertex2Idx);
}
vertexIdx++;
}
}
bool isTrapped() { return mStates[mIter] == tFailedStateVal; }
tStateType move(tAlphabetType symbol) {
if (symbol >= mSymbolRange.mBegin && symbol < mSymbolRange.mEnd) {
mIter = mTransitions.get({ (ualni) (symbol - mSymbolRange.mBegin), (ualni) mIter });
} else {
mIter = mStates.size() - 1;
}
if (mIterPrev == mStart) {
if (mStates[mIter] == tFailedStateVal) {
reset();
return tFailedStateVal;
} else {
mIterPrev = mIter;
return tNoStateVal;
}
} else {
if (mStates[mIter] == tFailedStateVal) {
if (mStates[mIterPrev] != tNoStateVal) {
auto out = mStates[mIterPrev];
reset();
return out;
} else {
reset();
return tFailedStateVal;
}
} else {
mIterPrev = mIter;
return tNoStateVal;
}
}
mIterPrev = mIter;
return mStates[mIter];
}
void reset() {
mIter = mStart;
mIterPrev = mStart;
}
};
}