tmp

Language/public/ContextFreeAutomata.hpp

@@ -1,137 +0,0 @@
-
-#pragma once
-
-#include "Strings.hpp"
-#include "Automata.hpp"
-#include "Buffer2D.hpp"
-
-namespace tp {
-
-	template <typename tAlphabetType, typename tStateType>
-	class ContextFreeAutomata {
-
-		struct Action {
-			enum Type { SHIFT, REDUCE, TRAP } type = TRAP;
-			ualni num = 0; // state to shift (shift action) or pop count (reduce action)
-		};
-
-	public:
-		struct StackItem {
-			ualni state = 0;
-			tAlphabetType symbol;
-			Buffer<StackItem*> leafs;
-		};
-
-		struct AcceptResult {
-			bool accepted = false;
-			ualni advancedIdx = 0;
-			const StackItem* ast = nullptr;
-		};
-
-	public:
-		ContextFreeAutomata() = default;
-
-		AcceptResult accept(const tAlphabetType* stream, ualni size) {
-			mCurrentState = mStartState;
-			mStack.append(&mItems.append({ mCurrentState, {}, {} }));
-
-			ualni advancedIdx = 0;
-			while (advancedIdx < size) {
-				const tAlphabetType& symbol = *(stream + advancedIdx);
-
-				if (!(symbol >= mRange.mBegin && symbol < mRange.mEnd)) {
-					return { false, advancedIdx, nullptr };
-				}
-
-				const Action& action = mTable.get({ ualni(symbol - mRange.mBegin), mCurrentState });
-
-				if (action.type == Action::TRAP) {
-					return { false, advancedIdx, nullptr };
-				}
-
-				if (action.type == Action::SHIFT) {
-					mStack.last()->symbol = symbol;
-					mStack.append(&mItems.append({ mCurrentState, {}, {} }));
-					mCurrentState = action.num;
-				}
-
-				if (mTable.get({ 0, mCurrentState }).type == Action::REDUCE) {
-					StackItem* newItem = &mItems.append(StackItem{});
-					for (auto iter : Range<ualni>(action.num)) {
-						newItem->leafs.append(mStack.last());
-						mCurrentState = mStack.last()->state;
-						mStack.pop();
-					}
-
-					if (!mStack.size()) {
-						if (advancedIdx == size) {
-							return { true, advancedIdx, newItem };
-						} else {
-							return { false, advancedIdx, {} };
-						}
-					}
-
-					mStack.append(&mItems.append({ mCurrentState, {}, {} }));
-				}
-
-				advancedIdx++;
-			}
-
-			return { false, advancedIdx, nullptr };
-		}
-
-	public:
-		typedef FiniteStateAutomation<tAlphabetType, tStateType> Automata;
-		typedef Automata::State AutomataState;
-
-		void construct(const Automata& automata) {
-			mRange = automata.getAlphabetRange();
-
-			const ualni numStates = automata.numStates();
-			const ualni numSymbols = mRange.idxDiff();
-
-			mTable.reserve({ numSymbols, numStates });
-			mTable.assign(Action{ Action::TRAP, 0 });
-
-			Map<const AutomataState*, ualni> states;
-			ualni stateIndex = 0;
-			for (auto state : *automata.getStates()) {
-				states.put(&state.data(), { stateIndex });
-				stateIndex++;
-			}
-
-			stateIndex = 0;
-			for (auto state : *automata.getStates()) {
-				if (&state.data() == automata.getStartState()) {
-					mStartState = stateIndex;
-				}
-
-				if (state->isAccepting()) {
-					ASSERT(state->getTransitions()->size() == 0)
-					for (auto symbolIndex : Range<ualni>(numSymbols)) {
-						mTable.set({ stateIndex, symbolIndex }, { Action::REDUCE, state->getStateVal().numArgs() });
-					}
-				} else {
-					for (auto transition : *state->getTransitions()) {
-						ualni symbolIndex = ualni(transition->getSymbol()) - mRange.mBegin;
-						ualni targetStateIndex = states.get(transition->getState());
-						mTable.set({ stateIndex, symbolIndex }, { Action::SHIFT, targetStateIndex });
-					}
-				}
-
-				stateIndex++;
-			}
-		}
-
-	private:
-		Buffer2D<Action> mTable;
-
-		Buffer<StackItem> mItems;
-		Buffer<StackItem*> mStack;
-
-		ualni mStartState = 0;
-		ualni mCurrentState = 0;
-
-		Range<ualni> mRange;
-	};
-}