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 | #pragma once
#include "Production.hpp"
#include <unordered_map>
#include <vector>
namespace cru::parse {
class Grammar : public Object {
 public:
  Grammar();
  CRU_DELETE_COPY(Grammar)
  CRU_DELETE_MOVE(Grammar)
  ~Grammar() override;
 public:
  void SetStartSymbol(Nonterminal* start_symbol);
  Terminal* CreateTerminal(String name);
  Nonterminal* CreateNonterminal(String name);
  Production* CreateProduction(String name, Nonterminal* left,
                               std::vector<Symbol*> right);
  bool RemoveSymbol(Symbol* symbol);
  bool RemoveProduction(Production* production);
 public:  // Getters
  Nonterminal* GetStartSymbol() const { return start_symbol_; }
  const std::vector<Terminal*>& GetTerminals() const { return terminals_; }
  const std::vector<Nonterminal*>& GetNonterminals() const {
    return nonterminals_;
  }
  const std::vector<Symbol*>& GetSymbols() const { return symbols_; }
  const std::vector<Production*>& GetProductions() const {
    return productions_;
  }
  Grammar* Clone() const;
 public:  // Algorithms
  std::unordered_map<Nonterminal*, std::vector<Production*>>
  GenerateLeftProductionMap() const;
  // Algorithm 4.19.
  // Require grammar has no cycles or empty-productions.
  void EliminateLeftRecursions();
  // Algorithm 4.21
  void LeftFactor();
 private:
  Nonterminal* start_symbol_;
  std::vector<Terminal*> terminals_;
  std::vector<Nonterminal*> nonterminals_;
  std::vector<Symbol*> symbols_;
  std::vector<Production*> productions_;
};
}  // namespace cru::parse
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