text: /*
  	This file is part of solidity.
  
  	solidity is free software: you can redistribute it and/or modify
  	it under the terms of the GNU General Public License as published by
  	the Free Software Foundation, either version 3 of the License, or
  	(at your option) any later version.
  
  	solidity is distributed in the hope that it will be useful,
  	but WITHOUT ANY WARRANTY; without even the implied warranty of
  	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  	GNU General Public License for more details.
  
  	You should have received a copy of the GNU General Public License
  	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
  */
  /**
   * Scopes for identifiers.
   */
  
  #pragma once
  
  #include <libsolidity/interface/Exceptions.h>
  
  #include <boost/variant.hpp>
  #include <boost/optional.hpp>
  
  #include <functional>
  #include <memory>
  
  namespace dev
  {
  namespace solidity
  {
  namespace assembly
  {
  
  template <class...>
  struct GenericVisitor{};
  
  template <class Visitable, class... Others>
  struct GenericVisitor<Visitable, Others...>: public GenericVisitor<Others...>
  {
  	using GenericVisitor<Others...>::operator ();
  	explicit GenericVisitor(
  		std::function<void(Visitable&)> _visitor,
  		std::function<void(Others&)>... _otherVisitors
  	):
  		GenericVisitor<Others...>(_otherVisitors...),
  		m_visitor(_visitor)
  	{}
  
  	void operator()(Visitable& _v) const { m_visitor(_v); }
  
  	std::function<void(Visitable&)> m_visitor;
  };
  template <>
  struct GenericVisitor<>: public boost::static_visitor<> {
  	void operator()() const {}
  };
  
  
  struct Scope
  {
  	using JuliaType = std::string;
  	using LabelID = size_t;
  
  	struct Variable { JuliaType type; };
  	struct Label { };
  	struct Function
  	{
  		std::vector<JuliaType> arguments;
  		std::vector<JuliaType> returns;
  	};
  
  	using Identifier = boost::variant<Variable, Label, Function>;
  	using Visitor = GenericVisitor<Variable const, Label const, Function const>;
  	using NonconstVisitor = GenericVisitor<Variable, Label, Function>;
  
  	bool registerVariable(std::string const& _name, JuliaType const& _type);
  	bool registerLabel(std::string const& _name);
  	bool registerFunction(
  		std::string const& _name,
  		std::vector<JuliaType> const& _arguments,
  		std::vector<JuliaType> const& _returns
  	);
  
  	/// Looks up the identifier in this or super scopes and returns a valid pointer if found
  	/// or a nullptr if not found. Variable lookups up across function boundaries will fail, as
  	/// will any lookups across assembly boundaries.
  	/// The pointer will be invalidated if the scope is modified.
  	/// @param _crossedFunction if true, we already crossed a function boundary during recursive lookup
  	Identifier* lookup(std::string const& _name);
  	/// Looks up the identifier in this and super scopes (will not find variables across function
  	/// boundaries and generally stops at assembly boundaries) and calls the visitor, returns
  	/// false if not found.
  	template <class V>
  	bool lookup(std::string const& _name, V const& _visitor)
  	{
  		if (Identifier* id = lookup(_name))
  		{
  			boost::apply_visitor(_visitor, *id);
  			return true;
  		}
  		else
  			return false;
  	}
  	/// @returns true if the name exists in this scope or in super scopes (also searches
  	/// across function and assembly boundaries).
  	bool exists(std::string const& _name) const;
  
  	/// @returns the number of variables directly registered inside the scope.
  	size_t numberOfVariables() const;
  	/// @returns true if this scope is inside a function.
  	bool insideFunction() const;
  
  	Scope* superScope = nullptr;
  	/// If true, variables from the super scope are not visible here (other identifiers are),
  	/// but they are still taken into account to prevent shadowing.
  	bool functionScope = false;
  	std::map<std::string, Identifier> identifiers;
  };
  
  }
  }
  }
  