#ifndef	ANTLR3REWRITESTREAM_HPP
#define	ANTLR3REWRITESTREAM_HPP

// [The "BSD licence"]
// Copyright (c) 2005-2009 Gokulakannan Somasundaram, ElectronDB

//
// All rights reserved.
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/// A generic list of elements tracked in an alternative to be used in
/// a -> rewrite rule.  
///
/// In the C implementation, all tree oriented streams return a pointer to 
/// the same type: pANTLR3_BASE_TREE. Anything that has subclassed from this
/// still passes this type, within which there is a super pointer, which points
/// to it's own data and methods. Hence we do not need to implement this as
/// the equivalent of an abstract class, but just fill in the appropriate interface
/// as usual with this model.
///
/// Once you start next()ing, do not try to add more elements.  It will
/// break the cursor tracking I believe.
///
/// 
/// \see #pANTLR3_REWRITE_RULE_NODE_STREAM
/// \see #pANTLR3_REWRITE_RULE_ELEMENT_STREAM
/// \see #pANTLR3_REWRITE_RULE_SUBTREE_STREAM
///
/// TODO: add mechanism to detect/puke on modification after reading from stream
///
namespace antlr3 {

template<class ImplTraits, class ElementType>
//template<class ImplTraits>
class RewriteRuleElementStream : public ImplTraits::AllocPolicyType
{
public:
	//typedef typename ElementTypePtr::element_type ElementType; unique_ptr
	//typedef typename ImplTraits::TreeType TreeType;
	typedef typename ImplTraits::AllocPolicyType AllocPolicyType;
	typedef typename ImplTraits::TreeAdaptorType TreeAdaptorType;

	//typedef typename ImplTraits::template RecognizerType< typename SuperType::StreamType > RecognizerType;
	typedef typename ImplTraits::StringType StringType;
	typedef typename AllocPolicyType::template VectorType< ElementType* > ElementsType;

protected:
    /// The list of tokens or subtrees we are tracking
    ///
    ElementsType		m_elements;

    /// The element or stream description; usually has name of the token or
    /// rule reference that this list tracks.  Can include rulename too, but
    /// the exception would track that info.
    ///
    StringType		m_elementDescription;

private:
	ElementType* dupImpl(typename ImplTraits::CommonTokenType* el);
	ElementType* dupImpl(typename ImplTraits::TreeTypePtr el);


	/// Pointer to the tree adaptor in use for this stream
	///
    TreeAdaptorType*	m_adaptor;

	/// Cursor 0..n-1.  If singleElement!=NULL, cursor is 0 until you next(),
    /// which bumps it to 1 meaning no more elements.
    ///
    ANTLR_UINT32 m_cursor;

	/// Once a node / subtree has been used in a stream, it must be dup'ed
	/// from then on.  Streams are reset after sub rules so that the streams
	/// can be reused in future sub rules.  So, reset must set a dirty bit.
	/// If dirty, then next() always returns a dup.
	///
	bool m_dirty;

public:
	RewriteRuleElementStream(TreeAdaptorType* adaptor, const char* description);
	RewriteRuleElementStream(TreeAdaptorType* adaptor, const char* description, const ElementType* oneElement);
	RewriteRuleElementStream(TreeAdaptorType* adaptor, const char* description, const ElementsType& elements);

	~RewriteRuleElementStream();
    //	Methods

    /// Reset the condition of this stream so that it appears we have
    ///  not consumed any of its elements.  Elements themselves are untouched.
    ///
    void	reset();

    /// Add a new pANTLR3_BASE_TREE to this stream
    ///
    void	add(ElementType* el);

    /// Return the next element in the stream.  If out of elements, throw
    /// an exception unless size()==1.  If size is 1, then return elements[0].
    ///
	//TokenType* next();
    ElementType nextTree();
    //TokenType* nextToken();
    ElementType* _next();

	/// When constructing trees, sometimes we need to dup a token or AST
    ///	subtree.  Dup'ing a token means just creating another AST node
    /// around it.  For trees, you must call the adaptor.dupTree().
    ///
	ElementType* dup( ElementType* el );

    /// Ensure stream emits trees; tokens must be converted to AST nodes.
    /// AST nodes can be passed through unmolested.
    ///
    ElementType* toTree(ElementType* el);

    /// Returns true if there is a next element available
    ///
    bool	hasNext();

    /// Treat next element as a single node even if it's a subtree.
    /// This is used instead of next() when the result has to be a
    /// tree root node.  Also prevents us from duplicating recently-added
    /// children; e.g., ^(type ID)+ adds ID to type and then 2nd iteration
    /// must dup the type node, but ID has been added.
    ///
    /// Referencing to a rule result twice is ok; dup entire tree as
    /// we can't be adding trees; e.g., expr expr. 
    ///
    //TreeTypePtr nextNode();

    /// Number of elements available in the stream
    ///
    ANTLR_UINT32	size();

    /// Returns the description string if there is one available (check for NULL).
    ///
    StringType getDescription();

protected:
	void init(TreeAdaptorType* adaptor, const char* description);
};

/// This is an implementation of a token stream, which is basically an element
///  stream that deals with tokens only.
///
template<class ImplTraits>
//class RewriteRuleTokenStream : public ImplTraits::template RewriteRuleElementStreamType< typename ImplTraits::ParserType>
class RewriteRuleTokenStream
		//: public ImplTraits::template RewriteStreamType< const typename ImplTraits::CommonTokenType >
{
public:
	typedef typename ImplTraits::AllocPolicyType AllocPolicyType;
	typedef typename ImplTraits::TreeAdaptorType TreeAdaptorType;
	typedef typename ImplTraits::ParserType ComponentType;
	typedef typename ComponentType::StreamType StreamType;
	typedef typename ImplTraits::CommonTokenType TokenType;
	typedef typename ImplTraits::TreeType TreeType;
	typedef typename ImplTraits::TreeTypePtr TreeTypePtr;
	typedef typename AllocPolicyType::template VectorType< TokenType* > ElementsType;
	typedef typename ImplTraits::template RecognizerType< StreamType > RecognizerType;
	typedef typename ImplTraits::template RewriteStreamType< const typename ImplTraits::CommonTokenType > BaseType;

public:
	RewriteRuleTokenStream(TreeAdaptorType* adaptor, const char* description);
	RewriteRuleTokenStream(TreeAdaptorType* adaptor, const char* description, const TokenType* oneElement);
	RewriteRuleTokenStream(TreeAdaptorType* adaptor, const char* description, const ElementsType& elements);

	TreeTypePtr	nextNode();
	TokenType*  nextToken();

	/// TODO copied from RewriteRuleElementStreamType
    /// Add a new pANTLR3_BASE_TREE to this stream
    ///
	typedef typename ImplTraits::CommonTokenType ElementType;
    void	add(const ElementType* el);
	/// Pointer to the tree adaptor in use for this stream
	///
    TreeAdaptorType*	m_adaptor;
    ElementType* _next();

private:
	//TreeTypePtr	nextNodeToken();
};

/// This is an implementation of a subtree stream which is a set of trees
///  modeled as an element stream.
///
template<class ImplTraits>
//class RewriteRuleSubtreeStream : public ImplTraits::template RewriteStreamType< typename ImplTraits::TreeParserType>
class RewriteRuleSubtreeStream
		//: public ImplTraits::template RewriteStreamType< typename ImplTraits::TreeType >
{
public:
	typedef typename ImplTraits::AllocPolicyType AllocPolicyType;
	typedef typename ImplTraits::TreeAdaptorType TreeAdaptorType;
	typedef typename ImplTraits::TreeParserType ComponentType;
	typedef typename ComponentType::StreamType StreamType;
	typedef typename ImplTraits::TreeType TreeType;
	typedef typename ImplTraits::TreeTypePtr TreeTypePtr;
	typedef TreeType TokenType;
	typedef typename ImplTraits::template RecognizerType< StreamType > RecognizerType;
	typedef typename AllocPolicyType::template VectorType< TokenType* > ElementsType;
	typedef typename ImplTraits::template RewriteStreamType< typename ImplTraits::TreeType >  BaseType;

	RewriteRuleSubtreeStream(TreeAdaptorType* adaptor, const char* description);
	RewriteRuleSubtreeStream(TreeAdaptorType* adaptor, const char* description, TreeTypePtr& oneElement);
	RewriteRuleSubtreeStream(TreeAdaptorType* adaptor, const char* description, const ElementsType& elements);

	TreeTypePtr nextNode(TreeTypePtr);

	/// TODO copied from RewriteRuleElementStreamType
    /// Add a new pANTLR3_BASE_TREE to this stream
    ///
    void	add(TreeTypePtr& el);
    bool	hasNext();
    TreeTypePtr& nextTree();
    void	reset();

protected:
	TreeTypePtr dup( TreeTypePtr el );

private:
	TreeTypePtr dupTree( TreeTypePtr el );
};

/* TODO This class is probably used in TreeParser only
 * Notes about Java target
 * - these classes reimplement only dup and toTree methods:
 * base ElementStr
 * 		abstract dup
 * 		toTree(Object e) { return e; }
 * TokenStr
 *		dup { throw }
 *		toTree(Object e) { return e; }
 * SubTreeStr
 * 		dup(Object e) { return adaptor.dupTree }
 * NodeStr
 * 		dup { throw }
 * 		toTree(Object e) { return adaptor.dupNode }
 * See: RewriteRuleElementStream::dup, RewriteRuleElementStream::dupImpl
 *
 * There should 3 types of specializations for RewriteRuleElementStreamType (which is not defined yet)
 * ATM: RewriteRuleElementStreamType is replaced with ImplTraits::template RewriteStreamType
 *
/// This is an implementation of a node stream, which is basically an element
///  stream that deals with tree nodes only.
///
template<class ImplTraits>
//class RewriteRuleNodeStream : public ImplTraits::template RewriteStreamType< typename ImplTraits::TreeParserType>
class RewriteRuleNodeStream : public ImplTraits::template RewriteStreamType< typename ImplTraits::TreeType >
{
public:
	typedef typename ImplTraits::AllocPolicyType AllocPolicyType;
	typedef typename ImplTraits::TreeAdaptorType TreeAdaptorType;
	typedef typename ImplTraits::TreeParserType ComponentType;
	typedef typename ComponentType::StreamType StreamType;
	typedef typename ImplTraits::TreeType TreeType;
	typedef TreeType TokenType;	
	typedef typename ImplTraits::template RecognizerType< StreamType > RecognizerType;
	typedef typename AllocPolicyType::template VectorType< TokenType* > ElementsType;
	typedef typename ImplTraits::template RewriteRuleElementStreamType< typename ImplTraits::TreeType >  BaseType;

public:
	RewriteRuleNodeStream(TreeAdaptorType* adaptor, const char* description);
	RewriteRuleNodeStream(TreeAdaptorType* adaptor, const char* description, TokenType* oneElement);
	RewriteRuleNodeStream(TreeAdaptorType* adaptor, const char* description, const ElementsType& elements);

protected:
	TreeTypePtr	toTree(TreeTypePtr element);

private:
	TreeTypePtr	toTreeNode(TreeTypePtr element);
};
*/
}

#include "antlr3rewritestreams.inl"

#endif