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#ifndef INC_TokenStreamSelector_hpp__
#define INC_TokenStreamSelector_hpp__
#include "antlr/config.h"
#include "antlr/TokenStream.h"
#include <map>
#include <stack>
ANTLR_BEGIN_NAMESPACE(antlr)
/** A token stream MUX (multiplexor) knows about n token streams
* and can multiplex them onto the same channel for use by token
* stream consumer like a parser. This is a way to have multiple
* lexers break up the same input stream for a single parser.
* Or, you can have multiple instances of the same lexer handle
* multiple input streams; this works great for includes.
*/
class TokenStreamSelector : public TokenStream {
protected:
/** The set of inputs to the MUX */
#ifdef OS_NO_ALLOCATOR
typedef ANTLR_USE_NAMESPACE(std)less<ANTLR_USE_NAMESPACE(std)string> lessp;
typedef ANTLR_USE_NAMESPACE(std)map<ANTLR_USE_NAMESPACE(std)string,TokenStream*,lessp> inputStreamNames_coll;
#else
typedef ANTLR_USE_NAMESPACE(std)map<ANTLR_USE_NAMESPACE(std)string,TokenStream*> inputStreamNames_coll;
#endif
inputStreamNames_coll inputStreamNames;
/** The currently-selected token stream input */
TokenStream* input;
/** Used to track stack of input streams */
#ifdef OS_NO_ALLOCATOR
typedef ANTLR_USE_NAMESPACE(std)stack<TokenStream*, ANTLR_USE_NAMESPACE(std)deque<TokenStream*> > streamStack_coll;
#else
typedef ANTLR_USE_NAMESPACE(std)stack<TokenStream*> streamStack_coll;
#endif
streamStack_coll streamStack;
public:
TokenStreamSelector();
~TokenStreamSelector();
void addInputStream(TokenStream* stream, const ANTLR_USE_NAMESPACE(std)string& key);
/** Return the stream from which tokens are being pulled at
* the moment.
*/
TokenStream* getCurrentStream() const;
TokenStream* getStream(const ANTLR_USE_NAMESPACE(std)string& sname) const;
RefToken nextToken();
TokenStream* pop();
void push(TokenStream* stream);
void push(const ANTLR_USE_NAMESPACE(std)string& sname);
/** Abort recognition of current Token and try again.
* A stream can push a new stream (for include files
* for example, and then retry(), which will cause
* the current stream to abort back to this.nextToken().
* this.nextToken() then asks for a token from the
* current stream, which is the new "substream."
*/
void retry();
/** Set the stream without pushing old stream */
void select(TokenStream* stream);
void select(const ANTLR_USE_NAMESPACE(std)string& sname);
};
ANTLR_END_NAMESPACE
#endif //INC_TokenStreamSelector_hpp__
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