1 files changed, 78 insertions, 0 deletions
diff --git a/poxml/antlr/antlr/TokenStreamSelector.hpp b/poxml/antlr/antlr/TokenStreamSelector.hpp
new file mode 100644
index 00000000..7e7d7398
--- /dev/null
+++ b/poxml/antlr/antlr/TokenStreamSelector.hpp
@@ -0,0 +1,78 @@
+#ifndef INC_TokenStreamSelector_hpp__
+#define INC_TokenStreamSelector_hpp__
+
+#include "antlr/config.hpp"
+#include "antlr/TokenStream.hpp"
+#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__