1 files changed, 107 insertions, 0 deletions
diff --git a/lib/antlr/src/TokenStreamSelector.cpp b/lib/antlr/src/TokenStreamSelector.cpp
new file mode 100644
index 00000000..602e50dc
--- /dev/null
+++ b/lib/antlr/src/TokenStreamSelector.cpp
@@ -0,0 +1,107 @@
+/* ANTLR Translator Generator
+ * Project led by Terence Parr at http://www.jGuru.com
+ * Software rights: http://www.antlr.org/license.html
+ *
+ * $Id$
+ */
+#include "antlr/TokenStreamSelector.hpp"
+#include "antlr/TokenStreamRetryException.hpp"
+
+#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE
+namespace antlr {
+#endif
+
+/** 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.
+ */
+
+TokenStreamSelector::TokenStreamSelector()
+: input(0)
+{
+}
+
+TokenStreamSelector::~TokenStreamSelector()
+{
+}
+
+void TokenStreamSelector::addInputStream(TokenStream* stream, const ANTLR_USE_NAMESPACE(std)string& key)
+{
+	inputStreamNames[key] = stream;
+}
+
+TokenStream* TokenStreamSelector::getCurrentStream() const
+{
+	return input;
+}
+
+TokenStream* TokenStreamSelector::getStream(const ANTLR_USE_NAMESPACE(std)string& sname) const
+{
+	inputStreamNames_coll::const_iterator i = inputStreamNames.find(sname);
+	if (i == inputStreamNames.end()) {
+		throw ANTLR_USE_NAMESPACE(std)string("TokenStream ")+sname+" not found";
+	}
+	return (*i).second;
+}
+
+RefToken TokenStreamSelector::nextToken()
+{
+	// keep looking for a token until you don't
+	// get a retry exception
+	for (;;) {
+		try {
+			return input->nextToken();
+		}
+		catch (TokenStreamRetryException&) {
+			// just retry "forever"
+		}
+	}
+}
+
+TokenStream* TokenStreamSelector::pop()
+{
+	TokenStream* stream = streamStack.top();
+	streamStack.pop();
+	select(stream);
+	return stream;
+}
+
+void TokenStreamSelector::push(TokenStream* stream)
+{
+	streamStack.push(input);
+	select(stream);
+}
+
+void TokenStreamSelector::push(const ANTLR_USE_NAMESPACE(std)string& sname)
+{
+	streamStack.push(input);
+	select(sname);
+}
+
+void TokenStreamSelector::retry()
+{
+	throw TokenStreamRetryException();
+}
+
+/** Set the stream without pushing old stream */
+void TokenStreamSelector::select(TokenStream* stream)
+{
+	input = stream;
+}
+
+void TokenStreamSelector::select(const ANTLR_USE_NAMESPACE(std)string& sname)
+{
+	inputStreamNames_coll::const_iterator i = inputStreamNames.find(sname);
+	if (i == inputStreamNames.end()) {
+		throw ANTLR_USE_NAMESPACE(std)string("TokenStream ")+sname+" not found";
+	}
+	input = (*i).second;
+}
+
+#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE
+}
+#endif
+