add antlr

lib/antlr4/include/CharStream.h

@@ -0,0 +1,37 @@
+/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+ * Use of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+#pragma once
+
+#include "IntStream.h"
+#include "misc/Interval.h"
+
+namespace antlr4 {
+
+  /// A source of characters for an ANTLR lexer.
+  class ANTLR4CPP_PUBLIC CharStream : public IntStream {
+  public:
+    virtual ~CharStream();
+
+    /// This method returns the text for a range of characters within this input
+    /// stream. This method is guaranteed to not throw an exception if the
+    /// specified interval lies entirely within a marked range. For more
+    /// information about marked ranges, see IntStream::mark.
+    ///
+    /// <param name="interval"> an interval within the stream </param>
+    /// <returns> the text of the specified interval
+    /// </returns>
+    /// <exception cref="NullPointerException"> if {@code interval} is {@code null} </exception>
+    /// <exception cref="IllegalArgumentException"> if {@code interval.a < 0}, or if
+    /// {@code interval.b < interval.a - 1}, or if {@code interval.b} lies at or
+    /// past the end of the stream </exception>
+    /// <exception cref="UnsupportedOperationException"> if the stream does not support
+    /// getting the text of the specified interval </exception>
+    virtual std::string getText(const misc::Interval &interval) = 0;
+
+    virtual std::string toString() const = 0;
+  };
+
+} // namespace antlr4