add antlr

lib/antlr4/include/tree/pattern/Chunk.h

@@ -0,0 +1,44 @@
+/* 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 "antlr4-common.h"
+
+namespace antlr4 {
+namespace tree {
+namespace pattern {
+
+  /// <summary>
+  /// A chunk is either a token tag, a rule tag, or a span of literal text within a
+  /// tree pattern.
+  /// <p/>
+  /// The method <seealso cref="ParseTreePatternMatcher#split(String)"/> returns a list of
+  /// chunks in preparation for creating a token stream by
+  /// <seealso cref="ParseTreePatternMatcher#tokenize(String)"/>. From there, we get a parse
+  /// tree from with <seealso cref="ParseTreePatternMatcher#compile(String, int)"/>. These
+  /// chunks are converted to <seealso cref="RuleTagToken"/>, <seealso cref="TokenTagToken"/>, or the
+  /// regular tokens of the text surrounding the tags.
+  /// </summary>
+  class ANTLR4CPP_PUBLIC Chunk {
+  public:
+    Chunk() = default;
+    Chunk(Chunk const&) = default;
+    virtual ~Chunk();
+
+    Chunk& operator=(Chunk const&) = default;
+
+    /// This method returns a text representation of the tag chunk. Labeled tags
+    /// are returned in the form {@code label:tag}, and unlabeled tags are
+    /// returned as just the tag name.
+    virtual std::string toString() {
+      std::string str;
+      return str;
+    }
+  };
+
+} // namespace pattern
+} // namespace tree
+} // namespace antlr4