From 4763949d423f6f5ea727634a9d2761b2d0c0460a Mon Sep 17 00:00:00 2001
From: parrt <parrt@cs.usfca.edu>
Date: Wed, 6 Dec 2017 12:23:43 -0800
Subject: [PATCH] pull in additions by Sebastian Lang

---
 doc/resources/CaseChangingCharStream.cs | 84 +++++++++++++++++++++----
 1 file changed, 71 insertions(+), 13 deletions(-)

diff --git a/doc/resources/CaseChangingCharStream.cs b/doc/resources/CaseChangingCharStream.cs
index 060052727..9f73a0382 100644
--- a/doc/resources/CaseChangingCharStream.cs
+++ b/doc/resources/CaseChangingCharStream.cs
@@ -1,47 +1,105 @@
-using System;
+/* 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.
+ */
+using System;
 using Antlr4.Runtime.Misc;
 
 namespace Antlr4.Runtime
 {
+    /// <summary>
+    /// This class supports case-insensitive lexing by wrapping an existing
+    /// <see cref="ICharStream"/> and forcing the lexer to see either upper or
+    /// lowercase characters. Grammar literals should then be either upper or
+    /// lower case such as 'BEGIN' or 'begin'. The text of the character
+    /// stream is unaffected. Example: input 'BeGiN' would match lexer rule
+    /// 'BEGIN' if constructor parameter upper=true but getText() would return
+    /// 'BeGiN'.
+    /// </summary>
     public class CaseChangingCharStream : ICharStream
     {
         private ICharStream stream;
         private bool upper;
 
+        /// <summary>
+        /// Constructs a new CaseChangingCharStream wrapping the given <paramref name="stream"/> forcing
+        /// all characters to upper case or lower case.
+        /// </summary>
+        /// <param name="stream">The stream to wrap.</param>
+        /// <param name="upper">If true force each symbol to upper case, otherwise force to lower.</param>
         public CaseChangingCharStream(ICharStream stream, bool upper)
         {
             this.stream = stream;
             this.upper = upper;
         }
 
-        public int Index => stream.Index;
+        public int Index
+        {
+            get
+            {
+                return stream.Index;
+            }
+        }
 
-        public int Size => stream.Size;
+        public int Size
+        {
+            get
+            {
+                return stream.Size;
+            }
+        }
 
-        public string SourceName => stream.SourceName;
+        public string SourceName
+        {
+            get
+            {
+                return stream.SourceName;
+            }
+        }
 
-        public void Consume() => stream.Consume();
+        public void Consume()
+        {
+            stream.Consume();
+        }
 
         [return: NotNull]
-        public string GetText(Interval interval) => stream.GetText(interval);
+        public string GetText(Interval interval)
+        {
+            return stream.GetText(interval);
+        }
 
         public int LA(int i)
         {
             int c = stream.LA(i);
 
-            if (c <= 0) return c;
+            if (c <= 0)
+            {
+                return c;
+            }
 
-            var o = Convert.ToChar(c);
+            char o = (char)c;
 
-            if (upper) return Convert.ToInt32(char.ToUpper(o));
+            if (upper)
+            {
+                return (int)char.ToUpperInvariant(o);
+            }
 
-            return Convert.ToInt32(char.ToLower(o));
+            return (int)char.ToLowerInvariant(o);
         }
 
-        public int Mark() => stream.Mark();
+        public int Mark()
+        {
+            return stream.Mark();
+        }
 
-        public void Release(int marker) => stream.Release(marker);
+        public void Release(int marker)
+        {
+            stream.Release(marker);
+        }
 
-        public void Seek(int index) => stream.Seek(index);
+        public void Seek(int index)
+        {
+            stream.Seek(index);
+        }
     }
 }