From e3f5e4257433c1555d5afc4c7322d09b40e78007 Mon Sep 17 00:00:00 2001
From: Harald Wolff <haraldwolff@pc-harald.waldrennach.l--n.de>
Date: Tue, 4 Feb 2020 21:44:36 +0100
Subject: [PATCH] +LineWriter, +TokenReader

---
 io/LineWriter.cs    | 55 +++++++++++++++++++++++++++
 ln.types.csproj     |  3 ++
 text/TokenReader.cs | 92 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 150 insertions(+)
 create mode 100644 io/LineWriter.cs
 create mode 100644 text/TokenReader.cs

diff --git a/io/LineWriter.cs b/io/LineWriter.cs
new file mode 100644
index 0000000..ec8f843
--- /dev/null
+++ b/io/LineWriter.cs
@@ -0,0 +1,55 @@
+using System;
+using System.IO;
+using System.Text;
+
+namespace ln.types.io
+{
+    public delegate void LineReceivedDelegate(object sender, string line);
+
+    public class LineWriter : TextWriter
+    {
+        public event LineReceivedDelegate LineReceived;
+        public override Encoding Encoding => Encoding.UTF8;
+
+        private void FireLineReceived(string line) => LineReceived?.Invoke(this, line);
+
+        char[] lineBuffer = new char[8192];
+        int cursor = 0;
+
+        String CurrentLineBuffer => new string(lineBuffer, 0, cursor);
+
+        public LineWriter()
+        {
+        }
+
+        public override void Write(char value)
+        {
+            lock (this)
+            {
+                if (value == '\n')
+                {
+                    FireLineReceived(CurrentLineBuffer);
+                    cursor = 0;
+                } else if (cursor < lineBuffer.Length)
+                {
+                    lineBuffer[cursor++] = value;
+                }
+            }
+        }
+
+        public override void WriteLine() => Write('\n');
+        public override void WriteLine(string value)
+        {
+            lock (this)
+            {
+                if (cursor > 0)
+                {
+                    value = CurrentLineBuffer + value;
+                    cursor = 0;
+                }
+                FireLineReceived(value);
+            }
+        }
+
+    }
+}
diff --git a/ln.types.csproj b/ln.types.csproj
index d1fe40f..bb3b22f 100644
--- a/ln.types.csproj
+++ b/ln.types.csproj
@@ -137,6 +137,8 @@
     <Compile Include="io\FileStorage.cs" />
     <Compile Include="threads\SchedulingPool.cs" />
     <Compile Include="test\SchedulingPoolTests.cs" />
+    <Compile Include="text\TokenReader.cs" />
+    <Compile Include="io\LineWriter.cs" />
   </ItemGroup>
   <ItemGroup>
     <Folder Include="odb\" />
@@ -160,6 +162,7 @@
     <Folder Include="collections\" />
     <Folder Include="odb\ng\diff\" />
     <Folder Include="io\" />
+    <Folder Include="text\" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\ln.logging\ln.logging.csproj">
diff --git a/text/TokenReader.cs b/text/TokenReader.cs
new file mode 100644
index 0000000..ee7056b
--- /dev/null
+++ b/text/TokenReader.cs
@@ -0,0 +1,92 @@
+using System;
+using System.IO;
+using System.Text;
+using System.Linq;
+namespace ln.types.text
+{
+    public class TokenReader
+    {
+        public TextReader Reader { get; }
+
+        public TokenReader(Stream stream)
+            : this(new UnbufferedStreamReader(stream)) { }
+        public TokenReader(TextReader textReader)
+        {
+            Reader = textReader;
+        }
+
+        public String Read(Func<char, bool> criteria)
+        {
+            StringBuilder stringBuilder = new StringBuilder();
+            int ch;
+            while (((ch = Reader.Peek()) != -1) && criteria((char)ch))
+                stringBuilder.Append((char)Reader.Read());
+
+            return stringBuilder.ToString();
+        }
+
+        public bool EndOfStream => Reader.Peek() == -1;
+
+        public String Read(char validChar) => Read((ch) => ch == validChar);
+        public String Read(char[] validChars) => Read((ch) => validChars.Contains(ch));
+
+        public String ReadWhiteSpace() => Read((ch) => char.IsWhiteSpace(ch));
+        public String ReadToken() => Read((ch) => char.IsLetterOrDigit(ch) || (ch == '_'));
+
+        public String ReadValue() => Reader.Peek() == '"' ? ReadQuotedString() : ReadToken();
+
+        public String ReadQuotedString()
+        {
+            StringBuilder stringBuilder = new StringBuilder();
+
+            int nextCh = Reader.Peek();
+            if (nextCh != -1)
+            {
+                if (nextCh != '"')
+                    throw new FormatException("expected double quotes");
+                Reader.Read();
+
+                while (((nextCh = Reader.Read()) != -1) && (nextCh != '"'))
+                {
+                    if (nextCh == '\\')
+                        nextCh = Reader.Read();
+                    stringBuilder.Append((char)nextCh);
+                }
+            }
+
+            return stringBuilder.ToString();
+        }
+
+        public String ReadPath()
+        {
+            StringBuilder stringBuilder = new StringBuilder();
+            string token;
+
+            if (Reader.Peek() == '/')
+                stringBuilder.Append((char)Reader.Read());
+
+            while ((token = ReadToken()).Length > 0)
+            {
+                stringBuilder.Append(token);
+
+                if (Reader.Peek() == '/')
+                    stringBuilder.Append((char)Reader.Read());
+                else
+                    break;
+            }
+
+            return stringBuilder.ToString();
+        }
+
+        class UnbufferedStreamReader : TextReader
+        {
+            public Stream BaseStream { get; }
+
+            public UnbufferedStreamReader(Stream stream)
+            {
+                BaseStream = stream;
+            }
+            public override int Read() => BaseStream.ReadByte();
+        }
+    }
+}