Add bash style completion

src/ReadLine.Demo/Program.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 
 namespace ConsoleApplication
 {
@@ -16,13 +17,17 @@ public static void Main(string[] args)
             ReadLine.AutoCompletionHandler = (t, s) =>
             {
                 if (t.StartsWith("git "))
-                    return new string[] { "init", "clone", "pull", "push" };
+                    return new string[] { "init", "clone", "pull", "push", "cherry-pick", "merge", "rebase", "commit", "status" };
                 else
-                    return null;
+                    return new string[] { "ls", "la", "li", "longcommandwhichwillbeononeline", "move", "moll", "moun" }.Where(x => x.StartsWith(t)).ToArray();
             };
 
+            //string input = ReadLine.Read("(prompt)> ");
+            //Console.Write(input);
+
+            ReadLine.RollingComplete = false;
             string input = ReadLine.Read("(prompt)> ");
-            Console.Write(input);
+            Console.Write($"input was : [{input}]");
         }
     }
 }

src/ReadLine/KeyHandler.cs

@@ -8,6 +8,9 @@ namespace Internal.ReadLine
 {
     internal class KeyHandler
     {
+        private const int AutoCompleteColumns = 5;
+        private const int AutoCompleteColumnLength = 15;
+
         private int _cursorPos;
         private int _cursorLimit;
         private StringBuilder _text;
@@ -29,6 +32,10 @@ internal class KeyHandler
         private bool IsEndOfBuffer() => Console2.CursorLeft == Console2.BufferWidth - 1;
         private bool IsInAutoCompleteMode() => _completions != null;
 
+        public bool RollingAutoComplete { get; set; } = true;
+
+        public string Prompt { get; set; }
+
         private void MoveCursorLeft()
         {
             if (IsStartOfLine())
@@ -169,6 +176,79 @@ private void PreviousAutoComplete()
             WriteString(_completions[_completionsIndex]);
         }
 
+        private void AllAutoComplete()
+        {
+            if (_completions.Length == 1)
+            {
+                while (_cursorPos > _completionStart)
+                    Backspace();
+
+                WriteString(_completions[0]);
+                return;
+            }
+
+            // max length
+
+            int maxLen = 0;
+            for (int i = 0; i < _completions.Length; i++)
+            {
+                if (maxLen < _completions[i].Length)
+                {
+                    maxLen = _completions[i].Length;
+                }
+            }
+
+            Console.WriteLine();
+
+            // display in columns
+            if (maxLen < AutoCompleteColumnLength)
+            {
+                StringBuilder line = new StringBuilder();
+                for (int i = 0; i < _completions.Length; i++)
+                {
+                    line.Append(_completions[i]);
+
+                    int fill = AutoCompleteColumnLength - (line.Length % AutoCompleteColumnLength);
+                    line.Append(' ', fill);
+
+                    if (line.Length >= AutoCompleteColumns * AutoCompleteColumnLength)
+                    {
+                        Console.WriteLine(line.ToString());
+                        line.Clear();
+                    }
+                }
+
+                if (line.Length > 0)
+                {
+                    Console.WriteLine(line.ToString());
+                    line.Clear();
+                }
+            }
+            // display in lines
+            else
+            {
+                for (int i = 0; i < _completions.Length; i++)
+                {
+                    Console.WriteLine(_completions[i]);
+                }
+            }
+
+            _completions = null;
+            string prevText = _text.ToString();
+
+            // rewrite prompt and reset
+
+            ClearLine();
+            Console.WriteLine();
+            Console.Write(this.Prompt);
+            _cursorPos = 0;
+            _cursorLimit = 0;
+
+            // write previous string
+
+            WriteString(prevText);
+        }
+
         private void PrevHistory()
         {
             if (_historyIndex > 0)
@@ -269,7 +349,14 @@ public KeyHandler(IConsole console, List<string> history, Func<string, int, stri
                     if (_completions == null)
                         return;
 
-                    StartAutoComplete();
+                    if (this.RollingAutoComplete)
+                    {
+                        StartAutoComplete();
+                    }
+                    else
+                    {
+                        AllAutoComplete();
+                    }
                 }
             };
 

src/ReadLine/ReadLine.cs

@@ -13,19 +13,23 @@ public static class ReadLine
         static ReadLine()
         {
             _history = new List<string>();
+            RollingComplete = true;
         }
 
         public static void AddHistory(params string[] text) => _history.AddRange(text);
         public static List<string> GetHistory() => _history;
         public static void ClearHistory() => _history = new List<string>();
         public static Func<string, int, string[]> AutoCompletionHandler { private get; set; }
         public static bool PasswordMode { private get; set; }
+        public static bool RollingComplete { get; set; }
 
         public static string Read(string prompt = "", string defaultInput = "")
         {
             Console.Write(prompt);
 
             _keyHandler = new KeyHandler(new Console2() { PasswordMode = PasswordMode }, _history, AutoCompletionHandler);
+            _keyHandler.RollingAutoComplete = RollingComplete;
+            _keyHandler.Prompt = prompt;
             ConsoleKeyInfo keyInfo = Console.ReadKey(true);
 
             while (keyInfo.Key != ConsoleKey.Enter)