Initial commit

.gitignore

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+## Ignore Visual Studio temporary files, build results, and
+## files generated by popular Visual Studio add-ons.
+##
+## Get latest from https://github.com/github/gitignore/blob/master/VisualStudio.gitignore
+
+# User-specific files
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+# Visual Studio 2015/2017 cache/options directory
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+project.lock.json
+project.fragment.lock.json
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+# ASP.NET Scaffolding
+ScaffoldingReadMe.txt
+
+# StyleCop
+StyleCopReport.xml
+
+# Files built by Visual Studio
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+# Visual Studio profiler
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+# Visual Studio Trace Files
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+# DotCover is a Code Coverage Tool
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+
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+!.axoCover/settings.json
+
+# Coverlet is a free, cross platform Code Coverage Tool
+coverage*[.json, .xml, .info]
+
+# Visual Studio code coverage results
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+# NCrunch
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+.*crunch*.local.xml
+nCrunchTemp_*
+
+# MightyMoose
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+
+# Web workbench (sass)
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+# Note: Comment the next line if you want to checkin your web deploy settings,
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+# except build/, which is used as an MSBuild target.
+!**/[Pp]ackages/build/
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+#!**/[Pp]ackages/repositories.config
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+# Including strong name files can present a security risk
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+# Since there are multiple workflows, uncomment next line to ignore bower_components
+# (https://github.com/github/gitignore/pull/1529#issuecomment-104372622)
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+# RIA/Silverlight projects
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+# because we have git ;-)
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+*- [Bb]ackup.rdl
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+
+# Microsoft Fakes
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+
+# GhostDoc plugin setting file
+*.GhostDoc.xml
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+# Node.js Tools for Visual Studio
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+node_modules/
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+
+# Paket dependency manager
+.paket/paket.exe
+paket-files/
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+.fake/
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+# CodeRush personal settings
+.cr/personal
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+# Python Tools for Visual Studio (PTVS)
+__pycache__/
+*.pyc
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+# Cake - Uncomment if you are using it
+# tools/**
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+.ionide/
+
+# Fody - auto-generated XML schema
+FodyWeavers.xsd

termsync.sln

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+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.29609.76
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "termsync", "termsync\termsync.csproj", "{2CBA290C-FF91-4825-B96B-83A0F9151F9E}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "test", "test\test.csproj", "{B4D9D0D8-C63A-479A-8443-48CCBFBB1C56}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{2CBA290C-FF91-4825-B96B-83A0F9151F9E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{2CBA290C-FF91-4825-B96B-83A0F9151F9E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{2CBA290C-FF91-4825-B96B-83A0F9151F9E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{2CBA290C-FF91-4825-B96B-83A0F9151F9E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B4D9D0D8-C63A-479A-8443-48CCBFBB1C56}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B4D9D0D8-C63A-479A-8443-48CCBFBB1C56}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B4D9D0D8-C63A-479A-8443-48CCBFBB1C56}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B4D9D0D8-C63A-479A-8443-48CCBFBB1C56}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {E035A5E5-8125-44B3-8F69-557971CAFB19}
+	EndGlobalSection
+EndGlobal

termsync/AsyncTools.cs

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+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Linq;
+using System.Collections.Generic;
+
+namespace termsync.Tools
+{
+    sealed class AsyncMutex : IDisposable
+    {
+        private readonly SemaphoreSlim sem;
+
+        public AsyncMutex()
+        {
+            sem = new SemaphoreSlim(1, 1);
+        }
+        private AsyncMutex(SemaphoreSlim from)
+        {
+            sem = from;
+        }
+
+        private class Lock : IDisposable
+        {
+            public AsyncMutex Parent { get; }
+            public Lock(AsyncMutex held)
+            {
+                Parent = held;
+            }
+
+            public void Dispose()
+            {
+                Parent.sem.Release();
+            }
+        }
+
+        public IDisposable Acquire(int msTimeout, CancellationToken token = default)
+        {
+            sem.Wait(msTimeout, token);
+            return new Lock(this);
+        }
+
+        public IDisposable Acquire(CancellationToken token)
+        {
+            sem.Wait(token);
+            return new Lock(this);
+        }
+
+        public IDisposable Acquire()
+        {
+            sem.Wait();
+            return new Lock(this);
+        }
+
+        public async Task<IDisposable> AcquireAsync(int msTimeout, CancellationToken token = default)
+        {
+            await sem.WaitAsync(msTimeout, token);
+            return new Lock(this);
+        }
+
+        public async Task<IDisposable> AcquireAsync(CancellationToken token = default)
+        {
+            await sem.WaitAsync(token);
+            return new Lock(this);
+        }
+
+        public void Dispose()
+        {
+            sem.Dispose();
+        }
+
+        public static AsyncMutex Semaphore(int count, int max)
+        {
+            SemaphoreSlim sem = new SemaphoreSlim(count, max);
+            return new AsyncMutex(sem);
+        }
+        public static AsyncMutex Semaphore(int count)
+         => Semaphore(count, count);
+    }
+
+    static class ExAsyncTools
+    {
+        #region Then()
+        public static async Task Then(this Task t, Action lam)
+        {
+            await t;
+            lam();
+        }
+        public static Task Then(this Task t, Action lam, CancellationToken token)
+            => Then(t, (_) => lam(), token);
+        public static async Task Then(this Task t, Action<CancellationToken> lam, CancellationToken token)
+        {
+            TaskCompletionSource<bool> fail = new TaskCompletionSource<bool>();
+
+            using (token.Register(() => fail.TrySetResult(false)))
+            {
+                if ((await Task.WhenAny(t, fail.Task)) == t)
+                {
+                    lam(token);
+                }
+                token.ThrowIfCancellationRequested();
+            }
+        }
+        public static async Task Then(this Task t, Func<Task> lam)
+        {
+            await t;
+            await lam();
+        }
+        public static Task Then(this Task t, Func<Task> lam, CancellationToken token)
+            => Then(t, (_) => lam(), token);
+        public static async Task Then(this Task t, Func<CancellationToken, Task> lam, CancellationToken token)
+        {
+            TaskCompletionSource<bool> fail = new TaskCompletionSource<bool>();
+
+            using (token.Register(() => fail.TrySetResult(false)))
+            {
+                if ((await Task.WhenAny(t, fail.Task)) == t)
+                {
+                    await lam(token);
+                }
+                token.ThrowIfCancellationRequested();
+            }
+        }
+        public static async Task<T> Then<T>(this Task<T> t, Action<T> lam)
+        {
+            T res = await t;
+            lam(res);
+            return res;
+        }
+        public static Task<T> Then<T>(this Task<T> t, Action<T> lam, CancellationToken token)
+            => Then(t, (v, _) => lam(v), token);
+        public static async Task<T> Then<T>(this Task<T> t, Action<T, CancellationToken> lam, CancellationToken token)
+        {
+            TaskCompletionSource<bool> fail = new TaskCompletionSource<bool>();
+
+            using (token.Register(() => fail.TrySetResult(false)))
+            {
+                if ((await Task.WhenAny(t, fail.Task)) == t)
+                {
+                    var res = t.Result;
+                    lam(res, token);
+                    return res;
+                }
+                throw new OperationCanceledException();
+            }
+        }
+        public static async Task<T> Then<T>(this Task<T> t, Func<T, T> lam)
+        {
+            T res = await t;
+            return lam(res);
+        }
+        public static Task<T> Then<T>(this Task<T> t, Func<T, T> lam, CancellationToken token)
+            => Then(t, (v, _) => lam(v), token);
+        public static async Task<T> Then<T>(this Task<T> t, Func<T, CancellationToken, T> lam, CancellationToken token)
+        {
+            TaskCompletionSource<bool> fail = new TaskCompletionSource<bool>();
+
+            using (token.Register(() => fail.TrySetResult(false)))
+            {
+                if ((await Task.WhenAny(t, fail.Task)) == t)
+                {
+                    var res = t.Result;
+                    res = lam(res, token);
+                    return res;
+                }
+                throw new OperationCanceledException();
+            }
+        }
+        public static async Task<T> Then<T>(this Task<T> t, Func<T, Task<T>> lam)
+        {
+            return await lam(await t);
+        }
+        public static Task<T> Then<T>(this Task<T> t, Func<T, Task<T>> lam, CancellationToken token)
+            => Then(t, (x, _) => lam(x), token);
+        public static async Task<T> Then<T>(this Task<T> t, Func<T, CancellationToken, Task<T>> lam, CancellationToken token)
+        {
+            TaskCompletionSource<bool> fail = new TaskCompletionSource<bool>();
+
+            using (token.Register(() => fail.TrySetResult(false)))
+            {
+                if ((await Task.WhenAny(t, fail.Task)) == t)
+                {
+                    var res = t.Result;
+                    res = await lam(res, token);
+                    return res;
+                }
+                throw new OperationCanceledException();
+            }
+        }
+        #endregion
+
+        public static CancellationTokenSource Link(this in CancellationToken token, params CancellationToken[] others)
+        {
+            return CancellationTokenSource.CreateLinkedTokenSource(new CancellationToken[] { token }.Concat(others).ToArray());
+        }
+
+
+    }
+
+
+}

termsync/Control.cs

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+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace termsync
+{
+    enum DeleteLocation
+    {
+        Before, //Backspace
+        After, //DEL
+    }
+    enum MoveDirection
+    {
+        Left,Right,
+    }
+    enum ControlType
+    {
+        Print, //WriteLine
+
+        Move, //Move the cursor
+        Delete, //Delete a character from input
+        Commit, //Commit input
+        Echo, // Add a character to input
+
+        ChangePrompt,
+    }
+    readonly struct ControlValue
+    {
+        public readonly ControlType Type;
+
+        public readonly object Value;
+
+        public readonly TaskCompletionSource<object> Processed;
+
+        public ControlValue(ControlType type, object value)
+        {
+            Type = type;
+            Value = value;
+
+            Processed = new TaskCompletionSource<object>();
+        }
+    }
+}

termsync/Mutations.cs

@@ -0,0 +1,58 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Threading;
+using System.Threading.Channels;
+using System.Threading.Tasks;
+
+namespace termsync
+{
+    static partial class Terminal
+    {
+        private static class Mutation
+        {
+            public static void ClearInputBuffer()
+            {
+                Console.CursorLeft = 0;
+                Console.Write(new string(' ', Console.WindowWidth - 1));
+                Console.CursorLeft = 0;
+            }
+
+            public static void RedrawInputBuffer(bool prompt=true)
+            {
+                if(prompt)
+                    Console.Write(Prompt);
+
+                if (InputBuffer.Count > 0)
+                    Console.Write(InputBuffer.ToArray());
+                if (InputAt > -1)
+                    Console.CursorLeft -= InputBuffer.Count - InputAt;
+            }
+
+            public static void MoveBackOne()
+            {
+                Console.MoveBufferArea(Console.CursorLeft + 1, Console.CursorTop, InputBuffer.Count - InputAt, 1, Console.CursorLeft, Console.CursorTop);
+            }
+            public static void MoveForwardOne()
+            {
+                Console.MoveBufferArea(Console.CursorLeft, Console.CursorTop, InputBuffer.Count - InputAt, 1, Console.CursorLeft + 1, Console.CursorTop);
+            }
+
+            public static async Task FlushAsync(ChannelWriter<string> lines, CancellationToken token =default)
+            {
+                ClearInputBuffer();
+                var inp = new string(InputBuffer.ToArray());
+                var line_send= lines.WriteAsync(inp, token);
+                InputBuffer.Clear();
+                InputAt = -1;
+
+                RedrawInputBuffer();
+
+                if (WriteLineOnFlush)
+                    await WriteLine(Prompt + inp, token);
+
+                await line_send;
+            }
+        }
+    }
+}

termsync/Terminal.cs

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+using System;
+using System.Threading.Tasks;
+using System.Threading;
+using System.Threading.Channels;
+
+using termsync.Tools;
+using System.Collections.Generic;
+
+namespace termsync
+{
+    /// <summary>
+    /// A Write container that aquires a mutex on `Terminal`, preventing other writes while held.
+    /// </summary>
+    public sealed class TermLock : IDisposable
+    {
+        private readonly CancellationTokenSource cancel;
+        private readonly AsyncMutex GlobalMutex;
+        private IDisposable held_lock = null;
+        internal TermLock(AsyncMutex mutex, CancellationToken token=default)
+        {
+            GlobalMutex = mutex;
+
+            cancel = CancellationTokenSource.CreateLinkedTokenSource(token);
+        }
+
+        internal async Task Acquire()
+        {
+            held_lock = await GlobalMutex.AcquireAsync(cancel.Token);
+        }
+
+        /// <summary>
+        /// Write a line with lock held.
+        /// </summary>
+        public Task WriteLine(string line)
+        {
+            return Terminal.WriteLineAndWait(line, cancel.Token);
+        }
+
+        public void Dispose()
+        {
+            cancel.Cancel();
+            cancel.Dispose();
+            if(held_lock!=null)
+            {
+                held_lock.Dispose();
+                held_lock = null;
+            }
+        }
+
+        ~TermLock()
+        {
+            if (held_lock != null)
+            {
+                held_lock.Dispose();
+                held_lock = null;
+            }
+        }
+    }
+
+    public sealed class TermStage : IAsyncDisposable
+    {
+        private readonly AsyncMutex mutex = new AsyncMutex();
+        private readonly List<string> lines = new List<string>();
+        private readonly CancellationTokenSource cancel;
+        private readonly AsyncMutex globalMutex;
+        private readonly CancellationToken originalToken;
+
+        internal TermStage(AsyncMutex globalM, CancellationToken token)
+        {
+            originalToken = token;
+            globalMutex = globalM;
+            cancel = CancellationTokenSource.CreateLinkedTokenSource(token);
+        }
+
+        public async Task WriteLine(string line)
+        {
+            using (await mutex.AcquireAsync(cancel.Token))
+            {
+                lines.Add(line);
+            }
+        }
+
+        public async ValueTask DisposeAsync()
+        {
+            await mutex.AcquireAsync(cancel.Token);
+
+            cancel.Cancel();
+
+            mutex.Dispose();
+            cancel.Dispose();
+
+            using (await globalMutex.AcquireAsync(originalToken))
+            {
+                foreach (var line in lines)
+                {
+                    await Terminal.WriteLineAndWait(line, originalToken);
+                }
+            }
+
+            lines.Clear();
+        }
+    }
+
+    //TODO: WriteLine staging that doesn't block until read to commit all.
+
+    /// <summary>
+    /// Terminal control global state.
+    /// </summary>
+    public static partial class Terminal
+    {
+        #region Sync
+        private static readonly CancellationTokenSource CancelAll = new CancellationTokenSource();
+        private static ChannelReader<string> Input;
+        private static ChannelWriter<ControlValue> Output;
+
+        private static readonly AsyncMutex ConsoleMutex = new AsyncMutex();
+
+        #endregion
+        #region Buffer
+        private static readonly List<char> InputBuffer = new List<char>();
+        /// <summary>
+        /// The place in the <see cref="InputBuffer"/> that the user is writing to.
+        /// </summary>
+        private static int InputAt = -1;
+        public static string Prompt { get; private set; } = "> ";
+        private static bool WriteLineOnFlush = true;
+
+        #endregion
+
+        #region Control
+        private static readonly AsyncMutex UserWriteMutex = new AsyncMutex();
+        private static readonly AsyncMutex UserReadMutex = new AsyncMutex();
+
+        /// <summary>
+        /// Acquire global Write lock mutex.
+        /// </summary>
+        public static async Task<TermLock> Lock()
+        {
+            var l = new TermLock(UserWriteMutex, CancelAll.Token);
+            await l.Acquire();
+            return l;
+        }
+
+        /// <summary>
+        /// Create a staging container that will write all lines at once on DisposeAsync().
+        /// </summary>
+        public static TermStage Stage()
+        {
+            return new TermStage(UserWriteMutex, CancelAll.Token);
+        }
+
+        private static async Task<object> SendAndWait(ControlValue value, CancellationToken token = default)
+        {
+            TaskCompletionSource<bool> onCancel = new TaskCompletionSource<bool>();
+            using var reg = token.Register(() =>
+            {
+                onCancel.SetResult(false);
+            });
+            await Output.WriteAsync(value, token);
+
+
+            if (await Task.WhenAny(value.Processed.Task, onCancel.Task) == value.Processed.Task)
+            {
+                return value.Processed.Task.Result;
+            }
+            else throw new OperationCanceledException();
+        }
+        /// <summary>
+        /// Write a line to the Terminal and wait for it to appear.
+        /// </summary>
+        /// <param name="line">The line</param>
+        public static async Task WriteLine(string line)
+        {
+            using(await UserWriteMutex.AcquireAsync(CancelAll.Token))
+            {
+                await SendAndWait(new ControlValue(ControlType.Print, line), CancelAll.Token);
+            }
+        }
+        internal static ValueTask WriteLine(string str, CancellationToken token)
+        {
+            return Output.WriteAsync(new ControlValue(ControlType.Print, str), token);
+        }
+        internal static Task WriteLineAndWait(string str, CancellationToken token)
+        {
+            return SendAndWait(new ControlValue(ControlType.Print, str), token);
+        }
+
+        /// <summary>
+        /// Read a line from the user.
+        /// </summary>
+        public static async Task<string> ReadLine(CancellationToken token=default)
+        {
+            using var cancel = CancellationTokenSource.CreateLinkedTokenSource(CancelAll.Token, token);
+            token = cancel.Token;
+
+            using (await UserReadMutex.AcquireAsync(token))
+            {
+               return await Input.ReadAsync(token);
+            }
+        }
+
+        /// <summary>
+        /// Change the user prompt.
+        /// </summary>
+        /// <param name="prompt">New prompt.</param>
+        public static async Task ChangePrompt(string prompt)
+        {
+            using (await UserWriteMutex.AcquireAsync(CancelAll.Token))
+            {
+                await SendAndWait(new ControlValue(ControlType.ChangePrompt, prompt), CancelAll.Token);
+            }
+        }
+
+        #endregion
+
+        /// <summary>
+        /// Initialise terminal control. Writes go through <see cref="Terminal"/> after this.
+        /// </summary>
+        /// <returns>The control task.</returns>
+        public static Task Initialise()
+        {
+
+            var input = Channel.CreateUnbounded<string>();
+            var output = Channel.CreateBounded<ControlValue>(10);
+
+            Input = input.Reader;
+            Output = output.Writer;
+
+            AppDomain.CurrentDomain.ProcessExit += (_, __) => Cleanup();
+            var t_output = Task.Run(async () =>
+            {
+                try
+                {
+                    await ctrl_output(output.Reader, input.Writer);
+                }
+                catch (OperationCanceledException) { }
+                catch (Exception ex)
+                {
+                    if (!CancelAll.IsCancellationRequested)
+                        CancelAll.Cancel();
+                }
+            });
+
+            var t_input = Task.Run(async () =>
+            {
+                try
+                {
+                    await ctrl_intput();
+                }
+                catch (OperationCanceledException) { }
+                catch (Exception ex)
+                {
+                    if(!CancelAll.IsCancellationRequested)
+                    CancelAll.Cancel();
+                }
+            });
+
+            return Task.Run(async () =>
+            {
+                await Task.WhenAll(t_input, t_output);
+            });
+        }
+
+        private static async Task ctrl_output(ChannelReader<ControlValue> output, ChannelWriter<string> lines)
+        {
+            await foreach(var value in output.ReadAllAsync(CancelAll.Token))
+            {
+                object result = null;
+                try
+                {
+                    switch (value.Type)
+                    {
+                        case ControlType.Print when value.Value is string line:
+                            using (await ConsoleMutex.AcquireAsync(CancelAll.Token))
+                            {
+                                Mutation.ClearInputBuffer();
+                                Console.WriteLine(line);
+                                Mutation.RedrawInputBuffer();
+                            }
+                            break;
+                        case ControlType.Move:
+                            using (await ConsoleMutex.AcquireAsync(CancelAll.Token))
+                            {
+                                if (InputAt == -1) InputAt = InputBuffer.Count;
+                                switch ((MoveDirection)value.Value)
+                                {
+                                    case MoveDirection.Left:
+                                        if (InputAt > 0)
+                                        {
+                                            InputAt -= 1;
+                                            Console.CursorLeft -= 1;
+                                        }
+                                        break;
+                                    case MoveDirection.Right:
+                                        if (InputAt < InputBuffer.Count)
+                                        {
+                                            InputAt += 1;
+                                            Console.CursorLeft += 1;
+                                        }
+                                        break;
+                                }
+                                if (InputAt >= InputBuffer.Count)
+                                    InputAt = -1;
+                            }
+                            break;
+                        case ControlType.Delete:
+                            using (await ConsoleMutex.AcquireAsync(CancelAll.Token))
+                            {
+                                switch ((DeleteLocation)value.Value)
+                                {
+                                    case DeleteLocation.After:
+                                        if (InputBuffer.Count > 0)
+                                        {
+                                            if (InputAt >= 0 && InputAt < InputBuffer.Count)
+                                            {
+                                                InputBuffer.RemoveAt(InputAt);
+
+                                                Console.Write(" \b");
+                                                Mutation.MoveBackOne();
+                                            }
+                                        }
+                                        break;
+                                    case DeleteLocation.Before:
+                                        if (InputBuffer.Count > 0)
+                                        {
+                                            if (InputAt > 0 && InputAt < InputBuffer.Count)
+                                            {
+                                                InputBuffer.RemoveAt(InputAt - 1);
+                                                InputAt -= 1;
+
+                                                Console.Write("\b");
+                                                Mutation.MoveBackOne();
+                                            }
+                                            else if (InputAt != 0)
+                                            {
+                                                InputBuffer.RemoveAt(InputBuffer.Count - 1);
+                                                Console.Write("\b \b");
+                                            }
+                                        }
+                                        break;
+                                }
+                            }
+                            break;
+                        case ControlType.Commit:
+                            using (await ConsoleMutex.AcquireAsync(CancelAll.Token))
+                            {
+                                await Mutation.FlushAsync(lines, CancelAll.Token);
+                            }
+                            break;
+                        case ControlType.Echo:
+                            using (await ConsoleMutex.AcquireAsync(CancelAll.Token))
+                            {
+                                var input = value.Value as string;
+                                if (input == null) continue;
+                                for (int i = 0; i < input.Length; i++)
+                                {
+                                    switch (input[i])
+                                    {
+                                        case '\n':
+                                        case '\r':
+                                            //Should be handled by `Commit`, something went wrong if they end up here.
+                                            break;
+                                        case '\b':
+                                            //Ditto for `Delete`.
+                                            break;
+                                        default:
+                                            {
+                                                if (((InputAt == -1) ? Console.CursorLeft : Console.CursorLeft + (InputBuffer.Count - InputAt)) >= Console.BufferWidth - 1) break; //TODO: Scrolling buffer?
+
+                                                if (InputAt >= 0 && InputAt < InputBuffer.Count)
+                                                {
+                                                    InputBuffer.Insert(InputAt, input[i]);
+                                                    InputAt += 1;
+
+                                                    Mutation.MoveForwardOne();
+                                                }
+                                                else
+                                                {
+                                                    InputBuffer.Add(input[i]);
+                                                }
+                                                Console.Write(input[i]);
+                                            }
+                                            break;
+                                    }
+                                }
+                            }
+                            break;
+                        case ControlType.ChangePrompt:
+                            using (await ConsoleMutex.AcquireAsync(CancelAll.Token))
+                            {
+                                Prompt = (string)value.Value;
+
+                                Mutation.ClearInputBuffer();
+                                Mutation.RedrawInputBuffer();
+                            }
+                            break;
+                    }
+                }
+                finally
+                {
+                    value.Processed.SetResult(result);
+                }
+            }
+
+            lines.Complete();
+            InputBuffer.Clear();
+        }
+        /// <summary>
+        /// Read from the Console and pipe buffer control events to `Output`.
+        /// </summary>
+        private static async Task ctrl_intput()
+        {
+            while (!CancelAll.IsCancellationRequested)
+            {
+                var key = Console.ReadKey(true); // This blocks.
+
+                if (CancelAll.IsCancellationRequested) break;
+                switch (key.Key)
+                {
+                    case ConsoleKey.LeftArrow:
+                        await Output.WriteAsync(new ControlValue(ControlType.Move, MoveDirection.Left), CancelAll.Token);
+
+                        break;
+                    case ConsoleKey.RightArrow:
+                        await Output.WriteAsync(new ControlValue(ControlType.Move, MoveDirection.Right), CancelAll.Token);
+
+                        break;
+                    case ConsoleKey.Delete:
+                        await Output.WriteAsync(new ControlValue(ControlType.Delete, DeleteLocation.After), CancelAll.Token);
+                        break;
+                    case ConsoleKey.Backspace:
+                        await Output.WriteAsync(new ControlValue(ControlType.Delete, DeleteLocation.Before), CancelAll.Token);
+                        break;
+                    case ConsoleKey.Enter:
+                        await Output.WriteAsync(new ControlValue(ControlType.Commit, null), CancelAll.Token);
+                        break;
+                    default:
+                        await Output.WriteAsync(new ControlValue(ControlType.Echo, new string(new[] { key.KeyChar })), CancelAll.Token);
+                        break;
+                }
+
+            }
+        }
+
+        /// <summary>
+        /// Close all <see cref="Terminal"/> channels.
+        /// </summary>
+        public static void Close()
+        {
+            Output.Complete();
+        }
+        private static void Cleanup()
+        {
+            try
+            {
+                Output.Complete();
+            }
+            catch { }
+            if (!CancelAll.IsCancellationRequested)
+                CancelAll.Cancel();
+
+            CancelAll.Dispose();
+            ConsoleMutex.Dispose();
+        }
+    }
+}

termsync/termsync.csproj

@@ -0,0 +1,7 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+  </PropertyGroup>
+
+</Project>

test/Program.cs

@@ -0,0 +1,47 @@
+using System;
+using System.Threading.Tasks;
+using termsync;
+
+namespace test
+{
+    class Program
+    {
+        static async Task Main(string[] args)
+        {
+            _ = Terminal.Initialise();
+
+            await Terminal.WriteLine("Hiya!");
+            await Terminal.WriteLine("Another line...");
+            var line = await Terminal.ReadLine();
+            await Terminal.WriteLine("Line: " + line);
+
+            await Task.WhenAll(Task.Run(async () =>
+            {
+                await using (var stage = Terminal.Stage())
+                {
+                    await stage.WriteLine("One line");
+                    await stage.WriteLine("Two line");
+                    await stage.WriteLine("Three line");
+                    await stage.WriteLine("Four");
+                }
+            }),
+            Task.Run(async () =>
+            {
+                using (var lck = await Terminal.Lock())
+                {
+                    await lck.WriteLine("One line locked");
+                    await lck.WriteLine("Two line locked");
+                    await lck.WriteLine("Three line locked");
+                    await lck.WriteLine("Four locked");
+                }
+            }));
+
+            await Terminal.ChangePrompt("USER> " + await Terminal.ReadLine()+":: ");
+
+            await Terminal.WriteLine("New prompt!");
+            await Terminal.ReadLine();
+
+            Terminal.Close();
+        }
+    }
+}

test/test.csproj

@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\termsync\termsync.csproj" />
+  </ItemGroup>
+
+</Project>