Remove set handler overloads

src/System.CommandLine.ApiCompatibility.Tests/ApiCompatibilityApprovalTests.System_CommandLine_api_is_not_changed.approved.txt

@@ -9,7 +9,7 @@ System.CommandLine
     public System.Collections.Generic.IEnumerable<System.CommandLine.Completions.CompletionItem> GetCompletions(System.CommandLine.Completions.CompletionContext context)
     public System.Object GetDefaultValue()
     public System.String ToString()
-  public class Argument<T> : Argument, IValueDescriptor<T>, System.CommandLine.Binding.IValueDescriptor
+  public class Argument<T> : Argument, System.CommandLine.Binding.IValueDescriptor
     .ctor(System.String name)
     public Func<System.CommandLine.Parsing.ArgumentResult,T> CustomParser { get; set; }
     public Func<System.CommandLine.Parsing.ArgumentResult,T> DefaultValueFactory { get; set; }
@@ -50,6 +50,8 @@ System.CommandLine
     public System.Collections.Generic.IEnumerator<Symbol> GetEnumerator()
     public ParseResult Parse(System.Collections.Generic.IReadOnlyList<System.String> args, CommandLineConfiguration configuration = null)
     public ParseResult Parse(System.String commandLine, CommandLineConfiguration configuration = null)
+    public System.Void SetHandler(System.Action<System.CommandLine.Invocation.InvocationContext> handle)
+    public System.Void SetHandler(System.Func<System.CommandLine.Invocation.InvocationContext,System.Threading.CancellationToken,System.Threading.Tasks.Task> handle)
   public static class CommandExtensions
     public static System.Int32 Invoke(this Command command, System.String[] args, IConsole console = null)
     public static System.Int32 Invoke(this Command command, System.String commandLine, IConsole console = null)
@@ -108,27 +110,6 @@ System.CommandLine
     public System.Void SetSynchronousHandler(System.Action<System.CommandLine.Invocation.InvocationContext> handler)
   public class EnvironmentVariablesDirective : Directive
     .ctor()
-  public static class Handler
-    public static System.Void SetHandler(this Command command, System.Action<System.CommandLine.Invocation.InvocationContext> handle)
-    public static System.Void SetHandler(this Command command, System.Action handle)
-    public static System.Void SetHandler(this Command command, System.Func<System.Threading.CancellationToken,System.Threading.Tasks.Task> handle)
-    public static System.Void SetHandler(this Command command, System.Func<System.CommandLine.Invocation.InvocationContext,System.Threading.CancellationToken,System.Threading.Tasks.Task> handle)
-    public static System.Void SetHandler<T>(this Command command, Action<T> handle, IValueDescriptor<T> symbol)
-    public static System.Void SetHandler<T>(this Command command, Func<T,System.Threading.CancellationToken,System.Threading.Tasks.Task> handle, IValueDescriptor<T> symbol)
-    public static System.Void SetHandler<T1, T2>(this Command command, Action<T1,T2> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2)
-    public static System.Void SetHandler<T1, T2>(this Command command, Func<T1,T2,System.Threading.CancellationToken,System.Threading.Tasks.Task> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2)
-    public static System.Void SetHandler<T1, T2, T3>(this Command command, Action<T1,T2,T3> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2, IValueDescriptor<T3> symbol3)
-    public static System.Void SetHandler<T1, T2, T3>(this Command command, Func<T1,T2,T3,System.Threading.CancellationToken,System.Threading.Tasks.Task> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2, IValueDescriptor<T3> symbol3)
-    public static System.Void SetHandler<T1, T2, T3, T4>(this Command command, Action<T1,T2,T3,T4> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2, IValueDescriptor<T3> symbol3, IValueDescriptor<T4> symbol4)
-    public static System.Void SetHandler<T1, T2, T3, T4>(this Command command, Func<T1,T2,T3,T4,System.Threading.CancellationToken,System.Threading.Tasks.Task> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2, IValueDescriptor<T3> symbol3, IValueDescriptor<T4> symbol4)
-    public static System.Void SetHandler<T1, T2, T3, T4, T5>(this Command command, Action<T1,T2,T3,T4,T5> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2, IValueDescriptor<T3> symbol3, IValueDescriptor<T4> symbol4, IValueDescriptor<T5> symbol5)
-    public static System.Void SetHandler<T1, T2, T3, T4, T5>(this Command command, Func<T1,T2,T3,T4,T5,System.Threading.CancellationToken,System.Threading.Tasks.Task> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2, IValueDescriptor<T3> symbol3, IValueDescriptor<T4> symbol4, IValueDescriptor<T5> symbol5)
-    public static System.Void SetHandler<T1, T2, T3, T4, T5, T6>(this Command command, Action<T1,T2,T3,T4,T5,T6> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2, IValueDescriptor<T3> symbol3, IValueDescriptor<T4> symbol4, IValueDescriptor<T5> symbol5, IValueDescriptor<T6> symbol6)
-    public static System.Void SetHandler<T1, T2, T3, T4, T5, T6>(this Command command, Func<T1,T2,T3,T4,T5,T6,System.Threading.CancellationToken,System.Threading.Tasks.Task> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2, IValueDescriptor<T3> symbol3, IValueDescriptor<T4> symbol4, IValueDescriptor<T5> symbol5, IValueDescriptor<T6> symbol6)
-    public static System.Void SetHandler<T1, T2, T3, T4, T5, T6, T7>(this Command command, Action<T1,T2,T3,T4,T5,T6,T7> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2, IValueDescriptor<T3> symbol3, IValueDescriptor<T4> symbol4, IValueDescriptor<T5> symbol5, IValueDescriptor<T6> symbol6, IValueDescriptor<T7> symbol7)
-    public static System.Void SetHandler<T1, T2, T3, T4, T5, T6, T7>(this Command command, Func<T1,T2,T3,T4,T5,T6,T7,System.Threading.CancellationToken,System.Threading.Tasks.Task> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2, IValueDescriptor<T3> symbol3, IValueDescriptor<T4> symbol4, IValueDescriptor<T5> symbol5, IValueDescriptor<T6> symbol6, IValueDescriptor<T7> symbol7)
-    public static System.Void SetHandler<T1, T2, T3, T4, T5, T6, T7, T8>(this Command command, Action<T1,T2,T3,T4,T5,T6,T7,T8> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2, IValueDescriptor<T3> symbol3, IValueDescriptor<T4> symbol4, IValueDescriptor<T5> symbol5, IValueDescriptor<T6> symbol6, IValueDescriptor<T7> symbol7, IValueDescriptor<T8> symbol8)
-    public static System.Void SetHandler<T1, T2, T3, T4, T5, T6, T7, T8>(this Command command, Func<T1,T2,T3,T4,T5,T6,T7,T8,System.Threading.CancellationToken,System.Threading.Tasks.Task> handle, IValueDescriptor<T1> symbol1, IValueDescriptor<T2> symbol2, IValueDescriptor<T3> symbol3, IValueDescriptor<T4> symbol4, IValueDescriptor<T5> symbol5, IValueDescriptor<T6> symbol6, IValueDescriptor<T7> symbol7, IValueDescriptor<T8> symbol8)
   public interface ICommandHandler
     public System.Int32 Invoke(System.CommandLine.Invocation.InvocationContext context)
     public System.Threading.Tasks.Task<System.Int32> InvokeAsync(System.CommandLine.Invocation.InvocationContext context, System.Threading.CancellationToken cancellationToken = null)
@@ -144,7 +125,7 @@ System.CommandLine
     public System.Collections.Generic.List<System.Action<System.CommandLine.Parsing.OptionResult>> Validators { get; }
     public System.Type ValueType { get; }
     public System.Collections.Generic.IEnumerable<System.CommandLine.Completions.CompletionItem> GetCompletions(System.CommandLine.Completions.CompletionContext context)
-  public class Option<T> : Option, IValueDescriptor<T>, System.CommandLine.Binding.IValueDescriptor
+  public class Option<T> : Option, System.CommandLine.Binding.IValueDescriptor
     .ctor(System.String name, System.String[] aliases)
     public Func<System.CommandLine.Parsing.ArgumentResult,T> CustomParser { get; set; }
     public Func<System.CommandLine.Parsing.ArgumentResult,T> DefaultValueFactory { get; set; }
@@ -191,8 +172,6 @@ System.CommandLine
     public System.Collections.Generic.IEnumerable<System.CommandLine.Completions.CompletionItem> GetCompletions(System.CommandLine.Completions.CompletionContext context)
     public System.String ToString()
 System.CommandLine.Binding
-  public abstract class BinderBase<T>, IValueDescriptor<T>, IValueDescriptor, IValueSource
-    protected T GetBoundValue(BindingContext bindingContext)
   public class BindingContext, System.IServiceProvider
     public System.CommandLine.IConsole Console { get; }
     public System.CommandLine.ParseResult ParseResult { get; }
@@ -209,7 +188,6 @@ System.CommandLine.Binding
     public System.String ValueName { get; }
     public System.Type ValueType { get; }
     public System.Object GetDefaultValue()
-  public interface IValueDescriptor<out T> : IValueDescriptor
   public interface IValueSource
     public System.Boolean TryGetValue(IValueDescriptor valueDescriptor, BindingContext bindingContext, ref System.Object& boundValue)
 System.CommandLine.Completions

src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Simple.cs

@@ -33,7 +33,11 @@ private static RootCommand BuildCommand()
                 stringOption
             };
 
-            command.SetHandler(static (bool _, string _) => { }, boolOption, stringOption);
+            command.SetHandler(ctx => 
+            {
+                bool boolean = ctx.ParseResult.GetValue(boolOption);
+                string text = ctx.ParseResult.GetValue(stringOption);
+            });
 
             return command;
         }

src/System.CommandLine.Suggest.Tests/EndToEndTestApp/Program.cs

@@ -1,4 +1,5 @@
 using System.CommandLine;
+using System.CommandLine.Invocation;
 using System.CommandLine.Parsing;
 using System.Threading.Tasks;
 using System.Threading;
@@ -22,12 +23,15 @@ static async Task Main(string[] args)
                 durianOption,          
             };
 
-            rootCommand.SetHandler(
-                (string apple, string banana, string cherry, string durian, CancellationToken cancellationToken) => Task.CompletedTask,
-                appleOption,
-                bananaOption,
-                cherryOption,
-                durianOption);
+            rootCommand.SetHandler((InvocationContext ctx, CancellationToken cancellationToken) =>
+            {
+                string apple = ctx.ParseResult.GetValue(appleOption);
+                string banana = ctx.ParseResult.GetValue(bananaOption);
+                string cherry = ctx.ParseResult.GetValue(cherryOption);
+                string durian = ctx.ParseResult.GetValue(durianOption);
+
+                return Task.CompletedTask;
+            });
 
             var commandLine = new CommandLineBuilder(rootCommand)
                 .UseDefaults()

src/System.CommandLine.Tests/ArgumentTests.cs

@@ -378,7 +378,7 @@ public async Task Custom_argument_parser_is_only_called_once()
                 };
 
                 var command = new RootCommand();
-                command.SetHandler((int value) => handlerWasCalled = true, option);
+                command.SetHandler((ctx) => handlerWasCalled = true);
                 command.Options.Add(option);
 
                 await command.InvokeAsync("--value 42");