Name and aliases separation

src/Common/ArgumentBuilder.cs

@@ -9,7 +9,7 @@ internal static class ArgumentBuilder
 
     static ArgumentBuilder()
     {
-        _ctor = typeof(Argument<string>).GetConstructor(new[] { typeof(string), typeof(string) });
+        _ctor = typeof(Argument<string>).GetConstructor(new[] { typeof(string) });
     }
 
     public static Argument CreateArgument(Type valueType, string name = "value")
@@ -19,10 +19,10 @@ public static Argument CreateArgument(Type valueType, string name = "value")
 #if NET6_0_OR_GREATER
         var ctor = (ConstructorInfo)argumentType.GetMemberWithSameMetadataDefinitionAs(_ctor);
 #else
-        var ctor = argumentType.GetConstructor(new[] { typeof(string), typeof(string) });
+        var ctor = argumentType.GetConstructor(new[] { typeof(string) });
 #endif
 
-        return (Argument)ctor.Invoke(new object[] { name, null });
+        return (Argument)ctor.Invoke(new object[] { name });
     }
 
     internal static Argument CreateArgument(ParameterInfo argsParam)
@@ -32,10 +32,20 @@ internal static Argument CreateArgument(ParameterInfo argsParam)
             return CreateArgument(argsParam.ParameterType, argsParam.Name);
         }
 
-        var argumentType = typeof(Argument<>).MakeGenericType(argsParam.ParameterType);
+        var argumentType = typeof(Bridge<>).MakeGenericType(argsParam.ParameterType);
 
-        var ctor = argumentType.GetConstructor(new[] { typeof(string), argsParam.ParameterType, typeof(string) });
+        var ctor = argumentType.GetConstructor(new[] { typeof(string), argsParam.ParameterType });
 
-        return (Argument)ctor.Invoke(new object[] { argsParam.Name, argsParam.DefaultValue, null });
+        return (Argument)ctor.Invoke(new object[] { argsParam.Name, argsParam.DefaultValue });
+    }
+
+    private sealed class Bridge<T> : Argument<T>
+    {
+        public Bridge(string name, T defaultValue)
+            : base(name)
+        {
+            // this type exists only for an easy T => Func<ArgumentResult, T> transformation
+            DefaultValueFactory = (_) => defaultValue;
+        }
     }
 }

src/Common/OptionBuilder.cs

@@ -11,25 +11,27 @@ internal static class OptionBuilder
 
     static OptionBuilder()
     {
-        _ctor = typeof(Option<string>).GetConstructor(new[] { typeof(string), typeof(string) });
+        _ctor = typeof(Option<string>).GetConstructor(new[] { typeof(string), typeof(string[]) });
     }
 
-    public static Option CreateOption(string name, Type valueType, string description = null)
+    internal static Option CreateOption(string name, Type valueType, string description = null)
     {
         var optionType = typeof(Option<>).MakeGenericType(valueType);
 
 #if NET6_0_OR_GREATER
         var ctor = (ConstructorInfo)optionType.GetMemberWithSameMetadataDefinitionAs(_ctor);
 #else
-        var ctor = optionType.GetConstructor(new[] { typeof(string), typeof(string) });
+        var ctor = optionType.GetConstructor(new[] { typeof(string), typeof(string[]) });
 #endif
 
-        var option = (Option)ctor.Invoke(new object[] { name, description });
+        var option = (Option)ctor.Invoke(new object[] { name, Array.Empty<string>() });
+
+        option.Description = description;
 
         return option;
     }
 
-    public static Option CreateOption(string name, Type valueType, string description, Func<object> defaultValueFactory)
+    internal static Option CreateOption(string name, Type valueType, string description, Func<object> defaultValueFactory)
     {
         if (defaultValueFactory == null)
         {
@@ -45,13 +47,14 @@ public static Option CreateOption(string name, Type valueType, string descriptio
         return option;
     }
 
-    private class Bridge<T> : Option<T>
+    private sealed class Bridge<T> : Option<T>
     {
         public Bridge(string name, Func<object> defaultValueFactory, string description)
-            : base(name, 
-                  () => (T)defaultValueFactory(), // this type exists only for an easy Func<object> => Func<T> transformation
-                  description)
+            : base(name)
         {
+            // this type exists only for an easy Func<object> => Func<T> transformation
+            DefaultValueFactory = (_) => (T)defaultValueFactory();
+            Description = description;
         }
     }
 }

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

@@ -10,21 +10,14 @@ System.CommandLine
     public System.Object GetDefaultValue()
     public System.String ToString()
   public class Argument<T> : Argument, IValueDescriptor<T>, System.CommandLine.Binding.IValueDescriptor
-    .ctor()
-    .ctor(System.String name, System.String description = null)
-    .ctor(System.String name, Func<T> defaultValueFactory, System.String description = null)
-    .ctor(System.String name, T defaultValue, System.String description = null)
-    .ctor(Func<T> defaultValueFactory)
-    .ctor(System.String name, Func<System.CommandLine.Parsing.ArgumentResult,T> parse, System.Boolean isDefault = False, System.String description = null)
-    .ctor(Func<System.CommandLine.Parsing.ArgumentResult,T> parse, System.Boolean isDefault = False)
+    .ctor(System.String name)
+    public Func<System.CommandLine.Parsing.ArgumentResult,T> CustomParser { get; set; }
+    public Func<System.CommandLine.Parsing.ArgumentResult,T> DefaultValueFactory { get; set; }
     public System.Boolean HasDefaultValue { get; }
     public System.Type ValueType { get; }
     public System.Void AcceptLegalFileNamesOnly()
     public System.Void AcceptLegalFilePathsOnly()
     public System.Void AcceptOnlyFromAmong(System.String[] values)
-    public System.Void SetDefaultValue(T value)
-    public System.Void SetDefaultValueFactory(Func<T> defaultValueFactory)
-    public System.Void SetDefaultValueFactory(Func<System.CommandLine.Parsing.ArgumentResult,T> defaultValueFactory)
   public struct ArgumentArity : System.ValueType, System.IEquatable<ArgumentArity>
     public static ArgumentArity ExactlyOne { get; }
     public static ArgumentArity OneOrMore { get; }
@@ -42,8 +35,9 @@ System.CommandLine
     public static Argument<System.IO.DirectoryInfo> AcceptExistingOnly(this Argument<System.IO.DirectoryInfo> argument)
     public static Argument<System.IO.FileSystemInfo> AcceptExistingOnly(this Argument<System.IO.FileSystemInfo> argument)
     public static Argument<T> AcceptExistingOnly<T>(this Argument<T> argument)
-  public class Command : IdentifierSymbol, System.Collections.Generic.IEnumerable<Symbol>, System.Collections.IEnumerable
+  public class Command : Symbol, System.Collections.Generic.IEnumerable<Symbol>, System.Collections.IEnumerable
     .ctor(System.String name, System.String description = null)
+    public System.Collections.Generic.ICollection<System.String> Aliases { get; }
     public System.Collections.Generic.IList<Argument> Arguments { get; }
     public System.Collections.Generic.IEnumerable<Symbol> Children { get; }
     public ICommandHandler Handler { get; set; }
@@ -75,7 +69,7 @@ System.CommandLine
     public CommandLineBuilder UseEnvironmentVariableDirective()
     public CommandLineBuilder UseExceptionHandler(System.Action<System.Exception,System.CommandLine.Invocation.InvocationContext> onException = null, System.Nullable<System.Int32> errorExitCode = null)
     public CommandLineBuilder UseHelp(System.Nullable<System.Int32> maxWidth = null)
-    public CommandLineBuilder UseHelp(System.String[] helpAliases)
+    public CommandLineBuilder UseHelp(System.String name, System.String[] helpAliases)
     public CommandLineBuilder UseHelp(System.Action<System.CommandLine.Help.HelpContext> customize, System.Nullable<System.Int32> maxWidth = null)
     public CommandLineBuilder UseHelpBuilder(System.Func<System.CommandLine.Binding.BindingContext,System.CommandLine.Help.HelpBuilder> getHelpBuilder)
     public CommandLineBuilder UseParseDirective(System.Int32 errorExitCode = 1)
@@ -84,7 +78,7 @@ System.CommandLine
     public CommandLineBuilder UseTokenReplacer(System.CommandLine.Parsing.TryReplaceToken replaceToken)
     public CommandLineBuilder UseTypoCorrections(System.Int32 maxLevenshteinDistance = 3)
     public CommandLineBuilder UseVersionOption()
-    public CommandLineBuilder UseVersionOption(System.String[] aliases)
+    public CommandLineBuilder UseVersionOption(System.String name, System.String[] aliases)
   public class CommandLineConfiguration
     public static CommandLineBuilder CreateBuilder(Command rootCommand)
     .ctor(Command command, System.Boolean enablePosixBundling = True, System.Boolean enableDirectives = True, System.Boolean enableTokenReplacement = True, System.Collections.Generic.IReadOnlyList<System.CommandLine.Invocation.InvocationMiddleware> middlewarePipeline = null, System.Func<System.CommandLine.Binding.BindingContext,System.CommandLine.Help.HelpBuilder> helpBuilderFactory = null, System.CommandLine.Parsing.TryReplaceToken tokenReplacer = null)
@@ -137,32 +131,24 @@ System.CommandLine
     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)
   public interface IConsole : System.CommandLine.IO.IStandardError, System.CommandLine.IO.IStandardIn, System.CommandLine.IO.IStandardOut
-  public abstract class IdentifierSymbol : Symbol
-    public System.Collections.Generic.IReadOnlyCollection<System.String> Aliases { get; }
-    public System.Void AddAlias(System.String alias)
-    public System.Boolean HasAlias(System.String alias)
-  public abstract class Option : IdentifierSymbol, System.CommandLine.Binding.IValueDescriptor
+  public abstract class Option : Symbol, System.CommandLine.Binding.IValueDescriptor
+    public System.Collections.Generic.ICollection<System.String> Aliases { get; }
     public System.Boolean AllowMultipleArgumentsPerToken { get; set; }
     public System.Boolean AppliesToSelfAndChildren { get; set; }
-    public System.String ArgumentHelpName { get; set; }
     public ArgumentArity Arity { get; set; }
     public System.Collections.Generic.List<System.Func<System.CommandLine.Completions.CompletionContext,System.Collections.Generic.IEnumerable<System.CommandLine.Completions.CompletionItem>>> CompletionSources { get; }
+    public System.String HelpName { get; set; }
     public System.Boolean IsRequired { get; set; }
     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
-    .ctor(System.String name, System.String description = null)
-    .ctor(System.String[] aliases, System.String description = null)
-    .ctor(System.String name, Func<System.CommandLine.Parsing.ArgumentResult,T> parseArgument, System.Boolean isDefault = False, System.String description = null)
-    .ctor(System.String[] aliases, Func<System.CommandLine.Parsing.ArgumentResult,T> parseArgument, System.Boolean isDefault = False, System.String description = null)
-    .ctor(System.String name, Func<T> defaultValueFactory, System.String description = null)
-    .ctor(System.String[] aliases, Func<T> defaultValueFactory, System.String description = null)
+    .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; }
     public System.Void AcceptLegalFileNamesOnly()
     public System.Void AcceptLegalFilePathsOnly()
     public System.Void AcceptOnlyFromAmong(System.String[] values)
-    public System.Void SetDefaultValue(T value)
-    public System.Void SetDefaultValueFactory(Func<T> defaultValueFactory)
   public static class OptionValidation
     public static Option<System.IO.FileInfo> AcceptExistingOnly(this Option<System.IO.FileInfo> option)
     public static Option<System.IO.DirectoryInfo> AcceptExistingOnly(this Option<System.IO.DirectoryInfo> option)
@@ -194,7 +180,7 @@ System.CommandLine
   public abstract class Symbol
     public System.String Description { get; set; }
     public System.Boolean IsHidden { get; set; }
-    public System.String Name { get; set; }
+    public System.String Name { get; }
     public System.Collections.Generic.IEnumerable<Symbol> Parents { get; }
     public System.Collections.Generic.IEnumerable<System.CommandLine.Completions.CompletionItem> GetCompletions(System.CommandLine.Completions.CompletionContext context)
     public System.String ToString()
@@ -258,9 +244,9 @@ System.CommandLine.Help
     public static System.String GetArgumentDefaultValue(System.CommandLine.Argument argument)
     public static System.String GetArgumentDescription(System.CommandLine.Argument argument)
     public static System.String GetArgumentUsageLabel(System.CommandLine.Argument argument)
-    public static System.String GetIdentifierSymbolDescription(System.CommandLine.IdentifierSymbol symbol)
-    public static System.String GetIdentifierSymbolUsageLabel(System.CommandLine.IdentifierSymbol symbol, HelpContext context)
+    public static System.String GetCommandUsageLabel(System.CommandLine.Command symbol)
     public static System.Collections.Generic.IEnumerable<System.Action<HelpContext>> GetLayout()
+    public static System.String GetOptionUsageLabel(System.CommandLine.Option symbol)
     public static System.Action<HelpContext> OptionsSection()
     public static System.Action<HelpContext> SubcommandsSection()
     public static System.Action<HelpContext> SynopsisSection()
@@ -350,12 +336,14 @@ System.CommandLine.Parsing
     public System.Collections.Generic.IEnumerable<SymbolResult> Children { get; }
     public System.CommandLine.Command Command { get; }
     public Token Token { get; }
+    public System.String ToString()
   public class OptionResult : SymbolResult
     public System.Boolean IsImplicit { get; }
     public System.CommandLine.Option Option { get; }
     public Token Token { get; }
     public System.Object GetValueOrDefault()
     public T GetValueOrDefault<T>()
+    public System.String ToString()
   public class ParseError
     public System.String Message { get; }
     public SymbolResult SymbolResult { get; }
@@ -374,7 +362,6 @@ System.CommandLine.Parsing
     public OptionResult FindResultFor(System.CommandLine.Option option)
     public T GetValue<T>(Argument<T> argument)
     public T GetValue<T>(Option<T> option)
-    public System.String ToString()
   public class Token, System.IEquatable<Token>
     public static System.Boolean op_Equality(Token left, Token right)
     public static System.Boolean op_Inequality(Token left, Token right)

src/System.CommandLine.ApiCompatibility.Tests/LocalizationTests.cs

@@ -21,7 +21,7 @@ public void ErrorMessages_AreLocalized(string cultureName, string expectedMessag
 
                 Command command = new(CommandName)
                 {
-                    new Argument<string>()
+                    new Argument<string>("arg")
                 };
 
                 ParseResult parseResult = command.Parse(CommandName);

src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_CustomScenarios.cs

@@ -21,7 +21,7 @@ public void SetupOneOptWithNestedCommand()
         {
             _rootCommand = new Command("root_command");
             var nestedCommand = new Command("nested_command");
-            var option = new Option<int>("-opt1", () => 123);
+            var option = new Option<int>("-opt1") { DefaultValueFactory = (_) => 123 };
             nestedCommand.Options.Add(option);
             _rootCommand.Subcommands.Add(nestedCommand);
 

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

@@ -24,8 +24,8 @@ public class Perf_Parser_Simple
 
         private static RootCommand BuildCommand()
         {
-            Option<bool> boolOption = new(new[] { "--bool", "-b" }, "Bool option");
-            Option<string> stringOption = new(new[] { "--string", "-s" }, "String option");
+            Option<bool> boolOption = new("--bool", "-b") { Description = "Bool option" };
+            Option<string> stringOption = new("--string", "-s") { Description = "String option" };
 
             RootCommand command = new()
             {

src/System.CommandLine.DragonFruit.Tests/CommandLineTests.cs

@@ -63,7 +63,7 @@ public async Task It_shows_help_text_based_on_XML_documentation_comments()
                 .Contain("<args>  These are arguments")
                 .And.Contain("Arguments:");
             stdOut.Should()
-                .ContainAll("--name <name>", "Specifies the name option")
+                .ContainAll("--name", "Specifies the name option")
                 .And.Contain("Options:");
             stdOut.Should()
                 .Contain($"Description:{Environment.NewLine}  Normal summary");
@@ -87,7 +87,7 @@ public async Task When_XML_documentation_comment_contains_a_para_tag_then_help_i
                 .Contain("<args>  These are arguments")
                 .And.Contain("Arguments:");
             stdOut.Should()
-                .ContainAll("--name <name>", "Specifies the name option")
+                .ContainAll("--name", "Specifies the name option")
                 .And.Contain("Options:");
             stdOut.Should()
                 .Contain($"Description:{Environment.NewLine}  Help for the test program{Environment.NewLine}  More help for the test program{Environment.NewLine}");
@@ -111,7 +111,7 @@ public async Task When_XML_documentation_comment_contains_a_para_tag_and_some_te
                 .Contain("<args>  These are arguments")
                 .And.Contain("Arguments:");
             stdOut.Should()
-                .ContainAll("--name <name>", "Specifies the name option")
+                .ContainAll("--name", "Specifies the name option")
                 .And.Contain("Options:");
             stdOut.Should()
                 .Contain($"Description:{Environment.NewLine}  Help for the test program{Environment.NewLine}  More help for the test program{Environment.NewLine}");
@@ -132,7 +132,7 @@ public void It_synchronously_shows_help_text_based_on_XML_documentation_comments
             var stdOut = _terminal.Out.ToString();
 
             stdOut.Should()
-                .ContainAll("--name <name>","name [default: Bruce]")
+                .ContainAll("--name","name [default: Bruce]")
                 .And.Contain("Options:");
         }
 

src/System.CommandLine.DragonFruit/CommandLine.cs

@@ -310,6 +310,11 @@ private static bool HasAliasIgnoringPrefix(Option option, string alias)
         {
             ReadOnlySpan<char> rawAlias = alias.AsSpan(GetPrefixLength(alias));
 
+            if (MemoryExtensions.Equals(option.Name.AsSpan(GetPrefixLength(option.Name)), rawAlias, StringComparison.CurrentCulture))
+            {
+                return true;
+            }
+
             foreach (string existingAlias in option.Aliases)
             {
                 if (MemoryExtensions.Equals(existingAlias.AsSpan(GetPrefixLength(existingAlias)), rawAlias, StringComparison.CurrentCulture))