Perf improvements part 5.1 (#1601)

Author: adamsitnik

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

@@ -50,12 +50,14 @@
   public class Command : IdentifierSymbol, System.Collections.Generic.IEnumerable<Symbol>, System.Collections.IEnumerable, System.CommandLine.Completions.ICompletionSource
     .ctor(System.String name, System.String description = null)
     public System.Collections.Generic.IReadOnlyList<Argument> Arguments { get; }
-    public System.CommandLine.Collections.SymbolSet Children { get; }
+    public System.Collections.Generic.IEnumerable<Symbol> Children { get; }
     public System.CommandLine.Invocation.ICommandHandler Handler { get; set; }
     public System.Collections.Generic.IReadOnlyList<Option> Options { get; }
+    public System.Collections.Generic.IReadOnlyList<Command> Subcommands { get; }
     public System.Boolean TreatUnmatchedTokensAsErrors { get; set; }
-    public System.Void Add(Symbol symbol)
+    public System.Void Add(Option option)
     public System.Void Add(Argument argument)
+    public System.Void Add(Command command)
     public System.Void AddArgument(Argument argument)
     public System.Void AddCommand(Command command)
     public System.Void AddGlobalOption(Option option)
@@ -77,7 +79,6 @@
     public System.Boolean EnablePosixBundling { get; }
     public LocalizationResources LocalizationResources { get; }
     public Command RootCommand { get; }
-    public System.CommandLine.Collections.SymbolSet Symbols { get; }
     public System.Void ThrowIfInvalid()
   public class CommandLineConfigurationException : System.Exception, System.Runtime.Serialization.ISerializable
     .ctor(System.String message)
@@ -283,12 +284,6 @@ System.CommandLine.Builder
     public static CommandLineBuilder UseTypoCorrections(this CommandLineBuilder builder, System.Int32 maxLevenshteinDistance = 3)
     public static CommandLineBuilder UseVersionOption(this CommandLineBuilder builder)
     public static CommandLineBuilder UseVersionOption(this CommandLineBuilder builder, System.String[] aliases)
-System.CommandLine.Collections
-  public class SymbolSet, System.Collections.Generic.IEnumerable<System.CommandLine.Symbol>, System.Collections.Generic.IReadOnlyCollection<System.CommandLine.Symbol>, System.Collections.Generic.IReadOnlyList<System.CommandLine.Symbol>, System.Collections.IEnumerable
-    .ctor()
-    public System.Int32 Count { get; }
-    public System.CommandLine.Symbol Item { get; }
-    public System.Collections.Generic.IEnumerator<System.CommandLine.Symbol> GetEnumerator()
 System.CommandLine.Completions
   public abstract class CompletionContext
     public System.CommandLine.Parsing.ParseResult ParseResult { get; }

src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_NestedCommands.cs

@@ -56,9 +56,9 @@ public void SetupRootCommand()
 
             // Choose only one path from the commands tree for the test arguments string
             Command currentCmd = rootCommand;
-            while (currentCmd is not null && currentCmd.Children.Count > 0)
+            while (currentCmd is not null && currentCmd.Subcommands.Count > 0)
             {
-                currentCmd = currentCmd.Children[0] as Command;
+                currentCmd = currentCmd.Subcommands[0];
                 _testSymbolsAsString = string.Join(" ", _testSymbolsAsString, currentCmd.Name);
             }
 

src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Options_Bare.cs

@@ -15,7 +15,7 @@ namespace System.CommandLine.Benchmarks.CommandLine
     [BenchmarkCategory(Categories.CommandLine)]
     public class Perf_Parser_Options_Bare
     {
-        private IEnumerable<Symbol> _testSymbols;
+        private IEnumerable<Option> _testSymbols;
         private string _testSymbolsAsString;
         private Parser _testParser;
 

src/System.CommandLine.Benchmarks/Helpers/Utils.cs

@@ -44,7 +44,7 @@ internal static string CreateTestAssemblyInTempFileFromString(string sourceCode,
             return pathToAssemblyFile;
         }
 
-        public static Parser CreateParser(this IEnumerable<Symbol> symbols)
+        public static Parser CreateParser(this IEnumerable<Option> symbols)
         {
             var rootCommand = new RootCommand();
 

src/System.CommandLine.Tests/SymbolSetExtensions.cs

@@ -1,17 +1,17 @@
 // Copyright (c) .NET Foundation and contributors. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
-using System.CommandLine.Collections;
+using System.Collections.Generic;
 using System.Linq;
 
 namespace System.CommandLine.Tests
 {
     internal static class SymbolSetExtensions
     {
-        internal static Symbol GetByAlias(this SymbolSet symbolSet, string alias)
+        internal static Symbol GetByAlias(this IEnumerable<Symbol> symbolSet, string alias)
             => symbolSet.SingleOrDefault(symbol => symbol.Name.Equals(alias) || symbol is IdentifierSymbol id && id.HasAlias(alias));
 
-        internal static bool ContainsAlias(this SymbolSet symbolSet, string alias)
+        internal static bool ContainsAlias(this IEnumerable<Symbol> symbolSet, string alias)
             => symbolSet.OfType<IdentifierSymbol>().Any(symbol => symbol.HasAlias(alias));
     }
 }