remove IDirectiveCollection

Author: jonsequitur

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

@@ -92,6 +92,11 @@
   public static class ConsoleExtensions
     public static System.Void Write(this IConsole console, System.String value)
     public static System.Void WriteLine(this IConsole console, System.String value)
+  public class DirectiveCollection, System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<System.String,System.Collections.Generic.IEnumerable<System.String>>>, System.Collections.IEnumerable
+    .ctor()
+    public System.Boolean Contains(System.String name)
+    public System.Collections.Generic.IEnumerator<System.Collections.Generic.KeyValuePair<System.String,System.Collections.Generic.IEnumerable<System.String>>> GetEnumerator()
+    public System.Boolean TryGetValues(System.String name, ref System.Collections.Generic.IReadOnlyList<System.String> values)
   public static class Handler
     public static System.Void SetHandler(this Command command, System.Action handle)
     public static System.Void SetHandler(this Command command, System.Func<System.Threading.Tasks.Task> handle)
@@ -133,9 +138,6 @@
     public System.String Name { get; set; }
     public System.Void AddAlias(System.String alias)
     public System.Boolean HasAlias(System.String alias)
-  public interface IDirectiveCollection : System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<System.String,System.Collections.Generic.IEnumerable<System.String>>>, System.Collections.IEnumerable
-    public System.Boolean Contains(System.String name)
-    public System.Boolean TryGetValues(System.String name, ref System.Collections.Generic.IReadOnlyList<System.String> values)
   public class LocalizationResources
     public static LocalizationResources Instance { get; }
     public System.String ArgumentConversionCannotParse(System.String value, System.Type expectedType)
@@ -455,7 +457,7 @@ System.CommandLine.Parsing
     public ParseResult Parse(System.Collections.Generic.IReadOnlyList<System.String> arguments, System.String rawInput = null)
   public class ParseResult
     public CommandResult CommandResult { get; }
-    public System.CommandLine.IDirectiveCollection Directives { get; }
+    public System.CommandLine.DirectiveCollection Directives { get; }
     public System.Collections.Generic.IReadOnlyList<ParseError> Errors { get; }
     public Parser Parser { get; }
     public CommandResult RootCommandResult { get; }

src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_ParseResult.cs

@@ -44,7 +44,7 @@ public IEnumerable<object> GenerateTestParseResults()
 
         [Benchmark]
         [ArgumentsSource(nameof(GenerateTestInputs))]
-        public IDirectiveCollection ParseResult_Directives(string input)
+        public DirectiveCollection ParseResult_Directives(string input)
             => _testParser.Parse(input).Directives;
 
         [Benchmark]

src/System.CommandLine/Builder/CommandLineBuilder.cs

@@ -33,7 +33,7 @@ public CommandLineBuilder(Command? rootCommand = null)
         /// <summary>
         /// Determines whether the parser recognizes command line directives.
         /// </summary>
-        /// <seealso cref="IDirectiveCollection"/>
+        /// <seealso cref="DirectiveCollection"/>
         public bool EnableDirectives { get; set; } = true;
 
         /// <summary>

src/System.CommandLine/Builder/CommandLineBuilderExtensions.cs

@@ -102,7 +102,7 @@ public static CommandLineBuilder CancelOnProcessTermination(this CommandLineBuil
         /// <param name="builder">A command line builder.</param>
         /// <param name="value">If set to <see langword="true"/>, then directives are enabled. Otherwise, they are parsed like any other token.</param>
         /// <returns>The same instance of <see cref="CommandLineBuilder"/>.</returns>
-        /// <seealso cref="IDirectiveCollection"/>
+        /// <seealso cref="DirectiveCollection"/>
         public static CommandLineBuilder EnableDirectives(
             this CommandLineBuilder builder,
             bool value = true)
@@ -279,11 +279,11 @@ public static CommandLineBuilder UseEnvironmentVariableDirective(
         {
             builder.AddMiddleware((context, next) =>
             {
-                if (context.ParseResult.Directives.TryGetValues("env", out var directives))
+                if (context.ParseResult.Directives.TryGetValues("env", out var keyValuePairs))
                 {
-                    for (var i = 0; i < directives.Count; i++)
+                    for (var i = 0; i < keyValuePairs.Count; i++)
                     {
-                        var envDirective = directives[i];
+                        var envDirective = keyValuePairs[i];
                         var components = envDirective.Split(new[] { '=' }, count: 2);
                         var variable = components.Length > 0 ? components[0].Trim() : string.Empty;
                         if (string.IsNullOrEmpty(variable) || components.Length < 2)

src/System.CommandLine/DirectiveCollection.cs

@@ -8,12 +8,21 @@
 
 namespace System.CommandLine
 {
-    internal class DirectiveCollection : IDirectiveCollection
+    /// <summary>
+    /// A collection of directives parsed from a command line.
+    /// </summary>
+    /// <remarks>A directive is specified on the command line using square brackets, containing no spaces and preceding other tokens unless they are also directives. In the following example, two directives are present, <c>directive-one</c> and <c>directive-two</c>:
+    /// <code>    > myapp [directive-one] [directive-two:value] arg1 arg2</code>
+    /// The second has a value specified as well, <c>value</c>. Directive values can be read by calling using <see cref="TryGetValues"/>.
+    /// </remarks>
+    public class DirectiveCollection  : IEnumerable<KeyValuePair<string, IEnumerable<string>>>
     {
-        private readonly Dictionary<string, List<string>> _directives = new();
+        private Dictionary<string, List<string>>? _directives;
 
-        public void Add(string name, string? value)
+        internal void Add(string name, string? value)
         {
+            _directives ??= new();
+
             if (!_directives.TryGetValue(name, out var values))
             {
                 values = new List<string>();
@@ -27,14 +36,26 @@ public void Add(string name, string? value)
             }
         }
 
+        /// <summary>
+        /// Gets a value determining whether a directive with the specified name was parsed.
+        /// </summary>
+        /// <param name="name">The name of the directive.</param>
+        /// <returns><see langword="true"/> if a directive with the specified name was parsed; otherwise, <see langword="false"/>.</returns>
         public bool Contains(string name)
         {
-            return _directives.ContainsKey(name);
+            return _directives is not null && _directives.ContainsKey(name);
         }
 
-        public bool TryGetValues(string name,  [NotNullWhen(true)] out IReadOnlyList<string>? values)
+        /// <summary>
+        /// Gets the values specified for a given directive. A return value indicates whether the specified directive name was present.
+        /// </summary>
+        /// <param name="name">The name of the directive.</param>
+        /// <param name="values">The values provided for the specified directive.</param>
+        /// <returns><see langword="true"/> if a directive with the specified name was parsed; otherwise, <see langword="false"/>.</returns>
+        public bool TryGetValues(string name, [NotNullWhen(true)] out IReadOnlyList<string>? values)
         {
-            if (_directives.TryGetValue(name, out var v))
+            if (_directives is not null &&
+                _directives.TryGetValue(name, out var v))
             {
                 values = v;
                 return true;
@@ -46,10 +67,18 @@ public bool TryGetValues(string name,  [NotNullWhen(true)] out IReadOnlyList<str
             }
         }
 
-        public IEnumerator<KeyValuePair<string, IEnumerable<string>>> GetEnumerator() =>
-            _directives
-                .Select(pair => new KeyValuePair<string, IEnumerable<string>>(pair.Key, pair.Value))
-                .GetEnumerator();
+        /// <inheritdoc />
+        public IEnumerator<KeyValuePair<string, IEnumerable<string>>> GetEnumerator()
+        {
+            if (_directives is null)
+            {
+                return Enumerable.Empty<KeyValuePair<string, IEnumerable<string>>>().GetEnumerator();
+            }
+            
+            return _directives
+                   .Select(pair => new KeyValuePair<string, IEnumerable<string>>(pair.Key, pair.Value))
+                   .GetEnumerator();
+        }
 
         IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
     }

src/System.CommandLine/IDirectiveCollection.cs

@@ -24,7 +24,7 @@ internal ParseResult(
             Parser parser,
             RootCommandResult rootCommandResult,
             CommandResult commandResult,
-            IDirectiveCollection directives,
+            DirectiveCollection directives,
             TokenizeResult tokenizeResult,
             IReadOnlyList<Token>? unparsedTokens,
             IReadOnlyList<Token>? unmatchedTokens,
@@ -102,7 +102,7 @@ internal ParseResult(
         /// Gets the directives found while parsing command line input.
         /// </summary>
         /// <remarks>If <see cref="CommandLineConfiguration.EnableDirectives"/> is set to <see langword="false"/>, then this collection will be empty.</remarks>
-        public IDirectiveCollection Directives { get; }
+        public DirectiveCollection Directives { get; }
 
         /// <summary>
         /// Gets the tokens identified while parsing command line input.

src/System.CommandLine/Parsing/ParseResult.cs

@@ -41,7 +41,7 @@ public enum TokenType
         /// <summary>
         /// A directive token.
         /// </summary>
-        /// <see cref="IDirectiveCollection"/>
+        /// <see cref="DirectiveCollection"/>
         Directive
     }
 }