Rename ICommandLineValidatable.Validate to ICommandLineProcessed.Process and update documentation.

Author: rstarkov

Src/CommandLineParser.cs

@@ -500,8 +500,8 @@ private static object parseCommandLine(string[] args, Type type, int i, Func<Con
 
         try
         {
-            if (ret is ICommandLineValidatable v)
-                v.Validate();
+            if (ret is ICommandLineProcessed v)
+                v.Process();
         }
         catch (CommandLineValidationException exc) when (exc.GenerateHelpFunc == null)
         {

Src/ICommandLineProcessed.cs

@@ -0,0 +1,20 @@
+namespace RT.CommandLine;
+
+/// <summary>
+///     Contains methods to post-process a class representing command-line options as populated by <see
+///     cref="CommandLineParser"/>.</summary>
+/// <remarks>
+///     If an input doesn’t parse correctly, throw <see cref="CommandLineValidationException"/> with a helpful, descriptive
+///     message that is displayed to the user.</remarks>
+public interface ICommandLineProcessed
+{
+    /// <summary>
+    ///     When implemented in a class, performs application-specific post-processing of the options class.</summary>
+    /// <remarks>
+    ///     When <see cref="CommandLineParser"/> invokes this method, all parsed commands and options have already been
+    ///     populated. This method can thus alter the class in application-specific ways, perform further parsing, or further
+    ///     validate the options for constraints such as mutual exclusivity. To report a validation error, this method should
+    ///     throw a <see cref="CommandLineValidationException"/> with a helpful, descriptive message that is displayed to the
+    ///     user.</remarks>
+    void Process();
+}

Src/ICommandLineValidatable.cs

@@ -4,7 +4,7 @@ namespace RT.CommandLine.Tests;
 
 #pragma warning disable CS0649 // Field is never assigned to and will always have its default value
 
-class Test1Cmd : ICommandLineValidatable
+class Test1Cmd : ICommandLineProcessed
 {
     [IsPositional, IsMandatory]
     public string Base;
@@ -14,17 +14,17 @@ class Test1Cmd : ICommandLineValidatable
 
     public static int ValidateCalled = 0;
 
-    public void Validate()
+    public void Process()
     {
         ValidateCalled++;
     }
 }
 
 [CommandGroup]
-abstract class Test1SubcommandBase : ICommandLineValidatable
+abstract class Test1SubcommandBase : ICommandLineProcessed
 {
     public static int ValidateCalled = 0;
-    public abstract void Validate();
+    public abstract void Process();
 }
 
 [CommandName("sub1")]
@@ -33,7 +33,7 @@ sealed class Test1Subcommand1 : Test1SubcommandBase
     [IsPositional, IsMandatory]
     public string ItemName;
 
-    public override void Validate()
+    public override void Process()
     {
         ValidateCalled++;
     }
@@ -42,5 +42,5 @@ public override void Validate()
 [CommandName("sub2")]
 sealed class Test1Subcommand2 : Test1SubcommandBase
 {
-    public override void Validate() { }
+    public override void Process() { }
 }