Improved the definitions and equipped them with documentation comments

Author: ajgorhoe

src/IGLib.Core/Console/Validation/DefaultFormatProvider/DefaultFormatProvider.cs

@@ -4,23 +4,40 @@
 using System.Linq;
 using System.Text;
 
-namespace IGLib
-{
+namespace IGLib;
 
-    public class DefaultFormatProviderSelector
-    {
 
-        /// <summary>Returns the global <see cref="IDefaultFormatProviderSelector"/> that is used to provide
-        /// the <see cref="IFormatProvider"/> when one is not specified, and also the the
-        /// <see cref="IDefaultFormatProviderSelector"/> is not specified.</summary>
-        public static IDefaultFormatProviderSelector Global { get; private set; } = 
+public class DefaultFormatProviderSelector
+{
 
-        public static IFormatProvider GetFormatProvider(IFormatProvider? specifiedProvider,
-            IDefaultFormatProviderSelector? selector)
-        {
-            return (specifiedProvider ?? (selector?? Global).DefaultFormatProvider);
-        }
+    /// <summary>Returns the global <see cref="IDefaultFormatProviderSelector"/> that is used to provide
+    /// the <see cref="IFormatProvider"/> when one is not specified, and also the the
+    /// <see cref="IDefaultFormatProviderSelector"/> is not specified.</summary>
+    public static IDefaultFormatProviderSelector Global { get; private set; }
+        = new DefaultFormatProviderSelectorInvariantCulture();
 
+    /// <summary>Returns the appropriate <see cref="IFormatProvider"/> according to the specified (suggested)
+    /// <paramref name="specifiedFormatProvider"/> (that can be null) and the specified <paramref name="defaultSelector"/>,
+    /// which provides the default <see cref="IFormatProvider"/> when the <paramref name="specifiedFormatProvider"/>
+    /// is null If both parameters are null then the default <see cref="IFormatProvider"/> is provided by the
+    /// <see cref="DefaultFormatProviderSelector.Global"/> property.</summary>
+    /// <param name="specifiedFormatProvider">The specified <see cref="IFormatProvider"/>. If not null then this
+    /// object is returned immediately, otherwise the <paramref name="defaultSelector"/> parameter is used to 
+    /// provide the object that is returned.</param>
+    /// <param name="defaultSelector">Provides the default <see cref="IFormatProvider"/> (via the 
+    /// <see cref="IDefaultFormatProviderSelector.DefaultFormatProvider"/> property) in case that the <paramref name="specifiedFormatProvider"/>
+    /// is null. In that case, if this parameter is also null, the <see cref="DefaultFormatProviderSelector.Global"/> provides the
+    /// default object to be returned.</param>
+    /// <returns>The <see cref="IFormatProvider"/> returned according to method parameters:
+    /// <para>* If <paramref name="specifiedFormatProvider"/> is not null, this object is returned.</para>
+    /// <para>* Otherwise, if <paramref name="defaultSelector"/> is not null then the object obtained by its 
+    /// <see cref="IDefaultFormatProviderSelector.DefaultFormatProvider"/> property is returned.</para>
+    /// <para>Otherwise, the format provider obtained by the <see cref="DefaultFormatProviderSelector.Global"/>'s 
+    /// <see cref="IDefaultFormatProviderSelector.DefaultFormatProvider"/> property is returned.</para></returns>
+    public static IFormatProvider GetFormatProvider(IFormatProvider? specifiedFormatProvider,
+        IDefaultFormatProviderSelector? defaultSelector)
+    {
+        return (specifiedFormatProvider ?? (defaultSelector ?? Global).DefaultFormatProvider);
     }
 
 }