Helpers for Contacts_ResolvedPeer. Fix some examples

EXAMPLES.md

@@ -15,14 +15,17 @@ Remember that these are just simple example codes that you should adjust to your
 ```csharp
 using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
 await client.LoginUserIfNeeded();
-var resolved = await client.Contacts_ResolveUsername("USERNAME");
+var resolved = await client.Contacts_ResolveUsername("username");
-await client.SendMessageAsync(resolved.users[resolved.peer.ID], "Hello!");
+await client.SendMessageAsync(resolved, "Hello!");
 ```
+*Note: This also works if the @username points to a chat, but you must join the chat before posting there.
+You can check `resolved` properties to ensure it's a user or a chat. If the username is invalid/unused, the API call raises an exception.*
 ### Send a message to someone by phone number
 ```csharp
 using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
 await client.LoginUserIfNeeded();
 var contacts = await client.Contacts_ImportContacts(new[] { new InputPhoneContact { phone = "+PHONENUMBER" } });
+if (contacts.imported.Length > 0)
     await client.SendMessageAsync(contacts.users[contacts.imported[0].user_id], "Hello!");
 ```
 *Note: To prevent spam, Telegram may restrict your ability to add new phone numbers.*
@@ -95,7 +98,7 @@ For a simple Chat: (see Terminology in [ReadMe](README.md#Terminology-in-Telegra
 using var client = new WTelegram.Client(Environment.GetEnvironmentVariable);
 await client.LoginUserIfNeeded();
 var chatFull = await client.Messages_GetFullChat(1234567890); // the chat we want
-foreach (var user in chatFull.users)
+foreach (var (id, user) in chatFull.users)
     Console.WriteLine(user);
 ```
 
@@ -108,7 +111,7 @@ var channel = (Channel)chats.chats[1234567890]; // the channel we want
 for (int offset = 0; ;)
 {
     var participants = await client.Channels_GetParticipants(channel, null, offset, 1000, 0);
-    foreach (var user in participants.users)
+    foreach (var (id, user) in participants.users)
         Console.WriteLine(user);
     offset += participants.participants.Length;
     if (offset >= participants.count) break;

src/Helpers.TL.cs

@@ -99,6 +99,55 @@ namespace TL
 		protected override InputUserBase ToInputUser() => new InputUser { user_id = id, access_hash = access_hash };
 	}
 
+	partial class Peer { public abstract long ID { get; } }
+	partial class PeerUser { public override long ID => user_id; public override string ToString() => "user " + user_id; }
+	partial class PeerChat { public override long ID => chat_id; public override string ToString() => "chat " + chat_id; }
+	partial class PeerChannel { public override long ID => channel_id; public override string ToString() => "channel " + channel_id; }
+
+	partial class Contacts_ResolvedPeer
+	{
+		public static implicit operator InputPeer(Contacts_ResolvedPeer resolved) => resolved.UserOrChat.ToInputPeer();
+		public UserBase User => peer is PeerUser pu ? users[pu.user_id] : null;
+		public ChatBase Chat => peer is PeerChat or PeerChannel ? chats[peer.ID] : null;
+		public IPeerInfo UserOrChat => peer switch
+		{
+			PeerUser pu => users[pu.user_id],
+			PeerChat pc => chats[pc.chat_id],
+			PeerChannel pch => chats[pch.channel_id],
+			_ => null
+		};
+	}
+
+	partial class DialogBase
+	{
+		public abstract Peer Peer { get; }
+		public abstract int TopMessage { get; }
+	}
+	partial class Dialog
+	{
+		public override Peer Peer => peer;
+		public override int TopMessage => top_message;
+	}
+	partial class DialogFolder
+	{
+		public override Peer Peer => peer;
+		public override int TopMessage => top_message;
+	}
+
+	partial class Messages_Dialogs
+	{
+		/// <summary>Find the matching User/Chat object for a dialog</summary>
+		/// <param name="dialog">The dialog which peer we want details on</param>
+		/// <returns>a UserBase or ChatBase derived instance</returns>
+		public IPeerInfo GetUserOrChat(DialogBase dialog) => dialog.Peer switch
+		{
+			PeerUser pu => users[pu.user_id],
+			PeerChat pc => chats[pc.chat_id],
+			PeerChannel pch => chats[pch.channel_id],
+			_ => null,
+		};
+	}
+
 	partial class MessageBase
 	{
 		public abstract int ID { get; }
@@ -263,41 +312,6 @@ namespace TL
 		public static implicit operator InputStickerSetID(StickerSet stickerSet) => new() { id = stickerSet.id, access_hash = stickerSet.access_hash };
 	}
 
-	partial class Peer { public abstract long ID { get; }  }
-	partial class PeerUser { public override long ID => user_id; public override string ToString() => "user " + user_id; }
-	partial class PeerChat { public override long ID => chat_id; public override string ToString() => "chat " + chat_id; }
-	partial class PeerChannel { public override long ID => channel_id; public override string ToString() => "channel " + channel_id; }
-
-	partial class DialogBase
-	{
-		public abstract Peer Peer { get; }
-		public abstract int TopMessage { get; }
-	}
-	partial class Dialog
-	{
-		public override Peer Peer => peer;
-		public override int TopMessage => top_message;
-	}
-	partial class DialogFolder
-	{
-		public override Peer Peer => peer;
-		public override int TopMessage => top_message;
-	}
-
-	partial class Messages_Dialogs
-	{
-		/// <summary>Find the matching User/Chat object for a dialog</summary>
-		/// <param name="dialog">The dialog which peer we want details on</param>
-		/// <returns>a UserBase or ChatBase derived instance</returns>
-		public IPeerInfo GetUserOrChat(DialogBase dialog) => dialog.Peer switch
-		{
-			PeerUser pu => users[pu.user_id],
-			PeerChat pc => chats[pc.chat_id],
-			PeerChannel pch => chats[pch.channel_id],
-			_ => null,
-		};
-	}
-
 	partial class JsonObjectValue { public override string ToString() => $"{HttpUtility.JavaScriptStringEncode(key, true)}:{value}"; }
 	partial class JsonNull { public override string ToString() => "null"; }
 	partial class JsonBool { public override string ToString() => value ? "true" : "false"; }