Add non-capturing overloads of Modify methods

src/Discord.Net.Core/Entities/Channels/IGuildChannel.cs

@@ -57,6 +57,20 @@ public interface IGuildChannel : IChannel, IDeletable
         ///     A task that represents the asynchronous modification operation.
         /// </returns>
         Task ModifyAsync(Action<GuildChannelProperties> func, RequestOptions options = null);
+        /// <summary>
+        ///     Modifies this guild channel.
+        /// </summary>
+        /// <remarks>
+        ///     This method modifies the current guild channel with the specified properties. To see an example of this
+        ///     method and what properties are available, please refer to <see cref="GuildChannelProperties"/>.
+        /// </remarks>
+        /// <param name="func">The delegate containing the properties to modify the channel with.</param>
+        /// <param name="state">An object to carry state into the delegate to prevent closures.</param>
+        /// <param name="options">The options to be used when sending the request.</param>
+        /// <returns>
+        ///     A task that represents the asynchronous modification operation.
+        /// </returns>
+        Task ModifyAsync<TState>(Action<GuildChannelProperties, TState> func, TState state, RequestOptions options = null);
 
         /// <summary>
         ///     Gets the permission overwrite for a specific role.

src/Discord.Net.Core/Entities/Channels/ITextChannel.cs

@@ -83,7 +83,18 @@ public interface ITextChannel : IMessageChannel, IMentionable, INestedChannel
         /// </returns>
         /// <seealso cref="TextChannelProperties"/>
         Task ModifyAsync(Action<TextChannelProperties> func, RequestOptions options = null);
-
+        /// <summary>
+        ///     Modifies this text channel.
+        /// </summary>
+        /// <param name="func">The delegate containing the properties to modify the channel with.</param>
+        /// <param name="state">An object to carry state into the delegate to prevent closures.</param>
+        /// <param name="options">The options to be used when sending the request.</param>
+        /// <returns>
+        ///     A task that represents the asynchronous modification operation.
+        /// </returns>
+        /// <seealso cref="TextChannelProperties"/>
+        Task ModifyAsync<TState>(Action<TextChannelProperties, TState> func, TState state, RequestOptions options = null);
+
         /// <summary>
         ///     Creates a webhook in this text channel.
         /// </summary>

src/Discord.Net.Core/Entities/Channels/IVoiceChannel.cs

@@ -35,5 +35,16 @@ public interface IVoiceChannel : INestedChannel, IAudioChannel
         /// </returns>
         /// <seealso cref="VoiceChannelProperties"/>
         Task ModifyAsync(Action<VoiceChannelProperties> func, RequestOptions options = null);
+        /// <summary>
+        ///     Modifies this voice channel.
+        /// </summary>
+        /// <param name="func">The properties to modify the channel with.</param>
+        /// <param name="state">An object to carry state into the delegate to prevent closures.</param>
+        /// <param name="options">The options to be used when sending the request.</param>
+        /// <returns>
+        ///     A task that represents the asynchronous modification operation.
+        /// </returns>
+        /// <seealso cref="VoiceChannelProperties"/>
+        Task ModifyAsync<TState>(Action<VoiceChannelProperties, TState> func, TState state, RequestOptions options = null);
     }
 }

src/Discord.Net.Core/Entities/Guilds/IGuild.cs

@@ -259,6 +259,16 @@ public interface IGuild : IDeletable, ISnowflakeEntity
         /// </returns>
         Task ModifyAsync(Action<GuildProperties> func, RequestOptions options = null);
         /// <summary>
+        ///     Modifies this guild.
+        /// </summary>
+        /// <param name="func">The delegate containing the properties to modify the guild with.</param>
+        /// <param name="state">An object to carry state into the delegate to prevent closures.</param>
+        /// <param name="options">The options to be used when sending the request.</param>
+        /// <returns>
+        ///     A task that represents the asynchronous modification operation.
+        /// </returns>
+        Task ModifyAsync<TState>(Action<GuildProperties, TState> func, TState state, RequestOptions options = null);
+        /// <summary>
         ///     Modifies this guild's embed channel.
         /// </summary>
         /// <param name="func">The delegate containing the properties to modify the guild widget with.</param>
@@ -268,6 +278,16 @@ public interface IGuild : IDeletable, ISnowflakeEntity
         /// </returns>
         Task ModifyEmbedAsync(Action<GuildEmbedProperties> func, RequestOptions options = null);
         /// <summary>
+        ///     Modifies this guild's embed channel.
+        /// </summary>
+        /// <param name="func">The delegate containing the properties to modify the guild widget with.</param>
+        /// <param name="state">An object to carry state into the delegate to prevent closures.</param>
+        /// <param name="options">The options to be used when sending the request.</param>
+        /// <returns>
+        ///     A task that represents the asynchronous modification operation.
+        /// </returns>
+        Task ModifyEmbedAsync<TState>(Action<GuildEmbedProperties, TState> func, TState state, RequestOptions options = null);
+        /// <summary>
         ///     Bulk-modifies the order of channels in this guild.
         /// </summary>
         /// <param name="args">The properties used to modify the channel positions with.</param>

src/Discord.Net.Core/Entities/Messages/IUserMessage.cs

@@ -29,6 +29,26 @@ public interface IUserMessage : IMessage
         /// </returns>
         Task ModifyAsync(Action<MessageProperties> func, RequestOptions options = null);
         /// <summary>
+        ///     Modifies this message.
+        /// </summary>
+        /// <remarks>
+        ///     This method modifies this message with the specified properties. To see an example of this
+        ///     method and what properties are available, please refer to <see cref="MessageProperties"/>.
+        /// </remarks>
+        /// <example>
+        ///     The following example replaces the content of the message with <c>Hello World!</c>.
+        ///     <code language="cs">
+        ///     await msg.ModifyAsync((x, s) =&gt; x.Content = s, "Hello World!");
+        ///     </code>
+        /// </example>
+        /// <param name="func">A delegate containing the properties to modify the message with.</param>
+        /// <param name="state">An object to carry state into the delegate to prevent closures.</param>
+        /// <param name="options">The options to be used when sending the request.</param>
+        /// <returns>
+        ///     A task that represents the asynchronous modification operation.
+        /// </returns>
+        Task ModifyAsync<TState>(Action<MessageProperties, TState> func, TState state, RequestOptions options = null);
+        /// <summary>
         ///     Modifies the suppression of this message.
         /// </summary>
         /// <remarks>

src/Discord.Net.Core/Entities/Roles/IRole.cs

@@ -79,5 +79,19 @@ public interface IRole : ISnowflakeEntity, IDeletable, IMentionable, IComparable
         ///     A task that represents the asynchronous modification operation.
         /// </returns>
         Task ModifyAsync(Action<RoleProperties> func, RequestOptions options = null);
+        /// <summary>
+        ///     Modifies this role.
+        /// </summary>
+        /// <remarks>
+        ///     This method modifies this role with the specified properties. To see an example of this
+        ///     method and what properties are available, please refer to <see cref="RoleProperties"/>.
+        /// </remarks>
+        /// <param name="func">A delegate containing the properties to modify the role with.</param>
+        /// <param name="state">An object to carry state into the delegate to prevent closures.</param>
+        /// <param name="options">The options to be used when sending the request.</param>
+        /// <returns>
+        ///     A task that represents the asynchronous modification operation.
+        /// </returns>
+        Task ModifyAsync<TState>(Action<RoleProperties, TState> func, TState state, RequestOptions options = null);
     }
 }

src/Discord.Net.Core/Entities/Users/IGuildUser.cs

@@ -108,6 +108,20 @@ public interface IGuildUser : IUser, IVoiceState
         ///     A task that represents the asynchronous modification operation.
         /// </returns>
         Task ModifyAsync(Action<GuildUserProperties> func, RequestOptions options = null);
+        /// <summary>
+        ///     Modifies this user's properties in this guild.
+        /// </summary>
+        /// <remarks>
+        ///     This method modifies the current guild user with the specified properties. To see an example of this
+        ///     method and what properties are available, please refer to <see cref="GuildUserProperties"/>.
+        /// </remarks>
+        /// <param name="func">The delegate containing the properties to modify the user with.</param>
+        /// <param name="state">An object to carry state into the delegate to prevent closures.</param>
+        /// <param name="options">The options to be used when sending the request.</param>
+        /// <returns>
+        ///     A task that represents the asynchronous modification operation.
+        /// </returns>
+        Task ModifyAsync<TState>(Action<GuildUserProperties, TState> func, TState state, RequestOptions options = null);
 
         /// <summary>
         ///     Adds the specified role to this user in the guild.

src/Discord.Net.Core/Entities/Users/ISelfUser.cs

@@ -59,5 +59,9 @@ public interface ISelfUser : IUser
         ///     Modifies the user's properties.
         /// </summary>
         Task ModifyAsync(Action<SelfUserProperties> func, RequestOptions options = null);
+        /// <summary>
+        ///     Modifies the user's properties.
+        /// </summary>
+        Task ModifyAsync<TState>(Action<SelfUserProperties, TState> func, TState state, RequestOptions options = null);
     }
 }

src/Discord.Net.Core/Entities/Webhooks/IWebhook.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Threading.Tasks;
 
 namespace Discord
@@ -53,5 +53,9 @@ public interface IWebhook : IDeletable, ISnowflakeEntity
         ///     Modifies this webhook.
         /// </summary>
         Task ModifyAsync(Action<WebhookProperties> func, RequestOptions options = null);
+        /// <summary>
+        ///     Modifies this webhook.
+        /// </summary>
+        Task ModifyAsync<TState>(Action<WebhookProperties, TState> func, TState state, RequestOptions options = null);
     }
 }

src/Discord.Net.Rest/Entities/Channels/ChannelHelper.cs

@@ -18,12 +18,13 @@ public static async Task DeleteAsync(IChannel channel, BaseDiscordClient client,
         {
             await client.ApiClient.DeleteChannelAsync(channel.Id, options).ConfigureAwait(false);
         }
-        public static async Task<Model> ModifyAsync(IGuildChannel channel, BaseDiscordClient client,
-            Action<GuildChannelProperties> func,
+        public static async Task<Model> ModifyAsync<TState>(IGuildChannel channel, BaseDiscordClient client,
+            Action<GuildChannelProperties, TState> func,
+            TState state,
             RequestOptions options)
         {
             var args = new GuildChannelProperties();
-            func(args);
+            func(args, state);
             var apiArgs = new API.Rest.ModifyGuildChannelParams
             {
                 Name = args.Name,
@@ -32,12 +33,13 @@ public static async Task<Model> ModifyAsync(IGuildChannel channel, BaseDiscordCl
             };
             return await client.ApiClient.ModifyGuildChannelAsync(channel.Id, apiArgs, options).ConfigureAwait(false);
         }
-        public static async Task<Model> ModifyAsync(ITextChannel channel, BaseDiscordClient client,
-            Action<TextChannelProperties> func,
+        public static async Task<Model> ModifyAsync<TState>(ITextChannel channel, BaseDiscordClient client,
+            Action<TextChannelProperties, TState> func,
+            TState state,
             RequestOptions options)
         {
             var args = new TextChannelProperties();
-            func(args);
+            func(args, state);
             var apiArgs = new API.Rest.ModifyTextChannelParams
             {
                 Name = args.Name,
@@ -49,12 +51,13 @@ public static async Task<Model> ModifyAsync(ITextChannel channel, BaseDiscordCli
             };
             return await client.ApiClient.ModifyGuildChannelAsync(channel.Id, apiArgs, options).ConfigureAwait(false);
         }
-        public static async Task<Model> ModifyAsync(IVoiceChannel channel, BaseDiscordClient client,
-            Action<VoiceChannelProperties> func,
+        public static async Task<Model> ModifyAsync<TState>(IVoiceChannel channel, BaseDiscordClient client,
+            Action<VoiceChannelProperties, TState> func,
+            TState state,
             RequestOptions options)
         {
             var args = new VoiceChannelProperties();
-            func(args);
+            func(args, state);
             var apiArgs = new API.Rest.ModifyVoiceChannelParams
             {
                 Bitrate = args.Bitrate,

src/Discord.Net.Rest/Entities/Channels/RestGuildChannel.cs

@@ -65,9 +65,12 @@ public override async Task UpdateAsync(RequestOptions options = null)
             Update(model);
         }
         /// <inheritdoc />
-        public async Task ModifyAsync(Action<GuildChannelProperties> func, RequestOptions options = null)
+        public Task ModifyAsync(Action<GuildChannelProperties> func, RequestOptions options = null)
+            => ModifyAsync((props, f) => f(props), func, options);
+        /// <inheritdoc />
+        public async Task ModifyAsync<TState>(Action<GuildChannelProperties, TState> func, TState state, RequestOptions options = null)
         {
-            var model = await ChannelHelper.ModifyAsync(this, Discord, func, options).ConfigureAwait(false);
+            var model = await ChannelHelper.ModifyAsync(this, Discord, func, state, options).ConfigureAwait(false);
             Update(model);
         }
         /// <inheritdoc />

src/Discord.Net.Rest/Entities/Channels/RestTextChannel.cs

@@ -47,9 +47,12 @@ internal override void Update(Model model)
         }
 
         /// <inheritdoc />
-        public async Task ModifyAsync(Action<TextChannelProperties> func, RequestOptions options = null)
+        public Task ModifyAsync(Action<TextChannelProperties> func, RequestOptions options = null)
+            => ModifyAsync((props, f) => f(props), func, options);
+        /// <inheritdoc />
+        public async Task ModifyAsync<TState>(Action<TextChannelProperties, TState> func, TState state, RequestOptions options = null)
         {
-            var model = await ChannelHelper.ModifyAsync(this, Discord, func, options).ConfigureAwait(false);
+            var model = await ChannelHelper.ModifyAsync(this, Discord, func, state, options).ConfigureAwait(false);
             Update(model);
         }
 

src/Discord.Net.Rest/Entities/Channels/RestVoiceChannel.cs

@@ -41,9 +41,12 @@ internal override void Update(Model model)
         }
 
         /// <inheritdoc />
-        public async Task ModifyAsync(Action<VoiceChannelProperties> func, RequestOptions options = null)
+        public Task ModifyAsync(Action<VoiceChannelProperties> func, RequestOptions options = null)
+            => ModifyAsync((props, f) => f(props), func, options);
+        /// <inheritdoc />
+        public async Task ModifyAsync<TState>(Action<VoiceChannelProperties, TState> func, TState state, RequestOptions options = null)
         {
-            var model = await ChannelHelper.ModifyAsync(this, Discord, func, options).ConfigureAwait(false);
+            var model = await ChannelHelper.ModifyAsync(this, Discord, func, state, options).ConfigureAwait(false);
             Update(model);
         }
 

src/Discord.Net.Rest/Entities/Guilds/GuildHelper.cs

@@ -15,13 +15,13 @@ internal static class GuildHelper
     {
         //General
         /// <exception cref="ArgumentNullException"><paramref name="func"/> is <c>null</c>.</exception>
-        public static async Task<Model> ModifyAsync(IGuild guild, BaseDiscordClient client,
-            Action<GuildProperties> func, RequestOptions options)
+        public static async Task<Model> ModifyAsync<TState>(IGuild guild, BaseDiscordClient client,
+            Action<GuildProperties, TState> func, TState state, RequestOptions options)
         {
             if (func == null) throw new ArgumentNullException(nameof(func));
 
             var args = new GuildProperties();
-            func(args);
+            func(args, state);
 
             var apiArgs = new API.Rest.ModifyGuildParams
             {
@@ -71,13 +71,13 @@ public static async Task<Model> ModifyAsync(IGuild guild, BaseDiscordClient clie
             return await client.ApiClient.ModifyGuildAsync(guild.Id, apiArgs, options).ConfigureAwait(false);
         }
         /// <exception cref="ArgumentNullException"><paramref name="func"/> is <c>null</c>.</exception>
-        public static async Task<EmbedModel> ModifyEmbedAsync(IGuild guild, BaseDiscordClient client,
-            Action<GuildEmbedProperties> func, RequestOptions options)
+        public static async Task<EmbedModel> ModifyEmbedAsync<TState>(IGuild guild, BaseDiscordClient client,
+            Action<GuildEmbedProperties, TState> func, TState state, RequestOptions options)
         {
             if (func == null) throw new ArgumentNullException(nameof(func));
 
             var args = new GuildEmbedProperties();
-            func(args);
+            func(args, state);
             var apiArgs = new API.Rest.ModifyGuildEmbedParams
             {
                 Enabled = args.Enabled

src/Discord.Net.Rest/Entities/Guilds/RestGuild.cs

@@ -166,17 +166,25 @@ public Task DeleteAsync(RequestOptions options = null)
 
         /// <inheritdoc />
         /// <exception cref="ArgumentNullException"><paramref name="func"/> is <c>null</c>.</exception>
-        public async Task ModifyAsync(Action<GuildProperties> func, RequestOptions options = null)
+        public Task ModifyAsync(Action<GuildProperties> func, RequestOptions options = null)
+            => ModifyAsync((props, f) => f(props), func, options);
+        /// <inheritdoc />
+        /// <exception cref="ArgumentNullException"><paramref name="func"/> is <c>null</c>.</exception>
+        public async Task ModifyAsync<TState>(Action<GuildProperties, TState> func, TState state, RequestOptions options = null)
         {
-            var model = await GuildHelper.ModifyAsync(this, Discord, func, options).ConfigureAwait(false);
+            var model = await GuildHelper.ModifyAsync(this, Discord, func, state, options).ConfigureAwait(false);
             Update(model);
         }
 
         /// <inheritdoc />
         /// <exception cref="ArgumentNullException"><paramref name="func"/> is <c>null</c>.</exception>
-        public async Task ModifyEmbedAsync(Action<GuildEmbedProperties> func, RequestOptions options = null)
+        public Task ModifyEmbedAsync(Action<GuildEmbedProperties> func, RequestOptions options = null)
+            => ModifyEmbedAsync((props, f) => f(props), func, options);
+        /// <inheritdoc />
+        /// <exception cref="ArgumentNullException"><paramref name="func"/> is <c>null</c>.</exception>
+        public async Task ModifyEmbedAsync<TState>(Action<GuildEmbedProperties, TState> func, TState state, RequestOptions options = null)
         {
-            var model = await GuildHelper.ModifyEmbedAsync(this, Discord, func, options).ConfigureAwait(false);
+            var model = await GuildHelper.ModifyEmbedAsync(this, Discord, func, state, options).ConfigureAwait(false);
             Update(model);
         }
 

src/Discord.Net.Rest/Entities/Messages/MessageHelper.cs

@@ -13,14 +13,16 @@ internal static class MessageHelper
     {
         /// <exception cref="InvalidOperationException">Only the author of a message may modify the message.</exception>
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
-        public static async Task<Model> ModifyAsync(IMessage msg, BaseDiscordClient client, Action<MessageProperties> func,
+        public static async Task<Model> ModifyAsync<TState>(IMessage msg, BaseDiscordClient client,
+            Action<MessageProperties, TState> func,
+            TState state,
             RequestOptions options)
         {
             if (msg.Author.Id != client.CurrentUser.Id)
                 throw new InvalidOperationException("Only the author of a message may modify the message.");
 
             var args = new MessageProperties();
-            func(args);
+            func(args, state);
 
             var apiArgs = new API.Rest.ModifyMessageParams
             {