Update TypeReaders with C#7 features and IServiceProvider

src/Discord.Net.Commands/CommandMatch.cs

@@ -18,8 +18,8 @@ namespace Discord.Commands
 
         public Task<PreconditionResult> CheckPreconditionsAsync(ICommandContext context, IServiceProvider services = null)
             => Command.CheckPreconditionsAsync(context, services);
-        public Task<ParseResult> ParseAsync(ICommandContext context, SearchResult searchResult, PreconditionResult preconditionResult = null)
-            => Command.ParseAsync(context, Alias.Length, searchResult, preconditionResult);
+        public Task<ParseResult> ParseAsync(ICommandContext context, SearchResult searchResult, PreconditionResult preconditionResult = null, IServiceProvider services = null)
+            => Command.ParseAsync(context, Alias.Length, searchResult, preconditionResult, services);
         public Task<ExecuteResult> ExecuteAsync(ICommandContext context, IEnumerable<object> argList, IEnumerable<object> paramList, IServiceProvider services)
             => Command.ExecuteAsync(context, argList, paramList, services);
         public Task<ExecuteResult> ExecuteAsync(ICommandContext context, ParseResult parseResult, IServiceProvider services)

src/Discord.Net.Commands/CommandParser.cs

@@ -1,4 +1,5 @@
-using System.Collections.Immutable;
+using System;
+using System.Collections.Immutable;
 using System.Text;
 using System.Threading.Tasks;
 
@@ -13,7 +14,7 @@ namespace Discord.Commands
             QuotedParameter
         }
         
-        public static async Task<ParseResult> ParseArgs(CommandInfo command, ICommandContext context, string input, int startPos)
+        public static async Task<ParseResult> ParseArgs(CommandInfo command, ICommandContext context, IServiceProvider services, string input, int startPos)
         {
             ParameterInfo curParam = null;
             StringBuilder argBuilder = new StringBuilder(input.Length);
@@ -110,7 +111,7 @@ namespace Discord.Commands
                     if (curParam == null)
                         return ParseResult.FromError(CommandError.BadArgCount, "The input text has too many parameters.");
 
-                    var typeReaderResult = await curParam.Parse(context, argString).ConfigureAwait(false);
+                    var typeReaderResult = await curParam.Parse(context, argString, services).ConfigureAwait(false);
                     if (!typeReaderResult.IsSuccess && typeReaderResult.Error != CommandError.MultipleMatches)
                         return ParseResult.FromError(typeReaderResult);
 
@@ -133,7 +134,7 @@ namespace Discord.Commands
 
             if (curParam != null && curParam.IsRemainder)
             {
-                var typeReaderResult = await curParam.Parse(context, argBuilder.ToString()).ConfigureAwait(false);
+                var typeReaderResult = await curParam.Parse(context, argBuilder.ToString(), services).ConfigureAwait(false);
                 if (!typeReaderResult.IsSuccess)
                     return ParseResult.FromError(typeReaderResult);
                 argList.Add(typeReaderResult);

src/Discord.Net.Commands/CommandService.cs

@@ -267,7 +267,7 @@ namespace Discord.Commands
                         continue;
                 }
 
-                var parseResult = await commands[i].ParseAsync(context, searchResult, preconditionResult).ConfigureAwait(false);
+                var parseResult = await commands[i].ParseAsync(context, searchResult, preconditionResult, services).ConfigureAwait(false);
                 if (!parseResult.IsSuccess)
                 {
                     if (parseResult.Error == CommandError.MultipleMatches)

src/Discord.Net.Commands/Info/CommandInfo.cs

@@ -105,15 +105,17 @@ namespace Discord.Commands
             return PreconditionResult.FromSuccess();
         }
         
-        public async Task<ParseResult> ParseAsync(ICommandContext context, int startIndex, SearchResult searchResult, PreconditionResult preconditionResult = null)
+        public async Task<ParseResult> ParseAsync(ICommandContext context, int startIndex, SearchResult searchResult, PreconditionResult preconditionResult = null, IServiceProvider services = null)
         {
+            services = services ?? EmptyServiceProvider.Instance;
+
             if (!searchResult.IsSuccess)
                 return ParseResult.FromError(searchResult);
             if (preconditionResult != null && !preconditionResult.IsSuccess)
                 return ParseResult.FromError(preconditionResult);
             
             string input = searchResult.Text.Substring(startIndex);
-            return await CommandParser.ParseArgs(this, context, input, 0).ConfigureAwait(false);
+            return await CommandParser.ParseArgs(this, context, services, input, 0).ConfigureAwait(false);
         }
 
         public Task<ExecuteResult> ExecuteAsync(ICommandContext context, ParseResult parseResult, IServiceProvider services)

src/Discord.Net.Commands/Info/ParameterInfo.cs

@@ -54,9 +54,10 @@ namespace Discord.Commands
             return PreconditionResult.FromSuccess();
         }
 
-        public async Task<TypeReaderResult> Parse(ICommandContext context, string input)
+        public async Task<TypeReaderResult> Parse(ICommandContext context, string input, IServiceProvider services = null)
         {
-            return await _reader.Read(context, input).ConfigureAwait(false);
+            services = services ?? EmptyServiceProvider.Instance;
+            return await _reader.Read(context, input, services).ConfigureAwait(false);
         }
 
         public override string ToString() => Name;

src/Discord.Net.Commands/Readers/ChannelTypeReader.cs

@@ -9,7 +9,7 @@ namespace Discord.Commands
     internal class ChannelTypeReader<T> : TypeReader
         where T : class, IChannel
     {
-        public override async Task<TypeReaderResult> Read(ICommandContext context, string input)
+        public override async Task<TypeReaderResult> Read(ICommandContext context, string input, IServiceProvider services)
         {
             if (context.Guild != null)
             {

src/Discord.Net.Commands/Readers/EnumTypeReader.cs

@@ -44,12 +44,11 @@ namespace Discord.Commands
             _enumsByValue = byValueBuilder.ToImmutable();
         }
 
-        public override Task<TypeReaderResult> Read(ICommandContext context, string input)
+        public override Task<TypeReaderResult> Read(ICommandContext context, string input, IServiceProvider services)
         {
-            T baseValue;
             object enumValue;
 
-            if (_tryParse(input, out baseValue))
+            if (_tryParse(input, out T baseValue))
             {
                 if (_enumsByValue.TryGetValue(baseValue, out enumValue))
                     return Task.FromResult(TypeReaderResult.FromSuccess(enumValue));

src/Discord.Net.Commands/Readers/MessageTypeReader.cs

@@ -1,4 +1,5 @@
-using System.Globalization;
+using System;
+using System.Globalization;
 using System.Threading.Tasks;
 
 namespace Discord.Commands
@@ -6,15 +7,14 @@ namespace Discord.Commands
     internal class MessageTypeReader<T> : TypeReader
         where T : class, IMessage
     {
-        public override async Task<TypeReaderResult> Read(ICommandContext context, string input)
+        public override async Task<TypeReaderResult> Read(ICommandContext context, string input, IServiceProvider services)
         {
             ulong id;
 
             //By Id (1.0)
             if (ulong.TryParse(input, NumberStyles.None, CultureInfo.InvariantCulture, out id))
             {
-                var msg = await context.Channel.GetMessageAsync(id, CacheMode.CacheOnly).ConfigureAwait(false) as T;
-                if (msg != null)
+                if (await context.Channel.GetMessageAsync(id, CacheMode.CacheOnly).ConfigureAwait(false) is T msg)
                     return TypeReaderResult.FromSuccess(msg);
             }
 

src/Discord.Net.Commands/Readers/PrimitiveTypeReader.cs

@@ -21,10 +21,9 @@ namespace Discord.Commands
             _tryParse = PrimitiveParsers.Get<T>();
         }
 
-        public override Task<TypeReaderResult> Read(ICommandContext context, string input)
+        public override Task<TypeReaderResult> Read(ICommandContext context, string input, IServiceProvider services)
         {
-            T value;
-            if (_tryParse(input, out value))
+            if (_tryParse(input, out T value))
                 return Task.FromResult(TypeReaderResult.FromSuccess(value));
             return Task.FromResult(TypeReaderResult.FromError(CommandError.ParseFailed, $"Failed to parse {typeof(T).Name}"));
         }

src/Discord.Net.Commands/Readers/RoleTypeReader.cs

@@ -9,7 +9,7 @@ namespace Discord.Commands
     internal class RoleTypeReader<T> : TypeReader
         where T : class, IRole
     {
-        public override Task<TypeReaderResult> Read(ICommandContext context, string input)
+        public override Task<TypeReaderResult> Read(ICommandContext context, string input, IServiceProvider services)
         {
             ulong id;
 

src/Discord.Net.Commands/Readers/TypeReader.cs

@@ -1,9 +1,10 @@
-using System.Threading.Tasks;
+using System;
+using System.Threading.Tasks;
 
 namespace Discord.Commands
 {
     public abstract class TypeReader
     {
-        public abstract Task<TypeReaderResult> Read(ICommandContext context, string input);
+        public abstract Task<TypeReaderResult> Read(ICommandContext context, string input, IServiceProvider services);
     }
 }

src/Discord.Net.Commands/Readers/UserTypeReader.cs

@@ -10,7 +10,7 @@ namespace Discord.Commands
     internal class UserTypeReader<T> : TypeReader
         where T : class, IUser
     {
-        public override async Task<TypeReaderResult> Read(ICommandContext context, string input)
+        public override async Task<TypeReaderResult> Read(ICommandContext context, string input, IServiceProvider services)
         {
             var results = new Dictionary<ulong, TypeReaderValue>();
             IReadOnlyCollection<IUser> channelUsers = (await context.Channel.GetUsersAsync(CacheMode.CacheOnly).Flatten().ConfigureAwait(false)).ToArray(); //TODO: must be a better way?
@@ -43,8 +43,7 @@ namespace Discord.Commands
             if (index >= 0)
             {
                 string username = input.Substring(0, index);
-                ushort discriminator;
-                if (ushort.TryParse(input.Substring(index + 1), out discriminator))
+                if (ushort.TryParse(input.Substring(index + 1), out ushort discriminator))
                 {
                     var channelUser = channelUsers.FirstOrDefault(x => x.DiscriminatorValue == discriminator &&
                         string.Equals(username, x.Username, StringComparison.OrdinalIgnoreCase));