Cleaned up command builders and async func names

src/Discord.Net.Commands/Builders/CommandBuilder.cs

@@ -7,107 +7,109 @@ namespace Discord.Commands.Builders
 {
     public class CommandBuilder
     {
-        private List<PreconditionAttribute> preconditions;
+        private readonly List<PreconditionAttribute> _preconditions;
-        private List<ParameterBuilder> parameters;
+        private readonly List<ParameterBuilder> _parameters;
-        private List<string> aliases;
+        private readonly List<string> _aliases;
 
-        internal CommandBuilder(ModuleBuilder module)
+        public ModuleBuilder Module { get; }
-        {
+        internal Func<CommandContext, object[], IDependencyMap, Task> Callback { get; set; }
-            preconditions = new List<PreconditionAttribute>();
-            parameters = new List<ParameterBuilder>();
-            aliases = new List<string>();
-
-            Module = module;
-        }
 
         public string Name { get; set; }
         public string Summary { get; set; }
         public string Remarks { get; set; }
         public RunMode RunMode { get; set; }
         public int Priority { get; set; }
-        public Func<CommandContext, object[], IDependencyMap, Task> Callback { get; set; }
-        public ModuleBuilder Module { get; }
 
-        public List<PreconditionAttribute> Preconditions => preconditions;
+        public IReadOnlyList<PreconditionAttribute> Preconditions => _preconditions;
-        public List<ParameterBuilder> Parameters => parameters;
+        public IReadOnlyList<ParameterBuilder> Parameters => _parameters;
-        public List<string> Aliases => aliases;
+        public IReadOnlyList<string> Aliases => _aliases;
 
-        public CommandBuilder SetName(string name)
+        //Automatic
+        internal CommandBuilder(ModuleBuilder module)
+        {
+            Module = module;
+
+            _preconditions = new List<PreconditionAttribute>();
+            _parameters = new List<ParameterBuilder>();
+            _aliases = new List<string>();
+        }
+        //User-defined
+        internal CommandBuilder(ModuleBuilder module, string primaryAlias, Func<CommandContext, object[], IDependencyMap, Task> callback)
+            : this(module)
+        {
+            Discord.Preconditions.NotNull(primaryAlias, nameof(primaryAlias));
+            Discord.Preconditions.NotNull(callback, nameof(callback));
+
+            Callback = callback;
+            _aliases.Add(primaryAlias);
+        }
+
+        public CommandBuilder WithName(string name)
         {
             Name = name;
             return this;
         }
-
+        public CommandBuilder WithSummary(string summary)
-        public CommandBuilder SetSummary(string summary)
         {
             Summary = summary;
             return this;
         }
-
+        public CommandBuilder WithRemarks(string remarks)
-        public CommandBuilder SetRemarks(string remarks)
         {
             Remarks = remarks;
             return this;
         }
-
+        public CommandBuilder WithRunMode(RunMode runMode)
-        public CommandBuilder SetRunMode(RunMode runMode)
         {
             RunMode = runMode;
             return this;
         }
-
+        public CommandBuilder WithPriority(int priority)
-        public CommandBuilder SetPriority(int priority)
         {
             Priority = priority;
             return this;
         }
 
-        public CommandBuilder SetCallback(Func<CommandContext, object[], IDependencyMap, Task> callback)
+        public CommandBuilder AddAliases(params string[] aliases)
         {
-            Callback = callback;
+            _aliases.AddRange(aliases);
             return this;
         }
-
         public CommandBuilder AddPrecondition(PreconditionAttribute precondition)
         {
-            preconditions.Add(precondition);
+            _preconditions.Add(precondition);
             return this;
         }
-
+        public CommandBuilder AddParameter(string name, Type type, Action<ParameterBuilder> createFunc)
-        public CommandBuilder AddParameter(Action<ParameterBuilder> createFunc)
         {
-            var param = new ParameterBuilder();
+            var param = new ParameterBuilder(this, name, type);
             createFunc(param);
-            parameters.Add(param);
+            _parameters.Add(param);
             return this;
         }
-
+        internal CommandBuilder AddParameter(Action<ParameterBuilder> createFunc)
-        public CommandBuilder AddAliases(params string[] newAliases)
         {
-            aliases.AddRange(newAliases);
+            var param = new ParameterBuilder(this);
+            createFunc(param);
+            _parameters.Add(param);
             return this;
         }
 
         internal CommandInfo Build(ModuleInfo info, CommandService service)
         {
-            if (aliases.Count == 0)
+            //Default name to first alias
-                throw new InvalidOperationException("Commands require at least one alias to be registered");
-
-            if (Callback == null)
-                throw new InvalidOperationException("Commands require a callback to be built");
-
             if (Name == null)
-                Name = aliases[0];
+                Name = _aliases[0];
 
-            if (parameters.Count > 0)
+            if (_parameters.Count > 0)
             {
-                var lastParam = parameters[parameters.Count - 1];
+                var lastParam = _parameters[_parameters.Count - 1];
 
-                var firstMultipleParam = parameters.FirstOrDefault(x => x.Multiple);
+                var firstMultipleParam = _parameters.FirstOrDefault(x => x.IsMultiple);
                 if ((firstMultipleParam != null) && (firstMultipleParam != lastParam))
                     throw new InvalidOperationException("Only the last parameter in a command may have the Multiple flag.");
                 
-                var firstRemainderParam = parameters.FirstOrDefault(x => x.Remainder);
+                var firstRemainderParam = _parameters.FirstOrDefault(x => x.IsRemainder);
                 if ((firstRemainderParam != null) && (firstRemainderParam != lastParam))
                     throw new InvalidOperationException("Only the last parameter in a command may have the Remainder flag.");
             }

src/Discord.Net.Commands/Builders/ModuleBuilder.cs

@@ -1,96 +1,107 @@
 using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
+using System.Threading.Tasks;
 
 namespace Discord.Commands.Builders
 {
     public class ModuleBuilder
     {
-        private List<CommandBuilder> commands;
+        private readonly List<CommandBuilder> _commands;
-        private List<ModuleBuilder> submodules;
+        private readonly List<ModuleBuilder> _submodules;
-        private List<PreconditionAttribute> preconditions;
+        private readonly List<PreconditionAttribute> _preconditions;
-        private List<string> aliases;
+        private readonly List<string> _aliases;
-
-        public ModuleBuilder()
-        {
-            commands = new List<CommandBuilder>();
-            submodules = new List<ModuleBuilder>();
-            preconditions = new List<PreconditionAttribute>();
-            aliases = new List<string>();
-        }
-
-        internal ModuleBuilder(ModuleBuilder parent)
-            : this()
-        {
-            ParentModule = parent;
-        }
 
+        public CommandService Service { get; }
+        public ModuleBuilder Parent { get; }
         public string Name { get; set; }
         public string Summary { get; set; }
         public string Remarks { get; set; }
-        public ModuleBuilder ParentModule { get; }
 
-        public List<CommandBuilder> Commands => commands;
+        public IReadOnlyList<CommandBuilder> Commands => _commands;
-        public List<ModuleBuilder> Modules => submodules;
+        public IReadOnlyList<ModuleBuilder> Modules => _submodules;
-        public List<PreconditionAttribute> Preconditions => preconditions;
+        public IReadOnlyList<PreconditionAttribute> Preconditions => _preconditions;
-        public List<string> Aliases => aliases;
+        public IReadOnlyList<string> Aliases => _aliases;
 
-        public ModuleBuilder SetName(string name)
+        //Automatic
+        internal ModuleBuilder(CommandService service, ModuleBuilder parent)
+        {
+            Service = service;
+            Parent = parent;
+
+            _commands = new List<CommandBuilder>();
+            _submodules = new List<ModuleBuilder>();
+            _preconditions = new List<PreconditionAttribute>();
+            _aliases = new List<string>();
+        }
+        //User-defined
+        internal ModuleBuilder(CommandService service, ModuleBuilder parent, string primaryAlias)
+            : this(service, parent)
+        {
+            Discord.Preconditions.NotNull(primaryAlias, nameof(primaryAlias));
+
+            _aliases = new List<string> { primaryAlias };
+        }
+
+        public ModuleBuilder WithName(string name)
         {
             Name = name;
             return this;
         }
-
+        public ModuleBuilder WithSummary(string summary)
-        public ModuleBuilder SetSummary(string summary)
         {
             Summary = summary;
             return this;
         }
-
+        public ModuleBuilder WithRemarks(string remarks)
-        public ModuleBuilder SetRemarks(string remarks)
         {
             Remarks = remarks;
             return this;
         }
 
-        public ModuleBuilder AddAliases(params string[] newAliases)
+        public ModuleBuilder AddAlias(params string[] newAliases)
         {
-            aliases.AddRange(newAliases);
+            _aliases.AddRange(newAliases);
             return this;
         }
-
         public ModuleBuilder AddPrecondition(PreconditionAttribute precondition)
         {
-            preconditions.Add(precondition);
+            _preconditions.Add(precondition);
             return this;
         }
-
+        public ModuleBuilder AddCommand(string primaryAlias, Func<CommandContext, object[], IDependencyMap, Task> callback, Action<CommandBuilder> createFunc)
-        public ModuleBuilder AddCommand(Action<CommandBuilder> createFunc)
+        {
+            var builder = new CommandBuilder(this, primaryAlias, callback);
+            createFunc(builder);
+            _commands.Add(builder);
+            return this;
+        }
+        internal ModuleBuilder AddCommand(Action<CommandBuilder> createFunc)
         {
             var builder = new CommandBuilder(this);
             createFunc(builder);
-            commands.Add(builder);
+            _commands.Add(builder);
             return this;
         }
-
+        public ModuleBuilder AddModule(string primaryAlias, Action<ModuleBuilder> createFunc)
-        public ModuleBuilder AddSubmodule(Action<ModuleBuilder> createFunc)
         {
-            var builder = new ModuleBuilder(this);
+            var builder = new ModuleBuilder(Service, this, primaryAlias);
             createFunc(builder);
-            submodules.Add(builder);
+            _submodules.Add(builder);
+            return this;
+        }
+        internal ModuleBuilder AddModule(Action<ModuleBuilder> createFunc)
+        {
+            var builder = new ModuleBuilder(Service, this);
+            createFunc(builder);
+            _submodules.Add(builder);
             return this;
         }
 
         public ModuleInfo Build(CommandService service)
         {
-            if (aliases.Count == 0)
+            //Default name to first alias
-                throw new InvalidOperationException("Modules require at least one alias to be registered");
-
-            if (commands.Count == 0 && submodules.Count == 0)
-                throw new InvalidOperationException("Tried to build empty module");
-
             if (Name == null)
-                Name = aliases[0];
+                Name = _aliases[0];
 
             return new ModuleInfo(this, service);
         }

src/Discord.Net.Commands/Builders/ModuleClassBuilder.cs

@@ -40,11 +40,11 @@ namespace Discord.Commands
 
             foreach (var typeInfo in topLevelGroups)
             {
-                // this shouldn't be the case; may be safe to remove?
+                // TODO: This shouldn't be the case; may be safe to remove?
                 if (result.ContainsKey(typeInfo.AsType()))
                     continue;
 
-                var module = new ModuleBuilder();
+                var module = new ModuleBuilder(service, null);
 
                 BuildModule(module, typeInfo, service);
                 BuildSubTypes(module, typeInfo.DeclaredNestedTypes, builtTypes, service);
@@ -65,7 +65,7 @@ namespace Discord.Commands
                 if (builtTypes.Contains(typeInfo))
                     continue;
                 
-                builder.AddSubmodule((module) => {
+                builder.AddModule((module) => {
                     BuildModule(module, typeInfo, service);
                     BuildSubTypes(module, typeInfo.DeclaredNestedTypes, builtTypes, service);
                 });
@@ -88,17 +88,20 @@ namespace Discord.Commands
                 else if (attribute is RemarksAttribute)
                     builder.Remarks = (attribute as RemarksAttribute).Text;
                 else if (attribute is AliasAttribute)
-                    builder.AddAliases((attribute as AliasAttribute).Aliases);
+                    builder.AddAlias((attribute as AliasAttribute).Aliases);
                 else if (attribute is GroupAttribute)
                 {
                     var groupAttr = attribute as GroupAttribute;
                     builder.Name = builder.Name ?? groupAttr.Prefix;
-                    builder.AddAliases(groupAttr.Prefix);
+                    builder.AddAlias(groupAttr.Prefix);
                 }
                 else if (attribute is PreconditionAttribute)
                     builder.AddPrecondition(attribute as PreconditionAttribute);
             }
 
+            if (builder.Name == null)
+                builder.Name = typeInfo.Name;
+
             var validCommands = typeInfo.DeclaredMethods.Where(x => IsValidCommandDefinition(x));
 
             foreach (var method in validCommands)
@@ -168,7 +171,7 @@ namespace Discord.Commands
 
             builder.Name = paramInfo.Name;
 
-            builder.Optional = paramInfo.IsOptional;
+            builder.IsOptional = paramInfo.IsOptional;
             builder.DefaultValue = paramInfo.HasDefaultValue ? paramInfo.DefaultValue : null;
 
             foreach (var attribute in attributes)
@@ -178,7 +181,7 @@ namespace Discord.Commands
                     builder.Summary = (attribute as SummaryAttribute).Text;
                 else if (attribute is ParamArrayAttribute)
                 {
-                    builder.Multiple = true;
+                    builder.IsMultiple = true;
                     paramType = paramType.GetElementType();
                 }
                 else if (attribute is RemainderAttribute)
@@ -186,7 +189,7 @@ namespace Discord.Commands
                     if (position != count-1)
                         throw new InvalidOperationException("Remainder parameters must be the last parameter in a command.");
                     
-                    builder.Remainder = true;
+                    builder.IsRemainder = true;
                 }
             }
 

src/Discord.Net.Commands/Builders/ParameterBuilder.cs

@@ -1,100 +1,79 @@
 using System;
-using System.Threading.Tasks;
+using System.Reflection;
-using System.Collections.Generic;
 
 namespace Discord.Commands.Builders
 {
     public class ParameterBuilder
     {
-        public ParameterBuilder()
+        public CommandBuilder Command { get; }
-        { }
+        public string Name { get; internal set; }
-
+        public Type ParameterType { get; internal set; }
-        public ParameterBuilder(string name)
-        {
-            Name = name;
-        }
-
-        public string Name { get; set; }
-        public string Summary { get; set; }
-        public object DefaultValue { get; set; }
-        public Type ParameterType { get; set; }
 
         public TypeReader TypeReader { get; set; }
+        public bool IsOptional { get; set; }
+        public bool IsRemainder { get; set; }
+        public bool IsMultiple { get; set; }
+        public object DefaultValue { get; set; }
+        public string Summary { get; set; }
 
-        public bool Optional { get; set; }
+        //Automatic
-        public bool Remainder { get; set; }
+        internal ParameterBuilder(CommandBuilder command)
-        public bool Multiple { get; set; }
-
-        public ParameterBuilder SetName(string name)
         {
+            Command = command;
+        }
+        //User-defined
+        internal ParameterBuilder(CommandBuilder command, string name, Type type)
+            : this(command)
+        {
+            Preconditions.NotNull(name, nameof(name));
+
             Name = name;
-            return this;
+            SetType(type);
         }
 
-        public ParameterBuilder SetSummary(string summary)
+        internal void SetType(Type type)
+        {
+            TypeReader = Command.Module.Service.GetTypeReader(type);
+
+            if (type.GetTypeInfo().IsValueType)
+                DefaultValue = Activator.CreateInstance(type);
+            else if (type.IsArray)
+                type = ParameterType.GetElementType();
+            ParameterType = type;
+        }
+        
+        public ParameterBuilder WithSummary(string summary)
         {
             Summary = summary;
             return this;
         }
-
+        public ParameterBuilder WithDefault(object defaultValue)
-        public ParameterBuilder SetDefault<T>(T defaultValue)
         {
-            Optional = true;
             DefaultValue = defaultValue;            
-            ParameterType = typeof(T);
+            return this;
-
+        }
-            if (ParameterType.IsArray)
+        public ParameterBuilder WithIsOptional(bool isOptional)
-                ParameterType = ParameterType.GetElementType();
+        {
-
+            IsOptional = isOptional;
+            return this;
+        }
+        public ParameterBuilder WithIsRemainder(bool isRemainder)
+        {
+            IsRemainder = isRemainder;
+            return this;
+        }
+        public ParameterBuilder WithIsMultiple(bool isMultiple)
+        {
+            IsMultiple = isMultiple;
             return this;
         }
 
-        public ParameterBuilder SetType(Type parameterType)
+        internal ParameterInfo Build(CommandInfo info)
         {
-            ParameterType = parameterType; 
-            return this;
-        }
-
-        public ParameterBuilder SetTypeReader(TypeReader reader)
-        {
-            TypeReader = reader;
-            return this;
-        }
-
-        public ParameterBuilder SetOptional(bool isOptional)
-        {
-            Optional = isOptional;
-            return this;
-        }
-
-        public ParameterBuilder SetRemainder(bool isRemainder)
-        {
-            Remainder = isRemainder;
-            return this;
-        }
-
-        public ParameterBuilder SetMultiple(bool isMultiple)
-        {
-            Multiple = isMultiple;
-            return this;
-        }
-
-        internal ParameterInfo Build(CommandInfo info, CommandService service)
-        {
-            // TODO: should we throw when we don't have a name?
-            if (Name == null)
-                Name = "[unknown parameter]";
-
-            if (ParameterType == null)
-                throw new InvalidOperationException($"Could not build parameter {Name} from command {info.Name} - An invalid parameter type was given");
-
             if (TypeReader == null)
-                TypeReader = service.GetTypeReader(ParameterType);
+                throw new InvalidOperationException($"No default TypeReader found, one must be specified");
 
-            if (TypeReader == null)
+            return new ParameterInfo(this, info, Command.Module.Service);
-                throw new InvalidOperationException($"Could not build parameter {Name} from command {info.Name} - A valid TypeReader could not be found");
-
-            return new ParameterInfo(this, info, service);
         }
     }
 }

src/Discord.Net.Commands/CommandService.cs

@@ -67,12 +67,12 @@ namespace Discord.Commands
         }
 
         //Modules
-        public async Task<ModuleInfo> BuildModule(Action<ModuleBuilder> buildFunc)
+        public async Task<ModuleInfo> CreateModuleAsync(string primaryAlias, Action<ModuleBuilder> buildFunc)
         {
             await _moduleLock.WaitAsync().ConfigureAwait(false);
             try
             {
-                var builder = new ModuleBuilder();
+                var builder = new ModuleBuilder(this, null, primaryAlias);
                 buildFunc(builder);
 
                 var module = builder.Build(this);
@@ -83,7 +83,7 @@ namespace Discord.Commands
                 _moduleLock.Release();
             }
         }
-        public async Task<ModuleInfo> AddModule<T>()
+        public async Task<ModuleInfo> AddModuleAsync<T>()
         {
             await _moduleLock.WaitAsync().ConfigureAwait(false);
             try
@@ -107,7 +107,7 @@ namespace Discord.Commands
                 _moduleLock.Release();
             }
         }
-        public async Task<IEnumerable<ModuleInfo>> AddModules(Assembly assembly)
+        public async Task<IEnumerable<ModuleInfo>> AddModulesAsync(Assembly assembly)
         {
             await _moduleLock.WaitAsync().ConfigureAwait(false);
             try
@@ -141,7 +141,7 @@ namespace Discord.Commands
             return module;
         }
 
-        public async Task<bool> RemoveModule(ModuleInfo module)
+        public async Task<bool> RemoveModuleAsync(ModuleInfo module)
         {
             await _moduleLock.WaitAsync().ConfigureAwait(false);
             try
@@ -153,7 +153,7 @@ namespace Discord.Commands
                 _moduleLock.Release();
             }
         }
-        public async Task<bool> RemoveModule<T>()
+        public async Task<bool> RemoveModuleAsync<T>()
         {
             await _moduleLock.WaitAsync().ConfigureAwait(false);
             try
@@ -217,9 +217,9 @@ namespace Discord.Commands
                 return SearchResult.FromError(CommandError.UnknownCommand, "Unknown command.");
         }
 
-        public Task<IResult> Execute(CommandContext context, int argPos, IDependencyMap dependencyMap = null, MultiMatchHandling multiMatchHandling = MultiMatchHandling.Exception) 
+        public Task<IResult> ExecuteAsync(CommandContext context, int argPos, IDependencyMap dependencyMap = null, MultiMatchHandling multiMatchHandling = MultiMatchHandling.Exception) 
-            => Execute(context, context.Message.Content.Substring(argPos), dependencyMap, multiMatchHandling);
+            => ExecuteAsync(context, context.Message.Content.Substring(argPos), dependencyMap, multiMatchHandling);
-        public async Task<IResult> Execute(CommandContext context, string input, IDependencyMap dependencyMap = null, MultiMatchHandling multiMatchHandling = MultiMatchHandling.Exception)
+        public async Task<IResult> ExecuteAsync(CommandContext context, string input, IDependencyMap dependencyMap = null, MultiMatchHandling multiMatchHandling = MultiMatchHandling.Exception)
         {
             dependencyMap = dependencyMap ?? DependencyMap.Empty;
 
@@ -230,7 +230,7 @@ namespace Discord.Commands
             var commands = searchResult.Commands;
             for (int i = commands.Count - 1; i >= 0; i--)
             {
-                var preconditionResult = await commands[i].CheckPreconditions(context, dependencyMap).ConfigureAwait(false);
+                var preconditionResult = await commands[i].CheckPreconditionsAsync(context, dependencyMap).ConfigureAwait(false);
                 if (!preconditionResult.IsSuccess)
                 {
                     if (commands.Count == 1)
@@ -239,7 +239,7 @@ namespace Discord.Commands
                         continue;
                 }
 
-                var parseResult = await commands[i].Parse(context, searchResult, preconditionResult).ConfigureAwait(false);
+                var parseResult = await commands[i].ParseAsync(context, searchResult, preconditionResult).ConfigureAwait(false);
                 if (!parseResult.IsSuccess)
                 {
                     if (parseResult.Error == CommandError.MultipleMatches)

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

@@ -40,16 +40,20 @@ namespace Discord.Commands
             RunMode = builder.RunMode;
             Priority = builder.Priority;
             
-            Aliases = module.Aliases.Permutate(builder.Aliases, (first, second) => first + " " + second).ToImmutableArray();
+            if (module.Aliases.Count != 0)
+                Aliases = module.Aliases.Permutate(builder.Aliases, (first, second) => first + " " + second).ToImmutableArray();
+            else
+                Aliases = builder.Aliases.ToImmutableArray();
+
             Preconditions = builder.Preconditions.ToImmutableArray();
 
-            Parameters = builder.Parameters.Select(x => x.Build(this, service)).ToImmutableArray();
+            Parameters = builder.Parameters.Select(x => x.Build(this)).ToImmutableArray();
-            HasVarArgs = builder.Parameters.Count > 0 ? builder.Parameters[builder.Parameters.Count - 1].Multiple : false;
+            HasVarArgs = builder.Parameters.Count > 0 ? builder.Parameters[builder.Parameters.Count - 1].IsMultiple : false;
 
             _action = builder.Callback;
         }
 
-        public async Task<PreconditionResult> CheckPreconditions(CommandContext context, IDependencyMap map = null)
+        public async Task<PreconditionResult> CheckPreconditionsAsync(CommandContext context, IDependencyMap map = null)
         {
             if (map == null)
                 map = DependencyMap.Empty;
@@ -71,7 +75,7 @@ namespace Discord.Commands
             return PreconditionResult.FromSuccess();
         }
 
-        public async Task<ParseResult> Parse(CommandContext context, SearchResult searchResult, PreconditionResult? preconditionResult = null)
+        public async Task<ParseResult> ParseAsync(CommandContext context, SearchResult searchResult, PreconditionResult? preconditionResult = null)
         {
             if (!searchResult.IsSuccess)
                 return ParseResult.FromError(searchResult);
@@ -114,9 +118,9 @@ namespace Discord.Commands
                 paramList[i] = parseResult.ParamValues[i].Values.First().Value;
             }
 
-            return Execute(context, argList, paramList, map);
+            return ExecuteAsync(context, argList, paramList, map);
         }
-        public async Task<ExecuteResult> Execute(CommandContext context, IEnumerable<object> argList, IEnumerable<object> paramList, IDependencyMap map)
+        public async Task<ExecuteResult> ExecuteAsync(CommandContext context, IEnumerable<object> argList, IEnumerable<object> paramList, IDependencyMap map)
         {
             if (map == null)
                 map = DependencyMap.Empty;
@@ -163,7 +167,7 @@ namespace Discord.Commands
 
             if (HasVarArgs)
             {
-                var func = _arrayConverters.GetOrAdd(Parameters[Parameters.Count - 1].ParameterType, t =>
+                var func = _arrayConverters.GetOrAdd(Parameters[Parameters.Count - 1].Type, t =>
                 {
                     var method = _convertParamsMethod.MakeGenericMethod(t);
                     return (Func<IEnumerable<object>, object>)method.CreateDelegate(typeof(Func<IEnumerable<object>, object>));

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

@@ -1,4 +1,3 @@
-using System;
 using System.Linq;
 using System.Collections.Generic;
 using System.Collections.Immutable;
@@ -41,11 +40,11 @@ namespace Discord.Commands
             Stack<ModuleBuilder> builderStack = new Stack<ModuleBuilder>();
             builderStack.Push(builder);
 
-            ModuleBuilder parent = builder.ParentModule;
+            ModuleBuilder parent = builder.Parent;
             while (parent != null)
             {
                 builderStack.Push(parent);
-                parent = parent.ParentModule;
+                parent = parent.Parent;
             }
 
             while (builderStack.Count() > 0)
@@ -82,7 +81,7 @@ namespace Discord.Commands
             while (parent != null)
             {
                 result.AddRange(parent.Preconditions);
-                parent = parent.ParentModule;
+                parent = parent.Parent;
             }
 
             return result;

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

@@ -16,11 +16,11 @@ namespace Discord.Commands
 
             Name = builder.Name;
             Summary = builder.Summary;
-            IsOptional = builder.Optional;
+            IsOptional = builder.IsOptional;
-            IsRemainder = builder.Remainder;
+            IsRemainder = builder.IsRemainder;
-            IsMultiple = builder.Multiple;
+            IsMultiple = builder.IsMultiple;
 
-            ParameterType = builder.ParameterType;
+            Type = builder.ParameterType;
             DefaultValue = builder.DefaultValue;
 
             _reader = builder.TypeReader;
@@ -32,7 +32,7 @@ namespace Discord.Commands
         public bool IsOptional { get; }
         public bool IsRemainder { get; }
         public bool IsMultiple { get; }
-        public Type ParameterType { get; }
+        public Type Type { get; }
         public object DefaultValue { get; }
 
         public async Task<TypeReaderResult> Parse(CommandContext context, string input)

src/Discord.Net.Commands/Map/CommandMap.cs

@@ -1,95 +1,39 @@
-using System.Collections.Concurrent;
+using System.Collections.Generic;
-using System.Collections.Generic;
-using System.Linq;
 
 namespace Discord.Commands
 {
     internal class CommandMap
     {
-        static readonly char[] _whitespaceChars = new char[] { ' ', '\r', '\n' };
+        private readonly CommandMapNode _root;
-        private readonly object _lockObj = new object();
+        private static readonly string[] _blankAliases = new[] { "" };
-
-        private readonly ConcurrentDictionary<string, CommandMapNode> _nodes;
 
         public CommandMap()
         {
-            _nodes = new ConcurrentDictionary<string, CommandMapNode>();
+            _root = new CommandMapNode("");
         }
 
         public void AddCommand(CommandInfo command)
         {
-            foreach (string text in command.Aliases)
+            foreach (string text in GetAliases(command))
-            {
+                _root.AddCommand(text, 0, command);
-                int nextSpace = NextWhitespace(text);
-                string name;
-
-                if (nextSpace == -1)
-                    name = text;
-                else
-                    name = text.Substring(0, nextSpace);
-
-                lock (_lockObj)
-                {
-                    var nextNode = _nodes.GetOrAdd(name, x => new CommandMapNode(x));
-                    nextNode.AddCommand(nextSpace == -1 ? "" : text, nextSpace + 1, command);
-                }
-            }
         }
         public void RemoveCommand(CommandInfo command)
         {
-            foreach (string text in command.Aliases)
+            foreach (string text in GetAliases(command))
-            {
+                _root.RemoveCommand(text, 0, command);
-                int nextSpace = NextWhitespace(text);
-                string name;
-
-                if (nextSpace == -1)
-                    name = text;
-                else
-                    name = text.Substring(0, nextSpace);
-
-                lock (_lockObj)
-                {
-                    CommandMapNode nextNode;
-                    if (_nodes.TryGetValue(name, out nextNode))
-                    {
-                        nextNode.RemoveCommand(nextSpace == -1 ? "" : text, nextSpace + 1, command);
-                        if (nextNode.IsEmpty)
-                            _nodes.TryRemove(name, out nextNode);
-                    }
-                }
-            }
         }
 
         public IEnumerable<CommandInfo> GetCommands(string text)
         {
-            int nextSpace = NextWhitespace(text);
+            return _root.GetCommands(text, 0);
-            string name;
-
-            if (nextSpace == -1)
-                name = text;
-            else
-                name = text.Substring(0, nextSpace);
-
-            lock (_lockObj)
-            {
-                CommandMapNode nextNode;
-                if (_nodes.TryGetValue(name, out nextNode))
-                    return nextNode.GetCommands(text, nextSpace + 1);
-                else
-                    return Enumerable.Empty<CommandInfo>();
-            }
         }
 
-        private static int NextWhitespace(string text)
+        private IReadOnlyList<string> GetAliases(CommandInfo command)
         {
-            int lowest = int.MaxValue;
+            var aliases = command.Aliases;
-            for (int i = 0; i < _whitespaceChars.Length; i++)
+            if (aliases.Count == 0)
-            {
+                return _blankAliases;
-                int index = text.IndexOf(_whitespaceChars[i]);
+            return aliases;
-                if (index != -1 && index < lowest)
-                    lowest = index;
-            }
-            return (lowest != int.MaxValue) ? lowest : -1;
         }
     }
 }

src/Discord.Net.Commands/Map/CommandMapNode.cs

@@ -1,4 +1,5 @@
-using System.Collections.Concurrent;
+using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 
@@ -6,6 +7,8 @@ namespace Discord.Commands
 {
     internal class CommandMapNode
     {
+        private static readonly char[] _whitespaceChars = new char[] { ' ', '\r', '\n' };
+
         private readonly ConcurrentDictionary<string, CommandMapNode> _nodes;
         private readonly string _name;
         private readonly object _lockObj = new object();
@@ -22,13 +25,17 @@ namespace Discord.Commands
 
         public void AddCommand(string text, int index, CommandInfo command)
         {
-            int nextSpace = text.IndexOf(' ', index);
+            int nextSpace = NextWhitespace(text, index);
             string name;
 
             lock (_lockObj)
             {
                 if (text == "")
+                {
+                    if (_name == "")
+                        throw new InvalidOperationException("Cannot add commands to the root node.");
                     _commands = _commands.Add(command);
+                }
                 else
                 {
                     if (nextSpace == -1)
@@ -43,7 +50,7 @@ namespace Discord.Commands
         }
         public void RemoveCommand(string text, int index, CommandInfo command)
         {
-            int nextSpace = text.IndexOf(' ', index);
+            int nextSpace = NextWhitespace(text, index);
             string name;
 
             lock (_lockObj)
@@ -70,7 +77,7 @@ namespace Discord.Commands
 
         public IEnumerable<CommandInfo> GetCommands(string text, int index)
         {
-            int nextSpace = text.IndexOf(' ', index);
+            int nextSpace = NextWhitespace(text, index);
             string name;
 
             var commands = _commands;
@@ -92,5 +99,17 @@ namespace Discord.Commands
                 }
             }
         }
+
+        private static int NextWhitespace(string text, int startIndex)
+        {
+            int lowest = int.MaxValue;
+            for (int i = 0; i < _whitespaceChars.Length; i++)
+            {
+                int index = text.IndexOf(_whitespaceChars[i], startIndex);
+                if (index != -1 && index < lowest)
+                    lowest = index;
+            }
+            return (lowest != int.MaxValue) ? lowest : -1;
+        }
     }
 }

src/Discord.Net.Core/Utils/Preconditions.cs

@@ -5,47 +5,51 @@ namespace Discord
     internal static class Preconditions
     {
         //Objects
-        public static void NotNull<T>(T obj, string name, string msg = null) where T : class { if (obj == null) throw new ArgumentNullException(name); }
+        public static void NotNull<T>(T obj, string name, string msg = null) where T : class { if (obj == null) throw CreateNotNullException(name, msg); }
-        public static void NotNull<T>(Optional<T> obj, string name, string msg = null) where T : class { if (obj.IsSpecified && obj.Value == null) throw new ArgumentNullException(name); }
+        public static void NotNull<T>(Optional<T> obj, string name, string msg = null) where T : class { if (obj.IsSpecified && obj.Value == null) throw CreateNotNullException(name, msg); }
+
+        private static ArgumentNullException CreateNotNullException(string name, string msg)
+        {
+            if (msg == null) return new ArgumentNullException(name);
+            else return new ArgumentNullException(name, msg);
+        }
 
         //Strings
-        public static void NotEmpty(string obj, string name, string msg = null) { if (obj.Length == 0) throw new ArgumentException("Argument cannot be empty.", name); }
+        public static void NotEmpty(string obj, string name, string msg = null) { if (obj.Length == 0) throw CreateNotEmptyException(name, msg); }
-        public static void NotEmpty(Optional<string> obj, string name, string msg = null) { if (obj.IsSpecified && obj.Value.Length == 0) throw new ArgumentException("Argument cannot be empty.", name); }
+        public static void NotEmpty(Optional<string> obj, string name, string msg = null) { if (obj.IsSpecified && obj.Value.Length == 0) throw CreateNotEmptyException(name, msg); }
         public static void NotNullOrEmpty(string obj, string name, string msg = null)
         {
-            if (obj == null)
+            if (obj == null) throw CreateNotNullException(name, msg);
-                throw new ArgumentNullException(name);
+            if (obj.Length == 0) throw CreateNotEmptyException(name, msg);
-            if (obj.Length == 0)
-                throw new ArgumentException("Argument cannot be empty.", name);
         }
         public static void NotNullOrEmpty(Optional<string> obj, string name, string msg = null)
         {
             if (obj.IsSpecified)
             {
-                if (obj.Value == null)
+                if (obj.Value == null) throw CreateNotNullException(name, msg);
-                    throw new ArgumentNullException(name);
+                if (obj.Value.Length == 0) throw CreateNotEmptyException(name, msg);
-                if (obj.Value.Length == 0)
-                    throw new ArgumentException("Argument cannot be empty.", name);
             }
         }
         public static void NotNullOrWhitespace(string obj, string name, string msg = null)
         {
-            if (obj == null)
+            if (obj == null) throw CreateNotNullException(name, msg);
-                throw new ArgumentNullException(name);
+            if (obj.Trim().Length == 0) throw CreateNotEmptyException(name, msg);
-            if (obj.Trim().Length == 0)
-                throw new ArgumentException("Argument cannot be blank.", name);
         }
         public static void NotNullOrWhitespace(Optional<string> obj, string name, string msg = null)
         {
             if (obj.IsSpecified)
             {
-                if (obj.Value == null)
+                if (obj.Value == null) throw CreateNotNullException(name, msg);
-                    throw new ArgumentNullException(name);
+                if (obj.Value.Trim().Length == 0) throw CreateNotEmptyException(name, msg);
-                if (obj.Value.Trim().Length == 0)
-                    throw new ArgumentException("Argument cannot be blank.", name);
             }
         }
 
+        private static ArgumentException CreateNotEmptyException(string name, string msg)
+        {
+            if (msg == null) return new ArgumentException(name, "Argument cannot be blank.");
+            else return new ArgumentException(name, msg);
+        }
+
         //Numerics
         public static void NotEqual(sbyte obj, sbyte value, string name, string msg = null) { if (obj == value) throw CreateNotEqualException(name, msg, value); }
         public static void NotEqual(byte obj, byte value, string name, string msg = null) { if (obj == value) throw CreateNotEqualException(name, msg, value); }
@@ -82,10 +86,8 @@ namespace Discord
 
         private static ArgumentException CreateNotEqualException<T>(string name, string msg, T value)
         {
-            if (msg == null)
+            if (msg == null) return new ArgumentException($"Value may not be equal to {value}", name);
-                throw new ArgumentException($"Value may not be equal to {value}", name);
+            else return new ArgumentException(msg, name);
-            else
-                throw new ArgumentException(msg, name);
         }
 
         public static void AtLeast(sbyte obj, sbyte value, string name, string msg = null) { if (obj < value) throw CreateAtLeastException(name, msg, value); }
@@ -107,10 +109,8 @@ namespace Discord
 
         private static ArgumentException CreateAtLeastException<T>(string name, string msg, T value)
         {
-            if (msg == null)
+            if (msg == null) return new ArgumentException($"Value must be at least {value}", name);
-                throw new ArgumentException($"Value must be at least {value}", name);
+            else return new ArgumentException(msg, name);
-            else
-                throw new ArgumentException(msg, name);
         }
 
         public static void GreaterThan(sbyte obj, sbyte value, string name, string msg = null) { if (obj <= value) throw CreateGreaterThanException(name, msg, value); }
@@ -132,10 +132,8 @@ namespace Discord
 
         private static ArgumentException CreateGreaterThanException<T>(string name, string msg, T value)
         {
-            if (msg == null)
+            if (msg == null) return new ArgumentException($"Value must be greater than {value}", name);
-                throw new ArgumentException($"Value must be greater than {value}", name);
+            else return new ArgumentException(msg, name);
-            else
-                throw new ArgumentException(msg, name);
         }
 
         public static void AtMost(sbyte obj, sbyte value, string name, string msg = null) { if (obj > value) throw CreateAtMostException(name, msg, value); }
@@ -157,10 +155,8 @@ namespace Discord
 
         private static ArgumentException CreateAtMostException<T>(string name, string msg, T value)
         {
-            if (msg == null)
+            if (msg == null) return new ArgumentException($"Value must be at most {value}", name);
-                throw new ArgumentException($"Value must be at most {value}", name);
+            else return new ArgumentException(msg, name);
-            else
-                throw new ArgumentException(msg, name);
         }
 
         public static void LessThan(sbyte obj, sbyte value, string name, string msg = null) { if (obj >= value) throw CreateLessThanException(name, msg, value); }
@@ -182,10 +178,8 @@ namespace Discord
 
         private static ArgumentException CreateLessThanException<T>(string name, string msg, T value)
         {
-            if (msg == null)
+            if (msg == null) return new ArgumentException($"Value must be less than {value}", name);
-                throw new ArgumentException($"Value must be less than {value}", name);
+            else return new ArgumentException(msg, name);
-            else
-                throw new ArgumentException(msg, name);
         }
     }
 }