Merge pull request #320 from appelemac/Ncalc

~calc command

NadekoBot/Modules/Searches/Commands/EvalCommand.cs

@@ -0,0 +1,85 @@
+using NadekoBot.Classes;
+using System;
+using Mathos.Parser;
+using System.Threading.Tasks;
+using Discord.Commands;
+using System.Text.RegularExpressions;
+
+namespace NadekoBot.Modules.Searches.Commands
+{
+    class EvalCommand : DiscordCommand
+    {
+        public EvalCommand(DiscordModule module) : base(module)
+        {
+        }
+
+        internal override void Init(CommandGroupBuilder cgb)
+        {
+            cgb.CreateCommand(Module.Prefix + "calculate")
+                .Alias(Module.Prefix + "calc")
+                .Description("Evaluate a mathematical expression.\n**Usage**: ~calc 1+1")
+                .Parameter("expression", ParameterType.Unparsed)
+                .Do(EvalFunc());
+        }
+
+
+        private CustomParser parser = new CustomParser();
+        private Func<CommandEventArgs, Task> EvalFunc() => async e =>
+        {
+            string expression = e.GetArg("expression")?.Trim();
+            if (string.IsNullOrWhiteSpace(expression))
+            {
+                return;
+            }
+            string answer = Evaluate(expression);
+            if (answer == null)
+            {
+                await e.Channel.SendMessage($"Expression {expression} failed to evaluate");
+                return;
+            }
+            await e.Channel.SendMessage($"`result: {answer}`");
+        };
+
+        private string Evaluate(string expression)
+        {
+            //check for factorial
+            expression = Regex.Replace(expression, @"\d+!", x => x.Value + "0");
+            try
+            {
+                string result = parser.Parse(expression).ToString();
+                return result;
+            }
+            catch (OverflowException e)
+            {
+                return $"Overflow error on {expression}";
+            }
+            catch (FormatException e)
+            {
+                return $"\"{expression}\" was not formatted correctly";
+            }
+        }
+
+        
+
+        class CustomParser : MathParser
+        {
+            public CustomParser() : base()
+            {
+                OperatorList.Add("!");
+                OperatorAction.Add("!", (x, y) => Factorial(x));
+            }
+
+            static decimal Factorial(decimal x)
+            {
+                decimal y = x-1;
+                while (y >0)
+                {
+                    x = x * y--;
+                }
+                return x;
+            }
+        }
+
+
+    }
+}

NadekoBot/Modules/Searches/SearchesModule.cs

@@ -27,6 +27,8 @@ namespace NadekoBot.Modules.Searches
             commands.Add(new StreamNotifications(this));
             commands.Add(new ConverterCommand(this));
             commands.Add(new RedditCommand(this));
+			commands.Add(new WowJokeCommand(this));
+            commands.Add(new EvalCommand(this));
             commands.Add(new WowJokeCommand(this));
             rng = new Random();
         }

NadekoBot/NadekoBot.csproj

@@ -99,6 +99,10 @@
       <HintPath>..\packages\Manatee.Trello.WebApi.1.0.1\lib\net45\Manatee.Trello.WebApi.dll</HintPath>
       <Private>True</Private>
     </Reference>
+    <Reference Include="MathParser, Version=1.0.10.1, Culture=neutral, processorArchitecture=MSIL">
+      <HintPath>..\packages\MathosParser.1.0.10.1\lib\MathParser.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
     <Reference Include="Newtonsoft.Json, Version=8.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL">
       <HintPath>..\packages\Newtonsoft.Json.8.0.3\lib\net45\Newtonsoft.Json.dll</HintPath>
       <Private>True</Private>
@@ -138,6 +142,7 @@
     <Compile Include="Modules\CustomReactions\CustomReactions.cs" />
     <Compile Include="Modules\Programming\Commands\HaskellRepl.cs" />
     <Compile Include="Modules\Programming\ProgrammingModule.cs" />
+    <Compile Include="Modules\Searches\Commands\EvalCommand.cs" />
     <Compile Include="Modules\Searches\Commands\IMDB\ImdbMovie.cs" />
     <Compile Include="Modules\Searches\Commands\IMDB\ImdbScraper.cs" />
     <Compile Include="Classes\IncidentsHandler.cs" />

NadekoBot/packages.config

@@ -5,6 +5,7 @@
   <package id="Manatee.Trello" version="1.8.2" targetFramework="net452" />
   <package id="Manatee.Trello.ManateeJson" version="1.4.0" targetFramework="net452" />
   <package id="Manatee.Trello.WebApi" version="1.0.1" targetFramework="net452" />
+  <package id="MathosParser" version="1.0.10.1" targetFramework="net452" />
   <package id="Microsoft.AspNet.WebApi.Client" version="5.2.3" targetFramework="net452" />
   <package id="Microsoft.AspNet.WebApi.Core" version="5.2.3" targetFramework="net452" />
   <package id="Newtonsoft.Json" version="8.0.3" targetFramework="net46" />