add VariableArgument<T>

Author: Elektryk-Andrzej

Code/ArgumentSystem/Arguments/VariableArgument.cs

@@ -1,5 +1,6 @@
 using JetBrains.Annotations;
 using SER.Code.ArgumentSystem.BaseArguments;
+using SER.Code.Helpers.Extensions;
 using SER.Code.Helpers.ResultSystem;
 using SER.Code.TokenSystem.Tokens;
 using SER.Code.TokenSystem.Tokens.VariableTokens;
@@ -24,4 +25,23 @@ public DynamicTryGet<Variable> GetConvertSolution(BaseToken token)
 
         return new(() => variableToken.TryGetVariable());
     }
+}
+
+public class VariableArgument<T>(string name) : Argument(name) where T : Variable
+{
+    public override string InputDescription => $"A {typeof(T).FriendlyTypeName()}";
+
+    [UsedImplicitly]
+    public DynamicTryGet<T> GetConvertSolution(BaseToken token)
+    {
+        if (token is not VariableToken variableToken)
+        {
+            return $"Value '{token.RawRep}' is not a variable.";
+        }
+
+        return new(() => variableToken
+                .TryGetVariable()
+                .SuccessTryCast<Variable, T>()
+        );
+    }
 }

Code/ArgumentSystem/ProvidedArguments.cs

@@ -22,6 +22,11 @@ public class ProvidedArguments(Method method)
 {
     private Dictionary<(string name, Type type), List<DynamicTryGet>> ArgumentValues { get; } = [];
 
+    public T GetVariable<T>(string argName) where T : Variable
+    {
+        return GetValue<T, VariableArgument<T>>(argName);
+    }
+    
     public Database GetDatabase(string argName)
     {
         return GetValue<Database, DatabaseArgument>(argName);