Adopt .NET naming and structure: CsMic.* namespaces, PascalCase projects and solution; update Coco namespace; update package id and NuGet publish target; adjust project refs and tests.

src/StandardLibrary/functions/FunctionBase.cs

@@ -0,0 +1,70 @@
+using CsMic;
+using FunctionValueType = CsMic.FunctionValueType;
+
+namespace CsMic.StandardLibrary.Functions
+{
+    public abstract class FunctionBase
+    {
+        public virtual IEnumerable<FunctionArgument> ExpectedArguments { get; }
+
+        public virtual FunctionValue ReturnValue
+        {
+            get
+
+            {
+                return FunctionValue.NUMBER;
+            }
+        }
+
+        public bool ArgumentCheck(params FunctionArgument[] args)
+        {
+            // Top level sanity checks.
+            if (args == null || args.Length != this.ExpectedArguments.Count())
+            {
+                return false;
+            }
+
+            // Check each argument against what is expected.
+            var expectedArgumentsArray = this.ExpectedArguments.ToArray();
+            for (int i = 0; i < args.Length; i++)
+            {
+                var expectedArgument = expectedArgumentsArray[i];
+                var argument = args[i];
+                if (argument.Value == null || argument.Value.Value == null || argument.Value.Type != expectedArgument.Value.Type)
+                {
+                    return false;
+                }
+
+                if (argument.Value.Type == FunctionValueType.Numeric && argument.Value.Value is not decimal)
+                {
+                    return false;
+                }
+
+                if (argument.Value.Type == FunctionValueType.String && argument.Value.Value is not string)
+                {
+                    return false;
+                }
+            }
+
+            // All checks passed.
+            return true;
+        }
+
+        public FunctionValue Execute(FunctionArgument[] args, Func<FunctionArgument[], FunctionValue> action)
+        {
+            if (!ArgumentCheck(args))
+            {
+                return FunctionValue.NONE;
+            }
+
+            try
+            {
+                return action(args);
+            }
+            catch
+            {
+                return FunctionValue.NONE;
+            }
+        }
+    }
+}