Adding functions to Standard Library

src/StandardLibrary/Functions/Random/RandomNormalSpread.cs

@@ -0,0 +1,43 @@
+using CSMic;
+using CSMic.StandardLibrary.Functions.Random;
+
+namespace CSMic.StandardLibrary.Functions.Random
+{
+    public class RandomNormalSpread : RandomBase, ICodedFunction
+    {
+        public string Name
+        {
+            get
+            {
+                return "randns";
+            }
+        }
+
+        public override IEnumerable<FunctionArgument> ExpectedArguments
+        {
+            get
+            {
+                yield return new FunctionArgument("lower", FunctionValue.NUMBER);
+                yield return new FunctionArgument("upper", FunctionValue.NUMBER);
+            }
+        }
+
+        public FunctionValue Execute(params FunctionArgument[] args)
+        {
+            return base.Execute(args, (_args) =>
+            {
+                var inputLower = _args[0].Value;
+                var inputUpper = _args[1].Value;
+                decimal lower = Convert.ToDecimal(inputLower.Value);
+                decimal upper = Convert.ToDecimal(inputUpper.Value);
+
+                if(upper <= lower)
+                {
+                    return FunctionValue.ZERO;
+                }
+
+                return new FunctionValue(FunctionValueType.Numeric, NextDecimalNormal() * (upper - lower));
+            });
+        }
+    }
+}