Initial interpreter implemenation

--HG--
branch : dev

src/Orchard.Tests.Modules/SimpleScripting/EvaluatorTests.cs

@@ -1,4 +1,5 @@
-using NUnit.Framework;
+using System;
+using NUnit.Framework;
 using Orchard.Widgets.SimpleScripting;
 using Orchard.Widgets.SimpleScripting.Compiler;
 
@@ -7,8 +8,25 @@ namespace Orchard.Tests.Modules.SimpleScriptingTests {
     public class EvaluatorTests {
         [Test]
         public void EvaluateSimpleConstant() {
-            var tree = new Parser("1*2+3").Parse();
+            var result = EvaluateSimpleExpression("true and true");
+            Assert.That(result.HasErrors, Is.False);
+            Assert.That(result.Value, Is.EqualTo(true));
+        }
 
+        [Test]
+        public void EvaluateSimpleArithmetic() {
+            var result = EvaluateSimpleExpression("1 + 2 * 3 - 6 / 2");
+            Assert.That(result.HasErrors, Is.False);
+            Assert.That(result.Value, Is.EqualTo(4));
+        }
+
+        private EvaluationResult EvaluateSimpleExpression(string expression) {
+            var ast = new Parser(expression).Parse();
+            var result = new Interpreter().Evalutate(new EvaluationContext {
+                Tree = ast,
+                MethodInvocationCallback = (m, args) => null
+            });
+            return result;
         }
     }
 }