Message reporting if indexable value does not exist

Upsilon/BaseTypes/IIndexable.cs

@@ -1,11 +1,12 @@
 using Upsilon.Evaluator;
+using Upsilon.Text;
 
 namespace Upsilon.BaseTypes
 {
     internal interface IIndexable
     {
-        LuaType Get(string s, EvaluationScope scope);
+        LuaType Get(Diagnostics diagnostics, TextSpan span, string s, EvaluationScope scope);
-        void Set(string s, LuaType value);
+        void Set(Diagnostics diagnostics, TextSpan span, string s, LuaType value);
     }
 
     internal interface IScopeOwner

Upsilon/BaseTypes/LuaString.cs

@@ -1,6 +1,7 @@
 using System;
 using Upsilon.BaseTypes.Number;
 using Upsilon.Evaluator;
+using Upsilon.Text;
 
 namespace Upsilon.BaseTypes
 {
@@ -78,13 +79,13 @@ namespace Upsilon.BaseTypes
             return Value;
         }
 
-        public LuaType Get(string s, EvaluationScope scope)
+        public LuaType Get(Diagnostics diagnostics, TextSpan span, string s, EvaluationScope scope)
         {
             var i = int.Parse(s);
             return new LuaString(Value[i - 1].ToString());
         }
 
-        public void Set(string s, LuaType value)
+        public void Set(Diagnostics diagnostics, TextSpan span, string s, LuaType value)
         {
             throw new NotSupportedException();
         }

Upsilon/BaseTypes/LuaTable.cs

@@ -1,6 +1,7 @@
 using System.Linq;
 using Upsilon.Binder;
 using Upsilon.Evaluator;
+using Upsilon.Text;
 
 namespace Upsilon.BaseTypes
 {
@@ -20,19 +21,19 @@ namespace Upsilon.BaseTypes
             return EvaluationScope.Variables.ToDictionary(x => x.Key, x => x.Value.ToCSharpObject());
         }
 
-
+        public LuaType Get(Diagnostics diagnostics, TextSpan span, string s, EvaluationScope scope)
-        public LuaType Get(string s, EvaluationScope scope)
         {
             if (EvaluationScope.TryGet(s, out var o))
             {
                 return o;
             }
+            diagnostics.LogError("Cannot find member 's' on Table", span);
             return new LuaNull();
         }
 
-        public void Set(string s, LuaType obj)
+        public void Set(Diagnostics diagnostics, TextSpan span, string s, LuaType value)
         {
-            EvaluationScope.Set(new VariableSymbol(s, obj.Type, false), obj);
+            EvaluationScope.Set(new VariableSymbol(s, value.Type, false), value);
         }
     }
 }

Upsilon/BaseTypes/UserData/UserData.cs

@@ -1,4 +1,5 @@
 using Upsilon.Evaluator;
+using Upsilon.Text;
 
 namespace Upsilon.BaseTypes.UserData
 {
@@ -19,14 +20,23 @@ namespace Upsilon.BaseTypes.UserData
             return Value;
         }
 
-        public LuaType Get(string s, EvaluationScope scope)
+        public LuaType Get(Diagnostics diagnostics, TextSpan span, string s, EvaluationScope scope)
         {
-            return _typeInfo.Get(Value, s);
+            var (type, failed) = _typeInfo.Get(Value, s);
+            if (failed)
+            {
+                diagnostics.LogError($"Cannot find member '{s}' on type '{Value.GetType()}'", span);
+            }
+            return type;
         }
 
-        public void Set(string s, LuaType value)
+        public void Set(Diagnostics diagnostics, TextSpan span, string s, LuaType value)
         {
-            _typeInfo.Set(Value, s, value);
+            var failed = _typeInfo.Set(Value, s, value);
+            if (failed)
+            {
+                diagnostics.LogError($"Cannot find member '{s}' on type '{Value.GetType()}'", span);
+            }
         }
     }
 }

Upsilon/BaseTypes/UserData/UserDataType.cs

@@ -19,40 +19,43 @@ namespace Upsilon.BaseTypes.UserData
         private Dictionary<string, PropertyInfo> Properties { get; }
         private Dictionary<string, MethodInfo> Methods { get; }
 
-        public LuaType Get(object value, string member)
+        public (LuaType Type, bool Failed) Get(object value, string member)
         {
             if (value.GetType() != Type)
-                return null;
+                return (null, true);
             member = member.ToLowerInvariant();
             if (Variables.TryGetValue(member, out var info))
             {
-                return info.GetValue(value).ToLuaType();
+                return (info.GetValue(value).ToLuaType(), false);
             }
             if (Properties.TryGetValue(member, out var property))
             {
-                return property.GetValue(value).ToLuaType();
+                return (property.GetValue(value).ToLuaType(), false);
             }
             if (Methods.TryGetValue(member, out var method))
             {
-                return new LuaMethodInfoFunction(method, value);
+                return (new LuaMethodInfoFunction(method, value), false);
+            }
+            return (null, true);
         }
 
-            return null;
+        public bool Set(object value, string member, LuaType newValue)
-        }
-
-        public void Set(object value, string member, LuaType newValue)
         {
             member = member.ToLowerInvariant();
             if (value.GetType() != Type)
-                return;
+                return true;
             if (Variables.TryGetValue(member, out var info))
             {
                 info.SetValue(value, newValue.ToCSharpObject());
+                return false;
             }
             if (Properties.TryGetValue(member, out var property))
             {
                 property.SetValue(value, newValue.ToCSharpObject());
-            }
+                return false;
+            }
+
+            return true;
         }
     }
 }

Upsilon/Binder/BoundNode.cs

@@ -1,7 +1,10 @@
+using Upsilon.Text;
+
 namespace Upsilon.Binder
 {
     public abstract class BoundNode
     {
         public abstract BoundKind Kind { get; }
+        public TextSpan Span { get; protected set; }
     }
 }

Upsilon/Evaluator/Evaluator.cs

@@ -304,7 +304,6 @@ namespace Upsilon.Evaluator
 
         private LuaType EvaluateTableExpression(BoundTableExpression e)
         {
-            var dic = new Dictionary<VariableSymbol, LuaType>();
             var tableScope = EvaluationScope.CreateWithGetOnlyParent(Scope);
             var innerEvaluator = new Evaluator(_diagnostics, tableScope);
             var currentPos = 1;
@@ -347,7 +346,7 @@ namespace Upsilon.Evaluator
                 scope = scopeOwner.EvaluationScope;
             }
             var indexer   = EvaluateExpression(e.Index);
-            return indexable.Get(indexer.ToString(), scope);
+            return indexable.Get(_diagnostics, e.Span, indexer.ToString(), scope);
         }
         private LuaType EvaluateFullStopIndexExpression(BoundFullStopIndexExpression e)
         {
@@ -363,7 +362,7 @@ namespace Upsilon.Evaluator
                 scope = scopeOwner.EvaluationScope;
             }
 
-            return indexable.Get(e.Index, scope);
+            return indexable.Get(_diagnostics, e.Span, e.Index, scope);
         }
 
         private void EvaluateTableAssignmentStatement(BoundTableAssigmentStatement e)
@@ -386,7 +385,7 @@ namespace Upsilon.Evaluator
             {
                 throw new Exception("Cant assign to that");
             }
-            indexable.Set(index.ToString(), value);
+            indexable.Set(_diagnostics, e.Span, index.ToString(), value);
         }
     }
 }

UpsilonTests/TableTests.cs

@@ -54,8 +54,7 @@ return table[""test""]
             var script = new Script(input);
             Assert.Empty(script.Diagnostics.Messages);
             var evaluated = script.Evaluate();
-            Assert.Empty(script.Diagnostics.Messages);
+            Assert.Single(script.Diagnostics.Messages);
-            Assert.Null(evaluated);
         }
 
         [Fact]

UpsilonTests/UserDataTests.cs

@@ -25,6 +25,7 @@ namespace UpsilonTests
         {
             public string FieldString = "TestField";
             public string FieldStringSet;
+            private string _privateTestField = "hidden";
 
             public bool TestMethodHasRun { get; private set; }
             public void TestMethod()
@@ -104,5 +105,21 @@ end
             Assert.Empty(script.Diagnostics.Messages);
             Assert.Equal(result, 120);
         }
+
+        [Fact]
+        public void CantAccessHiddenFields()
+        {
+            var obj = new UserDataHelper();
+            const string input = @"
+function test(o)
+    return o._privateTestField
+end
+";
+            var script = new Script(input);
+            Assert.Empty(script.Diagnostics.Messages);
+            script.EvaluateFunction("test", new[] {obj});
+            Assert.Single(script.Diagnostics.Messages);
+        }
+
     }
 }