improve dictionary support

Directory.Build.props

@@ -9,7 +9,7 @@
 	<Product>Simpra</Product>
 	<Company>ALTA Software llc.</Company>
 	<Copyright>Copyright © 2024 ALTA Software llc.</Copyright>
-	<Version>1.0.12</Version>
+	<Version>1.0.13</Version>
   </PropertyGroup>
 
   <PropertyGroup>

src/AltaSoft.Simpra/Visitor/SimpraParserVisitor.cs

@@ -263,6 +263,14 @@ public Expression VisitIndexAccess(SimpraParser.IndexAccessContext context)
             objectType = left.Type;
         }
 
+        // Handle IDictionary<TKey, TValue> (including Dictionary<,>)
+        var isDictionary = objectType.IsIReadOnlyDictionaryT();
+
+        if (isDictionary)
+        {
+            return HandleDictionaryIndexAccess(context, objectType, index, left);
+        }
+
         // Handle indexable types (e.g., List<T>)
         var defaultIndexer = objectType
             .GetProperties()
@@ -552,4 +560,21 @@ public Expression VisitArray(SimpraParser.ArrayContext context)
     {
         return NewSimpraList(context.exp().Select(Visit), context);
     }
+
+    private static Expression HandleDictionaryIndexAccess(SimpraParser.IndexAccessContext context, Type objectType, Expression index, Expression left)
+    {
+        var keyType = objectType.GetGenericArguments()[0];
+        var valueType = objectType.GetGenericArguments()[1];
+        var tryGetValueMethod = objectType.GetMethod("TryGetValue", [keyType, valueType.MakeByRefType()])!;
+
+        var keyExpr = index.Type != keyType ? Expression.Convert(index, keyType) : index;
+        var valueVar = Expression.Variable(valueType, "dictValue");
+
+        var tryGetValueCall = Expression.Call(left, tryGetValueMethod, keyExpr, valueVar);
+
+        var defaultValue = Expression.Default(valueType);
+        var block = Expression.Block([valueVar], Expression.Condition(tryGetValueCall, valueVar, defaultValue));
+
+        return ConvertToSimpraType(block, false, context);
+    }
 }

tests/AltaSoft.Simpra.tests/Models/TestModel.cs

@@ -30,6 +30,9 @@ public class TestModel : BaseModel, ITransferModel
     public required Transfer? Transfer { get; set; }
     public required Customer Customer { get; set; }
     public required string Remittance { get; set; }
+    public Dictionary<string, string>? Countries { get; set; }
+
+    public Dictionary<string, Customer>? DictionaryOfObjects { get; set; }
 
     public ColorX ColorX { get; set; } = ColorX.Green;
     public ColorM ColorM { get; set; } = ColorM.Green;

tests/AltaSoft.Simpra.tests/SimpraExpressionTests.cs

@@ -4,6 +4,60 @@ namespace AltaSoft.Simpra.Tests;
 
 public class SimpraExpressionTests
 {
+
+    [Fact]
+    public void DictionaryIndexer_MissingKey_ReturnsDefaultValueForProperty()
+    {
+        const string expressionCode =
+            """
+            return DictionaryOfObjects['test'].Id
+            """;
+
+        var simpra = new Simpra();
+        var model = GetTestModel();
+        model.DictionaryOfObjects = new Dictionary<string, Customer> { { "Georgia", new Customer
+            {
+            Id = 1,
+            Status = 10
+        }} };
+
+        var result = simpra.Execute<int, TestModel, IFunctions>(model, new TestFunctions(), expressionCode);
+        Assert.Equal(0, result);
+
+    }
+
+    [Fact]
+    public void CallGetValueFromDictionaryWhenKeyDoesNotExist_ShouldReturnDefault()
+    {
+        const string expressionCode =
+            """
+            return Countries['test'] is 'Test'
+            """;
+
+        var simpra = new Simpra();
+        var model = GetTestModel();
+        model.Countries = new Dictionary<string, string> { { "Georgia", "Test" } };
+        var result = simpra.Execute<bool, TestModel, IFunctions>(model, new TestFunctions(), expressionCode);
+        Assert.False(result);
+
+    }
+
+    [Fact]
+    public void CallGetValueFromDictionaryWhenKeyExist_ShouldReturnValue()
+    {
+        const string expressionCode =
+            """
+            return Countries['Georgia'] is 'Test'
+            """;
+
+        var simpra = new Simpra();
+        var model = GetTestModel();
+        model.Countries = new Dictionary<string, string> { { "Georgia", "Test" } };
+        var result = simpra.Execute<bool, TestModel, IFunctions>(model, new TestFunctions(), expressionCode);
+        Assert.True(result);
+
+    }
+
     [Fact]
     public void CallInterfaceFunctionFromSimpra_ShouldReturnCorrectValue()
     {