Added ability to assign default value to a struct field / Added constructor struct init

Yail.Shared/Objects/StructObj.cs

@@ -1,4 +1,5 @@
 using Yail.Shared.Abstract;
+using Yail.Shared.Helpers;
 
 namespace Yail.Shared.Objects;
 
@@ -24,6 +25,19 @@ public void Set(string variableName, ValueObj value)
         Value = list;
     }
 
+    public void Update(string variableName, ValueObj valueObj)
+    {
+        var fields = Get();
+
+        if (!fields.TryGetValue(variableName, out var prevValue))
+            ExceptionHelper.PrintError($"Variable '{variableName}' is not defined in struct '{Name}'");
+
+        if (!prevValue.ValueEquals(valueObj))
+            ExceptionHelper.PrintError($"Data types must be equal.");
+
+        fields[variableName] = valueObj;
+    }
+
     public Dictionary<string, ValueObj> Get()
     {
         return Value as Dictionary<string, ValueObj>;

Yail.Shared/ValueObj.cs

@@ -77,4 +77,13 @@ public virtual void Print(bool newLine = false)
 
         Console.Write(val);
     }
+
+    public bool ValueEquals(object? obj)
+    {
+        if (obj is ValueObj other)
+        {
+            return Value.GetType() == other.Value.GetType() && DataType == other.DataType;
+        }
+        return false;
+    }
 }

Yail.Tests/StructTests.cs

@@ -177,4 +177,98 @@ pub struct Point {
             Assert.Pass();
         }
     }
+
+    [Test]
+    public void CreateStructWithCtor()
+    {
+        var code = @"
+                    package main
+
+                    pub struct Point {
+                        var x i32;
+                        var z i32;
+                        var y i32;
+                    }
+
+                    var p = new Point() {
+                        y = 2;
+                    };
+                    print(p.y);
+                ";
+
+        var actual = RunCode(code);
+
+        Assert.That(actual, Is.EqualTo("2"));
+    }
+
+    [Test]
+    public void CreateStructWithCtorAndAssignValue()
+    {
+        var code = @"
+                    package main
+
+                    pub struct Point {
+                        var x i32;
+                        var z i32;
+                        var y i32;
+                    }
+
+                    var p = new Point() {
+                        y = 2;
+                    };
+                    println(p.y);
+                    p.y = 3;
+                    print(p.y);
+                ";
+
+        var actual = RunCode(code);
+
+        Assert.That(actual, Is.EqualTo("2\n3"));
+    }
+
+    [Test]
+    public void CreateStructWithDefaultValue()
+    {
+        var code = @"
+                    package main
+
+                    pub struct Point {
+                        var x i32;
+                        var z i32;
+                        var y i32 = 3;
+                    }
+
+                    var p = new Point();
+
+                    print(p.y);
+                ";
+
+        var actual = RunCode(code);
+
+        Assert.That(actual, Is.EqualTo("3"));
+    }
+
+    [Test]
+    public void CreateStructWithDefaultValue_ConstructorAssign()
+    {
+        var code = @"
+                    package main
+
+                    pub struct Point {
+                        var x i32;
+                        var z i32;
+                        var y i32 = 3;
+                    }
+
+                    var p = new Point() {
+                        y = 5;
+                    }; 
+
+                    print(p.y);
+                ";
+
+        var actual = RunCode(code);
+
+        Assert.That(actual, Is.EqualTo("5"));
+    }
 }

Yail/ExpressionsVisitor.cs

@@ -51,11 +51,18 @@ public sealed class ExpressionsVisitor : ExpressionsBaseVisitor<ValueObj?>
             return null;
         }
 
+        if (_currentStruct is not null)
+        {
+            if (!_instances.TryGetValue(_currentStruct, out var currStruct))
+                ExceptionHelper.PrintError($"Struct '{_currentStruct}' is not defined.");
+
+            (currStruct as StructObj)!.Update(variableName, value);
+            return null;
+        }
+
         if (!_variables.TryGetValue(variableName, out var prevVal))
         {
-            Console.ForegroundColor = ConsoleColor.Red;
-            Console.Error.WriteLine($"Variable '${variableName}' is not defined.");
-            Environment.Exit(1);
+            ExceptionHelper.PrintError($"Variable '${variableName}' is not defined.");
         }
 
         if (prevVal is IAccessible accessible)
@@ -1027,7 +1034,18 @@ public override ValueObj VisitStructBlock(ExpressionsParser.StructBlockContext c
             var varName = structLine.variableDefine().IDENTIFIER().GetText();
             var dataType = structLine.variableDefine().DATA_TYPES().GetText().ToDataType();
 
-            structObj.Set(varName, new ValueObj(dataType));
+            var expr = structLine.variableDefine().expression();
+
+            if (expr is not null)
+            {
+                var defaultVal = Visit(expr);
+
+                structObj.Set(varName, defaultVal);
+            }
+            else
+            {
+                structObj.Set(varName, new ValueObj(dataType));
+            }
         }
 
         if (!_instances.TryAdd(structObj.Name, structObj))
@@ -1038,6 +1056,7 @@ public override ValueObj VisitStructBlock(ExpressionsParser.StructBlockContext c
         return structObj;
     }
 
+    private string? _currentStruct;
     public override ValueObj? VisitInstanceCreateExpr(ExpressionsParser.InstanceCreateExprContext context)
     {
         var instanceName = string.Empty;
@@ -1052,7 +1071,13 @@ public override ValueObj VisitStructBlock(ExpressionsParser.StructBlockContext c
         {
             instanceName = context.instanceCreate().IDENTIFIER(0).GetText();
         }
-
+
+        if (context.instanceCreate().instanceBody() is not null)
+        {
+            _currentStruct = $"{packageName}::{instanceName}";
+            Visit(context.instanceCreate().instanceBody());
+            _currentStruct = null;
+        }
 
         var valueObj = _instances[$"{packageName}::{instanceName}"];
 

Yail/Grammar/Expressions.g4

@@ -24,6 +24,10 @@ block: '{' line* '}';
 structBody: '{' structLine* '}';
 structLine: variableDefine ';'; 
 
+// structs new calling 'new'
+instanceBody: '{' instanceLine* '}';
+instanceLine: assignment ';'; 
+
 directive: '#' 'use' USE_IDENTIFIERS;
 
 multiplyOp: '*' | '/' | '%';
@@ -67,7 +71,7 @@ packageDeclaration: 'package' IDENTIFIER;
 usingDirective: 'using' IDENTIFIER;
 
 variableDeclaration: 'var' IDENTIFIER '=' REFERENCE? expression;
-variableDefine: 'var' IDENTIFIER DATA_TYPES;
+variableDefine: 'var' IDENTIFIER DATA_TYPES ('=' expression)?;
 functionDeclaration: (accessLevels)? 'funky' IDENTIFIER '(' (parameterList)? ')' DATA_TYPES block;
 
 parameterList: parameter (',' parameter)*;
@@ -97,6 +101,6 @@ foreachBlock: FOREACH '(' 'var' IDENTIFIER 'in' expression ')' block;
 
 structBlock: accessLevels? 'struct' IDENTIFIER structBody;
 
-instanceCreate: 'new' (IDENTIFIER '::')? IDENTIFIER '(' (expression (',' expression)*)? ')';
+instanceCreate: 'new' (IDENTIFIER '::')? IDENTIFIER '(' (expression (',' expression)*)? ')' instanceBody?;
 instancePropAssign: IDENTIFIER '.' IDENTIFIER '=' expression;
 instancePropCall: IDENTIFIER '.' IDENTIFIER;