New visualizer

Src/AST/Myc.Ast.Binding.pas

@@ -810,14 +810,17 @@ begin
     condition := Accept(Node.Condition).AsIntf<IAstNode>;
     FNextIsTail := isContextTail;
     thenBranch := Accept(Node.ThenBranch).AsIntf<IAstNode>;
-    elseBranch := Accept(Node.ElseBranch).AsIntf<IAstNode>;
+    if Assigned(Node.ElseBranch) then
+        elseBranch := Accept(Node.ElseBranch).AsIntf<IAstNode>;
 
     conditionType := (condition as TAstNode).StaticType;
     if not TTypeRules.CanAssign(TTypes.Ordinal, conditionType) then
         raise ETypeException.CreateFmt('If condition must be Ordinal, but got %s', [conditionType.ToString]);
 
     thenType := (thenBranch as TAstNode).StaticType;
-    elseType := (elseBranch as TAstNode).StaticType;
+    elseType :=
+        if elseBranch <> nil then (elseBranch as TAstNode).StaticType
+        else TTypes.Void;
     resultType := TTypeRules.Promote(thenType, elseType);
 
     if (condition <> Node.Condition) or (thenBranch <> Node.ThenBranch) or (elseBranch <> Node.ElseBranch) then

Src/AST/Myc.Ast.Types.pas

@@ -477,6 +477,10 @@ begin
     if B.Kind = stUnknown then
         exit(A);
 
+    // all operations involving void result void
+    if (A.Kind = stVoid) or (B.Kind = stVoid) then
+        exit(TTypes.Void);
+
     // Standard Numeric promotion rule: Float wins
     if (A.Kind = stFloat) and (B.Kind = stFloat) then
         exit(TTypes.Float);

Src/AST/Myc.Ast.pas

@@ -922,13 +922,7 @@ end;
 
 class function TAst.IfExpr(const ACondition: IAstNode; const AThenBranch, AElseBranch: IAstNode): IIfExpressionNode;
 begin
-    Result :=
-        TIfExpressionNode.Create(
-            ACondition,
-            AThenBranch,
-            if AElseBranch = nil then TBlockExpressionNode.Create([]) as IAstNode
-            else AElseBranch
-        );
+    Result := TIfExpressionNode.Create(ACondition, AThenBranch, AElseBranch);
 end;
 
 class function TAst.Indexer(const ABase: IAstNode; const AIndex: IAstNode): IIndexerNode;