Implementation FOR statement

[andmattia]

I try to implement the Loop Expression for "FOR statement". Below the rule and the code
using System; using NRules.RuleSharp.IntegrationTests.TestAssets; rule ""Metadata Rule 1"" description ""Rule with description and priority"" priority 10 when var fact = TestFact1(); then var tfi =Convert.ToInt32(0); for(var a=0;a<5;a=a+1) tfi = tfi+1; ";
I change the code in ExpressionParser.cs

 public override Expression VisitForStatement(ForStatementContext context)
        {
            var loopVar = Expression.Parameter(typeof(string), "loopVar");
            var initValue = Visit(context.for_initializer());
            var condition = Visit(context.expression());
            var increment = Visit(context.for_iterator());

            var loopContent = Visit(context.embedded_statement());
            var initAssign = Expression.Assign(loopVar, initValue);

            var breakLabel = Expression.Label("LoopBreak");

            var loop = Expression.Block(new[] { loopVar },
                initAssign,
                Expression.Loop(
                    Expression.IfThenElse(
                        condition,
                        Expression.Block(
                            loopContent,
                            increment
                        ),
                        Expression.Break(breakLabel)
                    ),
                    breakLabel)
            );
            return loop;
        }

I try to debug using unit test class and the first step work well (initValue return 0) but when I call the second step (var condition = Visit(context.expression());) I catch an exception

The complete stack trace is
in NRules.RuleSharp.PrimaryExpressionBuilder.GetExpression() in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\PrimaryExpressionBuilder.cs:riga 29 in NRules.RuleSharp.ExpressionParser.VisitPrimary_expression(Primary_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 249 in NRules.RuleSharp.Parser.RuleSharpParser.Primary_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 2661 in NRules.RuleSharp.ExpressionParser.VisitUnary_expression(Unary_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 262 in NRules.RuleSharp.Parser.RuleSharpParser.Unary_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 2503 in NRules.RuleSharp.ExpressionParser.VisitMultiplicative_expression(Multiplicative_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 490 in NRules.RuleSharp.Parser.RuleSharpParser.Multiplicative_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 2419 in NRules.RuleSharp.ExpressionParser.VisitAdditive_expression(Additive_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 517 in NRules.RuleSharp.Parser.RuleSharpParser.Additive_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 2342 in Antlr4.Runtime.Tree.AbstractParseTreeVisitor`1.VisitChildren(IRuleNode node) in NRules.RuleSharp.Parser.RuleSharpParserBaseVisitor`1.VisitShift_expression(Shift_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParserBaseVisitor.cs:riga 897 in NRules.RuleSharp.Parser.RuleSharpParser.Shift_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 2262 in NRules.RuleSharp.ExpressionParser.VisitRelational_expression(Relational_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 381 in NRules.RuleSharp.Parser.RuleSharpParser.Relational_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 2159 in NRules.RuleSharp.ExpressionParser.VisitEquality_expression(Equality_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 467 in NRules.RuleSharp.Parser.RuleSharpParser.Equality_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 2065 in NRules.RuleSharp.ExpressionParser.VisitAnd_expression(And_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 456 in NRules.RuleSharp.Parser.RuleSharpParser.And_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 1992 in NRules.RuleSharp.ExpressionParser.VisitExclusive_or_expression(Exclusive_or_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 445 in NRules.RuleSharp.Parser.RuleSharpParser.Exclusive_or_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 1929 in NRules.RuleSharp.ExpressionParser.VisitInclusive_or_expression(Inclusive_or_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 434 in NRules.RuleSharp.Parser.RuleSharpParser.Inclusive_or_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 1866 in NRules.RuleSharp.ExpressionParser.VisitConditional_and_expression(Conditional_and_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 423 in NRules.RuleSharp.Parser.RuleSharpParser.Conditional_and_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 1803 in NRules.RuleSharp.ExpressionParser.VisitConditional_or_expression(Conditional_or_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 412 in NRules.RuleSharp.Parser.RuleSharpParser.Conditional_or_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 1736 in NRules.RuleSharp.ExpressionParser.VisitNull_coalescing_expression(Null_coalescing_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 370 in NRules.RuleSharp.Parser.RuleSharpParser.Null_coalescing_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 1673 in NRules.RuleSharp.ExpressionParser.VisitConditional_expression(Conditional_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 358 in NRules.RuleSharp.Parser.RuleSharpParser.Conditional_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 1612 in Antlr4.Runtime.Tree.AbstractParseTreeVisitor`1.VisitChildren(IRuleNode node) in NRules.RuleSharp.Parser.RuleSharpParserBaseVisitor`1.VisitNon_assignment_expression(Non_assignment_expressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParserBaseVisitor.cs:riga 765 in NRules.RuleSharp.Parser.RuleSharpParser.Non_assignment_expressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 1375 in Antlr4.Runtime.Tree.AbstractParseTreeVisitor`1.VisitChildren(IRuleNode node) in NRules.RuleSharp.Parser.RuleSharpParserBaseVisitor`1.VisitExpression(ExpressionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParserBaseVisitor.cs:riga 754 in NRules.RuleSharp.Parser.RuleSharpParser.ExpressionContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 1311 in NRules.RuleSharp.ExpressionParser.VisitForStatement(ForStatementContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 322 in NRules.RuleSharp.Parser.RuleSharpParser.ForStatementContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 6685 in Antlr4.Runtime.Tree.AbstractParseTreeVisitor`1.VisitChildren(IRuleNode node) in NRules.RuleSharp.Parser.RuleSharpParserBaseVisitor`1.VisitEmbedded_statement(Embedded_statementContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParserBaseVisitor.cs:riga 1370 in NRules.RuleSharp.Parser.RuleSharpParser.Embedded_statementContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 6415 in Antlr4.Runtime.Tree.AbstractParseTreeVisitor`1.VisitChildren(IRuleNode node) in NRules.RuleSharp.Parser.RuleSharpParserBaseVisitor`1.VisitEmbeddedStatement(EmbeddedStatementContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParserBaseVisitor.cs:riga 311 in NRules.RuleSharp.ExpressionParser.VisitEmbeddedStatement(EmbeddedStatementContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 24 in NRules.RuleSharp.Parser.RuleSharpParser.EmbeddedStatementContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 6216 in NRules.RuleSharp.ExpressionParser.VisitStatement_list(Statement_listContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\ExpressionParser.cs:riga 57 in NRules.RuleSharp.Parser.RuleSharpParser.Statement_listContext.Accept[TResult](IParseTreeVisitor`1 visitor) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 8198 in NRules.RuleSharp.RuleParserListener.ParseActionExpression(Rule_actionContext context, IEnumerable`1 parameters) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\RuleParserListener.cs:riga 151 in NRules.RuleSharp.RuleParserListener.EnterRule_action(Rule_actionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\RuleParserListener.cs:riga 141 in NRules.RuleSharp.Parser.RuleSharpParser.Rule_actionContext.EnterRule(IParseTreeListener listener) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 18631 in Antlr4.Runtime.Tree.ParseTreeWalker.Walk(IParseTreeListener listener, IParseTree t) in NRules.RuleSharp.RuleSharpParserListener.EnterRule_definition(Rule_definitionContext context) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\RuleSharpParserListener.cs:riga 42 in NRules.RuleSharp.Parser.RuleSharpParser.Rule_definitionContext.EnterRule(IParseTreeListener listener) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\obj\Debug\net45\RuleSharpParser.cs:riga 18691 in Antlr4.Runtime.Tree.ParseTreeWalker.Walk(IParseTreeListener listener, IParseTree t) in NRules.RuleSharp.RuleRepository.Load(AntlrInputStream input) in C:\Repos\andmattia\NRules.Language\src\NRules.RuleSharp\NRules.RuleSharp\RuleRepository.cs:riga 148

I don't know if is not the correct way to build that rule but I adopt similar step used for IF. Any idea? Or if exist some document that can I use to understand how to identify / fix this issue