Ytukyg

I have problem with rebuild for statement. I want to rebuild fragment code:

FOR(j, variable or integer, integer, > or < or <= or >=, - or +);

to

for(var j = variable or integer; j > or < or >= or <= 15; j-- or j++){}

For example FOR(j, k, >, -); -> for(var j = k; j > 15; j--){}. Besides I don't know how can separate elements on list <ArgumentListSyntax> to IdentifierNameSyntax or LiteralExpressionSyntax,when there will be two IdentifierNameSyntax or LiteralExpressionSyntax on list. So I don't know if my attempt to solve is correct.

public override SyntaxNode VisitInvocationExpression(InvocationExpressionSyntax node)

{

    // FOR(j, k, 10, >, -);



    if (node.Kind() == SyntaxKind.InvocationExpression)

    {

        InvocationExpressionSyntax invocationExpression = node;



        if (invocationExpression.GetFirstToken().ToString() == "FOR")

        {

            //List<ArgumentSyntax> argumentList = new List<ArgumentSyntax>();

            //List<IdentifierNameSyntax> test = new List<IdentifierNameSyntax>();

            var tmp = node.ChildNodes().OfType<ArgumentListSyntax>().FirstOrDefault();

            var tmp1 = tmp.ChildNodes().OfType<ArgumentSyntax>().FirstOrDefault();

            var tmp2 = tmp1.ChildNodes().OfType<IdentifierNameSyntax>().FirstOrDefault();

            var tmp3 = tmp.Arguments.ElementAt(1);

            var tmp4 = tmp3.ChildNodes().OfType<IdentifierNameSyntax>().FirstOrDefault();



            Console.WriteLine(tmp.Arguments.ElementAt(0));

            Console.WriteLine(tmp.Arguments);

            Console.WriteLine(tmp2.GetFirstToken());

            Console.WriteLine(tmp4);





            node = node.ReplaceNode(node, SyntaxFactory.ForStatement(SyntaxKind.ForKeyword, SyntaxKind.OpenParenToken,

                                    SyntaxFactory.VariableDeclaration(SyntaxFactory.IdentifierName("var"), )));

        }



    }

    return base.VisitInvocationExpression(node);

}

You don't need to separate elements in the ArgumentListSyntax to the literals or identifiers, because you actually have a formal structure of supporting invocation: FOR(j, variable|integer, variable|integer, >|<|<=|>=, -|+); so you assume that the second and third arguments may be literal or identifier, fourth is comparison element and so on. Therefore, you need to check that the input arguments satisfy these conditions and if are satisfiable do something useful:

...

// FOR(j, variable | integer, variable | integer, > | < | <= | >=, - | +);

if (node.Expression is IdentifierNameSyntax identifier && identifier.Identifier.ValueText.Equals("FOR"))

{

    var arguments = node.ArgumentList.Arguments;

    if (arguments.Count != 5) return node;

    var second = arguments[1].Expression;

    switch (second)

    {

        case IdentifierNameSyntax variable:

            // and some sepcific logic for identifier

            break;



        case LiteralExpressionSyntax literal when literal.Kind() == SyntaxKind.NumericLiteralExpression:

            // and some sepcific logic for literals and check, 

            // that the input literal is integer and is not rational value

            break;



        default:

            // current argument isn't literal or identifier you can not do anything

            return node;

    }



    // do the similar check for the other arguments

    // and replace node as you wish

    ...

}

If you still assume that your invocation can contains a couple of another nodes as arguments, for example for(j, "foo", "foo", method(), initValue, method(), 15, >, >, >, -, "foo") you will need to take arguments by different logic, for example take the first literal or identifier or something else:

...

    // the same code from the example above



    // here you can use an another logic to retrieve expression that you want

    var second = arguments.First(x => x.IsKind(SyntaxKind.NumericLiteralExpression) || x.IsKind(SyntaxKind.IdentifierName)).Expression; 

    switch (second)

    {

        // the same code from the example above

    }

    // the same code from the example above



    ...

}