static SeparatedSyntaxList <ExpressionSyntax> ToggleIncrement(ForStatementSyntax @for)
{
var incrementor = (PostfixUnaryExpressionSyntax)@for.Incrementors[0];
var newIncrementor = SyntaxFactory.PostfixUnaryExpression(
InvertForAnalyzer.IsPostIncrement(incrementor) ? SyntaxKind.PostDecrementExpression : SyntaxKind.PostIncrementExpression,
incrementor.Operand);
return(new SeparatedSyntaxList <ExpressionSyntax>().Add(newIncrementor));
}
private async static Task <Document> InvertForAsync(Document document, Diagnostic diagnostic, CancellationToken cancellationToken)
{
var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
var diagnosticSpan = diagnostic.Location.SourceSpan;
var @for = root.FindToken(diagnosticSpan.Start).Parent.AncestorsAndSelf().OfType <ForStatementSyntax>().First();
if (InvertForAnalyzer.IsPostIncrement(@for.Incrementors[0]))
{
return(await ConvertToDecrementingCounterForLoopAsync(document, @for, cancellationToken));
}
return(await ConvertToIncrementingCounterForLoopAsync(document, @for, cancellationToken));
}