static CodeAction CreateIndexerCodeAction(Document document, SyntaxNode root, ExpressionSyntax node, IPropertySymbol indexer, ElementAccessExpressionSyntax elementAccess)
{
var arguments = elementAccess.ArgumentList.Arguments;
var idx = arguments.IndexOf(node.Parent as ArgumentSyntax);
var name = indexer.Parameters[idx].Name;
return(CodeActionFactory.Create(
node.Span,
DiagnosticSeverity.Info,
string.Format("Add argument name '{0}'", name),
t2 =>
{
var newArguments = SyntaxFactory.SeparatedList <ArgumentSyntax>(
elementAccess.ArgumentList.Arguments.Take(idx).Concat(
elementAccess.ArgumentList.Arguments.Skip(idx).Select((arg, i) =>
{
if (arg.NameColon != null)
{
return arg;
}
return arg.WithNameColon(SyntaxFactory.NameColon(indexer.Parameters[i + idx].Name));
})
)
);
var newAttribute = elementAccess.WithArgumentList(elementAccess.ArgumentList.WithArguments(newArguments));
var newRoot = root.ReplaceNode((SyntaxNode)elementAccess, newAttribute).WithAdditionalAnnotations(Formatter.Annotation);
return Task.FromResult(document.WithSyntaxRoot(newRoot));
}
));
}
/// <summary>
/// Visits the given <see cref="ElementAccessExpressionSyntax"/>,
/// optionally replacing its index by
/// </summary>
public override SyntaxNode VisitElementAccessExpression(ElementAccessExpressionSyntax node)
{
var arguments = node.ArgumentList.Arguments;
for (int i = 0; i < arguments.Count; i++)
{
ArgumentSyntax index = node.ArgumentList.Arguments[i];
// Ensure the index is an int
IOperation operation = semanticModel.GetOperation(index.Expression);
if (operation?.Type?.MetadataName != typeof(int).Name)
{
continue;
}
// Replace expr[index] by expr[index - startAt]
ArgumentSyntax newIndex = SyntaxFactory.Argument(
SyntaxFactory.BinaryExpression(SyntaxKind.SubtractExpression, index.Expression, startAtSyntax)
);
arguments = arguments.RemoveAt(i)
.Insert(i, newIndex);
}
return(node.WithArgumentList(node.ArgumentList.WithArguments(arguments)));
}
public static ElementAccessExpressionSyntax WithExpressionsAsArgumentList(
this ElementAccessExpressionSyntax elementAccessExpression,
params ExpressionSyntax?[] expressions)
{
return(elementAccessExpression.WithArgumentList(
F.BracketedArgumentList(
F.SeparatedList(expressions.Where(e => e != null).Select(F.Argument)))));
}
public static ElementAccessExpressionSyntax WithArgumentList(this ElementAccessExpressionSyntax indexer, IEnumerable <ArgumentSyntax> arguments) => indexer.WithArgumentList(BracketedArgumentList(SeparatedList(arguments)));
