private async Task <Document> MakeForeachAsync(Document document, ForStatementSyntax forStatement, CancellationToken cancellationToken)
{
var semanticModel = await document.GetSemanticModelAsync(cancellationToken);
var forBlock = forStatement.Statement as BlockSyntax;
var condition = forStatement.Condition as BinaryExpressionSyntax;
var arrayAccessor = condition.Right as MemberAccessExpressionSyntax;
var arrayId = semanticModel.GetSymbolInfo(arrayAccessor.Expression).Symbol as ILocalSymbol;
var controlVarId = semanticModel.GetDeclaredSymbol(forStatement.Declaration.Variables.Single());
var arrayDeclarations = (from s in forBlock.Statements.OfType <LocalDeclarationStatementSyntax>()
where s.Declaration.Variables.Count == 1
let declaration = s.Declaration.Variables.First()
where declaration?.Initializer?.Value is ElementAccessExpressionSyntax
let init = (ElementAccessExpressionSyntax)declaration.Initializer.Value
let initSymbol = semanticModel.GetSymbolInfo(init.ArgumentList.Arguments.First().Expression).Symbol
where controlVarId.Equals(initSymbol)
let someArrayInit = semanticModel.GetSymbolInfo(init.Expression).Symbol as ILocalSymbol
where someArrayInit.Equals(arrayId)
select s).ToList();
var arrayDeclaration = arrayDeclarations.First();
var blockForFor = forBlock.RemoveNode(arrayDeclaration, SyntaxRemoveOptions.KeepLeadingTrivia);
var forEachStatement = SyntaxFactory.ForEachStatement(SyntaxFactory.ParseTypeName("var"), arrayDeclaration.Declaration.Variables.First().Identifier, arrayAccessor.Expression, blockForFor)
.WithLeadingTrivia(forStatement.GetLeadingTrivia())
.WithTrailingTrivia(forStatement.GetTrailingTrivia())
.WithAdditionalAnnotations(Formatter.Annotation);
var root = await document.GetSyntaxRootAsync();
var newRoot = root.ReplaceNode <SyntaxNode, SyntaxNode>(forStatement, forEachStatement);
var newDocument = document.WithSyntaxRoot(newRoot);
return(newDocument);
}
