public SyntaxNode InsertVariables(SyntaxNode root, SemanticModel model)
{
var patterns = root
.DescendantNodes()
.OfType <IsPatternExpressionSyntax>();
var updatedStatements = new Dictionary <SyntaxNode, List <LocalDeclarationStatementSyntax> >();
foreach (var pattern in patterns)
{
try
{
SyntaxNode lambdaExpr = pattern.Ancestors().OfType <LambdaExpressionSyntax>().FirstOrDefault();
SyntaxNode beforeStatement = pattern.Ancestors().OfType <StatementSyntax>().FirstOrDefault();
if (pattern.Pattern is DeclarationPatternSyntax declarationPattern)
{
if (lambdaExpr != null && !SyntaxHelper.IsChildOf(beforeStatement, lambdaExpr))
{
if (lambdaExpr is ParenthesizedLambdaExpressionSyntax pl && !(pl.Body is BlockSyntax))
{
beforeStatement = lambdaExpr;
}
else if (lambdaExpr is SimpleLambdaExpressionSyntax sl && !(sl.Body is BlockSyntax))
{
beforeStatement = lambdaExpr;
}
}
if (beforeStatement != null)
{
var designation = declarationPattern.Designation as SingleVariableDesignationSyntax;
if (designation != null)
{
if (!typesInfo.Keys.Contains(declarationPattern.Type.ToString()))
{
var ti = model.GetTypeInfo(declarationPattern.Type);
var isValueType = ti.Type != null ? ti.Type.IsValueType : false;
typesInfo[declarationPattern.Type.ToString()] = isValueType;
}
var locals = updatedStatements.ContainsKey(beforeStatement) ? updatedStatements[beforeStatement] : new List <LocalDeclarationStatementSyntax>();
var varDecl = SyntaxFactory.VariableDeclaration(declarationPattern.Type).WithVariables(SyntaxFactory.SingletonSeparatedList <VariableDeclaratorSyntax>(
SyntaxFactory.VariableDeclarator(SyntaxFactory.Identifier(designation.Identifier.ValueText))
));
locals.Add(SyntaxFactory.LocalDeclarationStatement(varDecl).WithTrailingTrivia(SyntaxFactory.Whitespace("\n")).NormalizeWhitespace());
updatedStatements[beforeStatement] = locals;
}
}
}
}
