public static IdentifierUsage GetUsage(SyntaxNode identifier)
{
if (identifier.Parent is MemberAccessExpressionSyntax memberAccess)
{
return(GetUsageForOperation(memberAccess.Parent));
}
if (identifier.Parent is ElementAccessExpressionSyntax elementAccess)
{
return(GetUsageForOperation(elementAccess.Parent));
}
IdentifierUsage GetUsageForOperation(SyntaxNode operationNode)
{
if (operationNode is AssignmentExpressionSyntax assignent)
{
switch (assignent.Kind())
{
case SyntaxKind.SimpleAssignmentExpression:
return(IdentifierUsage.WrittenTo());
case SyntaxKind.AddAssignmentExpression:
case SyntaxKind.SubtractAssignmentExpression:
//TODO: add more assignment expressions
return(IdentifierUsage.ReadFromAndWrittenTo());
}
}
else if (operationNode is PostfixUnaryExpressionSyntax postfix)
{
return(IdentifierUsage.ReadFromAndWrittenTo());
}
else if (operationNode is ArgumentSyntax argument)
{
var kind = argument.RefKindKeyword.Kind();
if (kind == SyntaxKind.RefKeyword)
{
return(IdentifierUsage.ReadFromAndWrittenTo());
}
if (kind == SyntaxKind.OutKeyword)
{
return(IdentifierUsage.WrittenTo());
}
}
return(IdentifierUsage.ReadFrom());
}
return(GetUsageForOperation(identifier.Parent));
}
public static TResult Match <TResult>(this IdentifierUsage instance, Func <IdentifierUsage.ReadFromAndWrittenToCase, TResult> readFromAndWrittenToCaseCase, Func <IdentifierUsage.WrittenToCase, TResult> writtenToCaseCase, Func <IdentifierUsage.ReadFromCase, TResult> readFromCaseCase)
{
if (instance is IdentifierUsage.ReadFromAndWrittenToCase readFromAndWrittenToCase)
{
return(readFromAndWrittenToCaseCase(readFromAndWrittenToCase));
}
if (instance is IdentifierUsage.WrittenToCase writtenToCase)
{
return(writtenToCaseCase(writtenToCase));
}
if (instance is IdentifierUsage.ReadFromCase readFromCase)
{
return(readFromCaseCase(readFromCase));
}
throw new Exception("Invalid IdentifierUsage type");
}
public static void Match(this IdentifierUsage instance, Action <IdentifierUsage.ReadFromAndWrittenToCase> readFromAndWrittenToCaseCase, Action <IdentifierUsage.WrittenToCase> writtenToCaseCase, Action <IdentifierUsage.ReadFromCase> readFromCaseCase)
{
if (instance is IdentifierUsage.ReadFromAndWrittenToCase readFromAndWrittenToCase)
{
readFromAndWrittenToCaseCase(readFromAndWrittenToCase);
return;
}
if (instance is IdentifierUsage.WrittenToCase writtenToCase)
{
writtenToCaseCase(writtenToCase);
return;
}
if (instance is IdentifierUsage.ReadFromCase readFromCase)
{
readFromCaseCase(readFromCase);
return;
}
throw new Exception("Invalid IdentifierUsage type");
}