Develop Reference

How does Visual Studio syntax-highlight strings in the Regex constructor?

Hi fellow programmers and nerds!
When creating regular expressions Visual Studio, the IDE will highlight the string if it's preceded by a verbatim identifier (for example, #"Some string). This looks something like this:
(Notice the way the string is highlighted). Most of you will have seen this by now, I'm sure.
My problem: I am using a package acquired from NuGet which deals with regular expressions, and they have a function which takes in a regular expression string, however their function doesn't have the syntax highlighting.
As you can see, this just makes reading the Regex string just a pain. I mean, it's not all-too-important, but it would make a difference if we can just have that visually-helpful highlighting to reduce the time and effort one's brain uses trying to decipher the expression, especially in a case like mine where there will be quite a quantity of these expressions.
The question
So what I'm wanting to know is, is there a way to make a function highlight the string this way*, or is it just something that's hardwired into the IDE for the specific case of the Regex c-tor? Is there some sort of annotation which can be tacked onto the function to achieve this with minimal effort, or would it be necessary to use some sort of extension?
*I have wrapped the call to AddStyle() into one of my own functions anyway, and the string will be passed as a parameter, so if any modifications need to be made to achieve the syntax-highlight, they can be made to my function. Therefore the fact that the AddStyle() function is from an external library should be irrelevant.
If it's a lot of work then it's not worth my time, somebody else is welcome to develop an extension to solve this, but if there is a way...
Important distinction
Please bear in mind I am talking about Visual Studio, NOT Visual Studio Code.
Also, if there is a way to pull the original expression string from the Regex, I might do it that way, since performance isn't a huge concern here as this is a once-on-startup thing, however I would prefer not to do it that way. I don't actually need the Regex object.

According to https://devblogs.microsoft.com/dotnet/visual-studio-2019-net-productivity/#regex-language-support and https://www.meziantou.net/visual-studio-tips-and-tricks-regex-editing.htm you can mark the string with a special comment to get syntax highlighting:
// language=regex
var str = #"[A-Z]\d+;
or
MyMethod(/* language=regex */ #"[A-Z]\d+);
(the comment may contain more than just this language=regex part)
The first linked blog talks about a preview, but this feature is also present in the final product.

.NET 7 introduces the new [StringSyntax(...)] attribute, which is used in .NET 7 on more than 350 string, string[], and ReadOnlySpan<char> parameters, properties, and fields to highlight to an interested tool what kind of syntax is expected to be passed or set.
https://devblogs.microsoft.com/dotnet/regular-expression-improvements-in-dotnet-7/?WT_mc_id=dotnet-35129-website&hmsr=joyk.com&utm_source=joyk.com&utm_medium=referral
So for a method argument you should just use:
void MyMethod([StringSyntax(StringSyntaxAttribute.Regex)] string regex);
Here is a video demonstrating the feature: https://youtu.be/Y2YOaqSAJAQ

"redundant comma in array initializer" why it should be fixed

With ReSharper 6.0 I've received a new warning:
redundant comma in array initializer
for the case when I have a list of array initializer parameters with comma in the end.
What bad in that? Why I like "my" approach is that I often need to comment the latest value and don't want to bother with fixing those 'leading' commas:
private readonly string[] _tables
= new[]
{
"users",
"user_account",
"user_budget_type",
//"user_budget"
};
Please advise what is good in following that suggestion.
Thank you.

I agree that it shouldn't matter that there is a comma at the end, however, if you write your arrays like so, you don't have this problem.
private readonly string[] _tables
= new[]
{
"users"
,"user_account"
,"user_budget_type"
//,"user_budget"
};

The clue is in the text of the message:
redundant comma in array initializer
What does it mean by that? Well, your code:
private readonly string[] _tables
= new[]
{
"users",
"user_account",
"user_budget_type",
//"user_budget"
};
and the code with the inspection acted upon:
private readonly string[] _tables
= new[]
{
"users",
"user_account",
"user_budget_type"
//"user_budget"
};
are semantically equivalent. That is, the CIL produced in each case is identical - there is no difference in behaviour. So the comma changes nothing and is therefore redundant.
Now, as to your question:
What bad in that?
That's largely up to you. R# merely has this redundancy as an inspection, but it is you (through your acceptance of the default settings) that has it categorised as a warning.
If this construct is acceptable to your style, then by all means go ahead and change the Inspection Severity in R# options; but in general, the defaults for R# options are those that produce pretty close to the minimum amount of code necessary.

ReSharper is full of suggestions. Just like any other productivity tool, in the end it's up to you whether to act upon those suggestions.
For example, while the C# language allows a trailing comma or an empty control statement bodies (placing a ; for a loop body), or even typing duplicate ;; at the end of the statement. For all those things ReSharper will suggest you removing redundancies, because it's what it does - heuristically detects redundancies. If you know better, there are several ways you could "silence" ReSharper from suggesting it:
Temp. suppress the warning using special comments (choose the "Suppress inspection ... with comment" quickfix):
private readonly string[] _tables = new[]
{
"users",
"user_account",
// ReSharper disable RedundantCommaInArrayInitializer
"user_budget_type",
// ReSharper restore RedundantCommaInArrayInitializer
//"user_budget"
};
or
2. Suppress this warning completely by selecting "Inspection options for ...", and choosing "Do not show" in the options.
It's all about choice and personal preference - you can configure just about anything you want in the tool.

You can suppress that warning, Resharper is just saying that, just in case you care :)

#Budda, Unlike other have said, this redundant comma is eval!
In some browsers, for example IE8, this could cause the browser to misunderstand you and mis-create the object.
See this answer for example, where the trailing comma caused the Highcharts library to stop working.
Keeping your code clean is not only a matter of easier reading and debugging. Even if you see your code working with this comma, it doesn't mean that it will be working the same with all browsers.

Efficient means for parsing and replacing values in T-SQL

I have a lot of T-SQL queries I need to parse and replace certain values.
A query may look like this
SELECT dbo.udfTest(123,'Bob') as Foo
or alternatively
SELECT dbo.udfTest(123) as Foo
My task is to replace the number value with another given value but as I contemplate just rolling something up using the string class and doing substrings etc I start to run into lots of edge cases like this
SELECT dbo.udfTest ( 123 ) as Foo
or
SELECT [dbo].[udfTest]( 123 ) as Foo
or
SELECT [dbo].[udfTest]( 123 ) as Foo1, dbo.udfTest(123) as Foo2
Throw in any combination of whitespace, casing, brackets, nested parenthesis and you can imagine the number of variations I would have to cover...nasty.
Which brings me to wondering if there is a better way? RegEx may be a play but I figured I would toss it out to get some opinions.

You might be able to use the database features of Visual Studio. See API Reference for Database Features of Visual Studio, especially the Microsoft.Data.Schema.ScriptDom Namespace.
Also, a quick search for "parse mdx query" turned up several interesting hits. I'm pretty sure I once found a tool that could parse MDX queries, then use the parse tree to create a formatted version.
Perhaps the article Getting to the Crown Jewels will help. If nothing else, it may give you a hint about who to ask for help.

Matching multiple possible patterns says RegEx right off the bat. The RegEx will be ugly but it should get you where you want to go pretty easily.

If the end goal is to replace some set of numbers with a new set of numbers (basically a translation), wouldn't it be easier update your UDF to use a lookup table to map the old values to the new ones instead of trying to intercept every method call before it takes place? (Unless your examples have been greatly simplified in that they only show the same function being called each time, but in reality there's many that would have to be updated)

New code Lines in c# project is not executed

I`m a new guy to c# and I try to add a some code to a certain class in my c# project in order to remove some characters from a string. These lines of codes are not executed at run time and the debugger steps over it.So,
1) How to make the new lines added to an existing project execute?
2) Is there a property in Visual studio 2005 that prevents developers from changing existing code?
3) Is it some Property related to the c# project that specifies a privilege of code change?

you should try cleaning your project and rebuilding it, sometimes visual studio is stupid and does not rebuild all the assemblies. i find that this fixes this problem about 80% of the time (if it's not my code, that is)

1) Just rebuild entire solution
2) No, as far as I know
3) No, as far as I know

Check to make sure you are not returning the a value before the added lines. If you hit a return prior to getting to those new lines that will exit the function and your new code will never execute.

Since you mentioned string, are you assigning the output back to the variable?
E.g.
string aStr = " abcdefg ";
aStr = aStr.Trim();
If you only do aStr.Trim(), you won't see the "update".

"\0" has a particular meaning in C# strings. Are you actually trying to remove the null character, or are there literal backslashes and zeroes?
If you're trying to remove a backslash and then a zero, try this instead:
string sMailMsg = eMailMsg.ToString().Replace("\\0", string.Empty);

How to find the suspicious statement, like "Name = Name;" in C# by Regex?

My C# code has a lot of statement like "this.Name=...". In order to make my code neat, I let the text editor to replace all "this." to nothing. The code still worked. But later I fund it caused me a lot of new troubles for I wrote some statements like:
this.Name = Name; // the second Name is a parameter.
After the replacement, it became:
Name = Name;
Now, I met too much code. How to find the suspicious code like "Name = Name;" by Regex in VS 2010?
Thanks,
Ying

Why would you want to use Regex when you can simply compile the solution and look for the CS1717 warning:
Assignment made to same variable; did
you mean to assign something else?
Also note that in C# it is a good convention to have your parameters start with lowercase letter.

I would agree that Darin's approach is more robust and should be done first. However you might
have commented out sections of code which will be missed with this approach.
To try and find those you can use "Find in Files". In the Find box tick "Use regular expresssions" and enter {:i}:Wh*=:Wh*\1
:i C Style identifier ("tagged" expression by enclosing in braces)
:Wh* Zero or more white space chars
\1 back reference to tagged identifier found
This approach might bring back some false positives so you could try :Wh+{:i}:Wh*=:Wh*\1:Wh+ if there are too many but at the risk of missing some matches (e.g. where the closing comment mark is immediately after the assignment statement)

You could restore your last commit from your CVS, if you haven't changed too much since.
The problem with doing what you ask is that there might be other cases where "this" shouldn't have been replaced and you haven't seen the problem yet.