Doxygen will not generate class information for a C# class that contains certain string combinations

[gvsoft3750]

Doxygen fails to generate any class information for a class if the source file contains certain string combinations:

namespace MyNamespace
{
    public class MyClass
    {
        public string MyMethod()
        {
            return $"'{"''"}'"; // fails (class information is NOT generated)
        }
    }
}

When no class information is generated:

Here is what is expected:

Replacing the above return statement with the following gives the results as described in the comment:

return $"'{"''"}'"; // fails (class information is NOT generated)
return $"'{"'"}'"; // fails (class information is NOT generated)
return $"'{""}'"; // okay (class information is generated)
return $"'{"''"}"; // okay (class information is generated)
return $"'{""}'"; // okay (class information is generated)

The original code where I discovered this issue looked like this:

returnValue = $"'{value.Replace("'", "''")}'";

I am using Doxygen v1.9.5 (obtained via download), on Windows 10, 64-bit

I was able to work around the problem in my original code by doing this:

string replaced = value.Replace("'", "''");
returnValue = $"'{replaced}'";

Dennis Jones

[albert-github]

How would the resulting return value look like?

[gvsoft3750]

The statement is intended to take a C-style string and convert it into a form that can be stored in SQL.  That is, it replaces any embedded single-quotes by doubling them, and then wraps the entire string in single-quotes.  For example, a possible result might be: ``` 'Table ''Item''  is empty' ``` Hope that is clear. Dennis Sent from my T-Mobile 4G LTE Device -------- Original message --------From: albert-github ***@***.***> Date: 12/22/22 1:34 AM (GMT-08:00) To: doxygen/doxygen ***@***.***> Cc: gvsoft3750 ***@***.***>, Author ***@***.***> Subject: Re: [doxygen/doxygen] Doxygen will not generate class information for a C# class that contains certain string combinations (Issue #9736) How would the resulting return value look like? —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you authored the thread.Message ID: ***@***.***>

[albert-github]

It looks like we have to do here with so called interpolated strings in C# which have a bit of a (in C-terms) peculiar form as when we look at:

$"'{"''"}'"

As far as I understand it running through the string:

• the $" starts the interpolated string
• the ' is a regular character
• the { starts the part to be "interpolated"
• the "''" is a string in to be "interpolated"
• the } ends the part to be "interpolated"
• the ' is a regular character
• the " ends the interpolated string

Is this a good summary?

[gvsoft3750]

You are correct. This is C#, and it is an example of string interpolation.  Your summary is reasonable.  This is a contrived example, however, as there would never be any reason to put two single-quote characters inside the interpolated section (within the curly braces).  I did include the real code in my original post.DennisSent from my T-Mobile 4G LTE Device -------- Original message --------From: albert-github ***@***.***> Date: 12/22/22 3:42 AM (GMT-08:00) To: doxygen/doxygen ***@***.***> Cc: gvsoft3750 ***@***.***>, Author ***@***.***> Subject: Re: [doxygen/doxygen] Doxygen will not generate class information for a C# class that contains certain string combinations (Issue #9736) It looks like we have to do here with so called interpolated strings in C# which have a bit of a (in C-terms) peculiar form as when we look at: $"'{"''"}'" As far as I understand it running through the string: the $" starts the interpolated string the ' is a regular character the { starts the part to be "interpolated" the "''" is a string in to be "interpolated" the } ends the part to be "interpolated" the ' is a regular character the " ends the interpolated string Is this a good summary? —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you authored the thread.Message ID: ***@***.***>

[albert-github]

Looks like after numerous years a new version of the C# Language Definition (Standard ECMA-334 6th Edition i.e. https://www.ecma-international.org/wp-content/uploads/ECMA-334_6th_edition_june_2022.pdf) has been released.

[gvsoft3750]

Interpolated strings are not new to C#.  They've been in the language for several years. DennisSent from my T-Mobile 4G LTE Device -------- Original message --------From: albert-github ***@***.***> Date: 12/22/22 3:59 AM (GMT-08:00) To: doxygen/doxygen ***@***.***> Cc: gvsoft3750 ***@***.***>, Author ***@***.***> Subject: Re: [doxygen/doxygen] Doxygen will not generate class information for a C# class that contains certain string combinations (Issue #9736) Looks like after numerous years a new version of the C# Language Definition (Standard ECMA-334 6th Edition i.e. https://www.ecma-international.org/wp-content/uploads/ECMA-334_6th_edition_june_2022.pdf) has been released. —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you authored the thread.Message ID: ***@***.***>

[albert-github]

I've just pushed a proposed patch, pull request #9738