C# generated code fails with Unrecognized escape sequence \\N.

[PaulEPetersen]

Bug Description

When generating c# code using the \N works in the https://regex101.com/ website but putting the generated code into c# doesnt work

System.Text.RegularExpressions.RegexParseException HResult=0x80070057 Message=Invalid pattern '(?\d{2}\/\d{2}\/\d{4})\,\s(?\d{2}:\d{2})\s-\s(?.\n{0,1}(((?!\d\d\/\d\d\/\d\d)\N\n){0,}))' at offset 101. Unrecognized escape sequence \N. Source=System.Text.RegularExpressions StackTrace: at System.Text.RegularExpressions.RegexParser.ScanCharEscape() at System.Text.RegularExpressions.RegexParser.ScanBasicBackslash(Boolean scanOnly) at System.Text.RegularExpressions.RegexParser.ScanBackslash(Boolean scanOnly) at System.Text.RegularExpressions.RegexParser.CountCaptures() at System.Text.RegularExpressions.RegexParser.Parse(String pattern, RegexOptions options, CultureInfo culture) at System.Text.RegularExpressions.Regex.Init(String pattern, RegexOptions options, TimeSpan matchTimeout, CultureInfo culture) at System.Text.RegularExpressions.Regex..ctor(String pattern, RegexOptions options, TimeSpan matchTimeout, CultureInfo culture) at System.Text.RegularExpressions.RegexCache.GetOrAdd(String pattern, RegexOptions options, TimeSpan matchTimeout) at System.Text.RegularExpressions.Regex.Matches(String input, String pattern, RegexOptions options) at TestProject.Example.aMain2() in ......cs:line 419 at TestProject......DecomposeText() in ......cs:line 21

Reproduction steps

generate c# regex using https://regex101.com/ using \N

Expected Outcome

the regex works in C#

Browser

N/A

OS

Windows 11

[working-name]

Did .net recently implement N? Otherwise you may be writing your regex in PCRE expecting it to work in .net which unfortunately won't work 100%. Some features exist in either of the engines that the other doesn't have.

[PaulPetersenAtTheAA]

I don't know, I would guess. Net hasn't implemented hence the problem. The generator should only generate working code IMHO. Not sure what pcre is

[working-name]

It generates example code for a specific language you choose, but it doesn't interpret and translate regex from one flavor to another - that would be a rather huge undertaking and at times impossible because there isn't always an alternate way of doing something.

Generally if you select the target flavor (.net) while you're developing the regex you're going to get feedback on things not implemented - although it could also be the site not running the latest and greatest .net build for example. Either way, it's probably less headache than finding out like this.

Hope this helps 😃