Copy Every thing after a regex is matched - c#

i have to create a function GetSourceCodeOfClass("ClassName",FilePath) this function will be used more than 10000 times to get Srouce code from c# Files, and from every source file i have to extract the source code of a complete class i.e
" Class someName { every thing in the body including sinature} "
Now this is simple, if a single file contains a single class but there will be many source files that will contain more than two classes in them , further more the bigger problem is there maybe nested classes inside a single class.
i want following thing :-
i want to extract the complete source of a given Class
if file contains more than two classes then i want to extract only the source code of specified class.
if file contains more than one class and my specified class have nested classes in it then i want to capture myClasses's source as well as all nested classes.
i have an algorithm in mid that is:
1-open file
2-match regex (C# classes signature ) - parameterized
#"(public|private|internal|protected|inline)?[\t ]*(static)?[\t
]class[\t ]" + sOurClassName + #"(([\t ][:][\t ]([a-zA-z]+(([
])[,]([ ])\w+))+))?\s[\n\r\t\s]?{"
3- If Regex is matched in the source file
4 Start copying at that point until the same regex is matched again but without parameters
regex is:
#" (public|private|internal|protected)?[\t ]*(static)?[\t ]class[\t
]\w+(([\t ][:][\t ]([a-zA-z]+(([ ])[,]([
])\w+))+))?\s[\n\r\t\s]?{"
(this is where i have no clue and i am stuck. I want to copy every thing after first matched to the second matched or after first match till the end )
copying nested classes is still an issue and i am still thinking about it if some one have an idea , can help me in this too.
Note- match.groups[0] or match.groups[1] this will only copy the signature but i want the complete source of the class thats why i am doing this way . ..
BTW i am using C#

I agree with Nathan's sentiment that you would be better using an existing C#-aware parser. Trying to write a regex for the task is a lot of work, and you are unlikely to get it right on the first try. It may work on your first example code, or even the first few, but eventually you'll find some code that's slightly different than what you expected and the regex will fail to catch something important.
That said, if you are comfortable with that limitation and risk, the general technique you are asking about (if I understand correctly…the question isn't entirely clear) is common enough, and worth understanding if you expect to use regex a lot. The key points to understand are that with a Match object, you can call the NextMatch() method to obtain the next match in the next, and that when calling the Regex.Match() method, you can pass the start and length of a substring you want to check, and it will limit its processing to that substring.
You can use the latter point to switch from one regex to another mid-parse.
In your scenario, I understand it to be that you want to run a regex containing the specific class name, to find that particular class in the file, and then to search the text after the initial match for any subsequent class in the file. If the second search finds something, you want to only return the text from the start of the first match to the start of the second match. If the second search finds nothing, you want to return the text from the start of the first match to the end of the whole file.
If that's correct, then something like this should work:
string ExtractClass(string fileContents, Regex classRegex, Regex nonClassRegex)
{
Match match1 = classRegex.Match(fileContents);
if (!match1.Success)
{
return null;
}
Match match2 = nonClassRegex.Match(fileContents, match1.Index + match1.Length);
if (!match2.Success)
{
return fileContents.Substring(match1.Index);
}
return fileContents.Substring(match1.Index, match2.Index - match1.Index);
}
I should note that between two class declarations, or between the end of a lone class declaration and the actual end of the file there can easily be other non-white-space text that isn't part of the class declaration. I assume you have a plan for dealing with that.
If the above doesn't address your need, you should examine your question closely, and edit it both for length and clarity.

Related

Regular Expression For File Name in C#

I am trying to find a regular expression to parse two sections out of the file name for the .resx files in my project. There is one main file called "UiText.resx" and then many translation .resx files with convention "UiText.ja-JP.resx". I need both the "UiText" and the "ja-JP" out of the latter string, as we do have other resx files that don't have to be for UiText (e.g. I have some files named "ExceptionText.resx").
The pattern I'm using right now (which works, it just requires a little extra coding after) is "(?<=\.)((.*?)(?=\.resx))". For the example above, "UiText.ja-JP.resx" gets me a match set in C# of "UiText.", "ja-JP.", "ja-JP.", ".resx"
Of course I am able to just take the first occurrence of "ja-JP." and "UiText." from this set and massage it to what I want, but I'd rather just have a cleaner "UiText" "ja-JP" and be done with it.
I figure I'll probably have to have at least two different patterns for this, so that is OK. Thank you in advance!
Since UiText seems to be constant you can use this regex to extract just js-JP into $1:
^UiText\.(.+?)\.resx$
https://regex101.com/r/XKvwHA/1/
If I'm understanding your needs correctly, then the main reason you need "UiText" is not because you have any value for the term itself, but rather because you need to filter your files. The real term you need to play around with is "ja-JP", which changes for the files you need.
If I'm correct, try this regex:
(?<=UiText\.).+(?=\.resx)
Used in C# as follows:
var fileName = "UiText.ja-JP.resx";
var result = new Regex(#"(?<=^UiText\.).+(?=\.resx$)").Match(fileName).Value;
A little explanation:
(?<=^UiText\.) Start of string must begin exactly with "UiText."
.+ Any number of characters (but at least one)
(?=\.resx$) End of string must end with ".resx"
Any file that doesn't meet your criteria will return an empty string for 'result'.

Replace beginning and end of string with unique midle?

I have lots of code like below:
PlusEnvironment.EnumToBool(Row["block_friends"].ToString())
I need to convert them to something like this.
Row["block_friends"].ToString() == "1"
The value that gets passed to EnumToBool is always unique, meaning there is no guarantee that itll be passed by a row, it could be passed by a variable, or even a method that returns a string.
I've tried doing this with regex, but its sort of sketchy and doesn't work 100%.
PlusEnvironment\.EnumToBool\((.*)\)
I need to do this in Visual Studio's find and replace. I'm using VS 17.
If you had a few places where PlusEnvironment.EnumToBool() was called, I would have done the same thing that #IanMercer suggested: just replace PlusEnvironment.EnumToBool( with empty string and the fix all the syntax errors.
#IanMercer has also given you a link to super cool, advanced regex usage that will help you.
But if you are skeptical about using such a complex regex on hundreds of files, here is what I would have done:
Define my own PlusEnvironment class with EnumToBool functionality in my own namespace. And then just replace the using Plus; line with using <my own namespace>; in those hundreds of files. That way my changes will be limited to only the using... line, 1 line per file, and it will be simple find and replace, no regex needed.
(Note: I'm assuming that you don't want to use PlusEnvironment, or the complete library and hence you want to do this type of replacement.)
in Find and Replace Window:
Find:
PlusEnvironment\.EnumToBool\((.*))
Replace:
$1 == "1"
Make sure "Use Regular Expressions" is selected

Is there a better way to check if an entire string was matched? [duplicate]

This question already has answers here:
Match exact string
(3 answers)
Closed 3 years ago.
I'm parsing a text file line by line and for each line I have a special regex. However in one case a pattern is matching two lines. One that is a correct match and another line only partialy because a couple of values are optional.
Invalid match:
BNE1010/1000 HKG1955/2005 7/PLD/CLD/YLD
matches patial string (shouln't match this at all):
BNE1010/1000
Correct match (matches the entire string):
RG878A/21AUG15 GIG/BOG 1/RG/AV 3/AV 4/AV 5/RG 6/AV081C/22 7/CDC/YD 9/TP
The regex for this is quite long and contains several optionl groups:
^(?<FlightDesignator>([A-Z0-9]{2}[A-Z]?)([0-9]{3,4}))(?<OperationalSuffix>[A-Z])?(?<FlightIdentifierDate>\/(\d{2})([A-Z]{3})?(\d{2})?)?(\s(?<FlightLegsChangeIdentifier>(\/?[A-Z]{3})+)(?=(\s|$)))?(\s1(?<JointOperationAirlineDesignators>(\/.{2}[A-Z]?)+))?(\s3\/(?<AircraftOwner>([A-Z]{2}|.)))?(\s4\/(?<CockpitCrewEmployer>(.+?)(?=(?: \d\/|$))))?(\s5\/(?<CabinCrewEmployer>([A-Z]{2}|.)))?(?<OnwardFlight>\s6\/(([A-Z0-9]{2}[A-Z]?)([0-9]{3,4}))([A-Z])?(\/(\d{2})([A-Z]{3})?(\d{2})?)?)?(\s7\/(?<MealServiceNote>(\/?[A-Z]{0,3})+))?(\s9\/(?<OperatingAirlineDisclosure>(.{2}[A-Z]?)))?
I think there is no need to study the entire regex becasue it's build dynamically from smaller patterns at runtime and all the parts work correctly. Also lots of combinations are tested with unit tests and they all work... as long as I try to parse ony the line that should be matched by the pattern.
Currently I'm checking if the entire string is matched by
match.Group[0].Value == line
but I find it's quite ugly. I know from JavaScript the regex engine provides an Index property where the regex engine stopped. So my idea was to compare the index with the length of the string. Unfortunatelly I wasn't able to find such a property in C#.
Another idea would be to modify the regex so that it matches only one line and no partial lines.
Example: https://regex101.com/r/dM5wU4/1
The example contains only two cases because there aren't actually any combinations that would change its behavior. I could remove some parameters but it wouldn't change anything.
EDIT:
I've edited my question. Sorry to every for not providing all the information at the first time. I won't ask any more questions when writing on the phone :) It wasn't a good idea. Hopefully it won't get closed now.
You asked whether I could simplify the regex. I would do it if I could and knew how. If it was easy I wouldn't have asked. The problem started as the regex ans string became bigger during development. Now they are at the production length and I can't actually make them shorter even for the sake of the quesion, sorry.
EDIT-2:
I found the reason why I couldn't find the inherited Index and Length properties of the Match class.
For some strange reason when selecting the Match class and pressing F1 Visual Studio opened the wrong help page (Match Properties) even though I'm not working with the Micro Framework. I didn't notice that but I was indeed wondering why there is very little information. Thx to #Jamiec for the correct link. I won't trust Visual Studio anymore when hitting F1.
Disclaimer: Im going to add this, but I doubt its the solution. If it's not this part will get deleted in short order
You can add a $ at the end of your regular expression. This stops your first example matching but continues to match the second example.
As you've not provided any more than 2 examples, its unclear if this actually solves all your cases or just that one specific false positive.
My question is whether it is possible to check if a regular expression matched the entire sting without checking the first group against the original line?
If you're not adverse to checking the entire match to the length of the string you can do that too:
var regex = new Regex(#"^(?<FlightDesignator>([A-Z0-9]{2}[A-Z]?)([0-9]{3,4}))(?<OperationalSuffix>[A-Z])?(?<FlightIdentifierDate>\/(\d{2})([A-Z]{3})?(\d{2})?)?(\s(?<FlightLegsChangeIdentifier>(\/?[A-Z]{3})+)(?=(\s|$)))?(\s1(?<JointOperationAirlineDesignators>(\/.{2}[A-Z]?)+))?(\s3\/(?<AircraftOwner>([A-Z]{2}|.)))?(\s4\/(?<CockpitCrewEmployer>(.+?)(?=(?: \d\/|$))))?(\s5\/(?<CabinCrewEmployer>([A-Z]{2}|.)))?(?<OnwardFlight>\s6\/(([A-Z0-9]{2}[A-Z]?)([0-9]{3,4}))([A-Z])?(\/(\d{2})([A-Z]{3})?(\d{2})?)?)?(\s7\/(?<MealServiceNote>(\/?[A-Z]{0,3})+))?(\s9\/(?<OperatingAirlineDisclosure>(.{2}[A-Z]?)))?");
var input1 = #"BNE1010/1000 HKG1955/2005 7/PLD/CLD/YLD";
var input2 = #"RG878A/21AUG15 GIG/BOG 1/RG/AV 3/AV 4/AV 5/RG 6/AV081C/22 7/CDC/YD 9/TP";
var match1 = regex.Match(input1);
var match2 = regex.Match(input2);
Console.WriteLine(match1.Length == input1.Length); // False
Console.WriteLine(match2.Length == input2.Length); // True
Live example: http://rextester.com/NIBE6349

Does a .NET function exist that lets you pass in a string containing Regular Expressions and then return the possible matches?

Before I look into doing this myself, is there already a function out there that will do this:
I want to pass in a string containing text and RegEx markup and then it returns all possible matches it would look for in a string.
so the following passed to the method
abc|def|xyz
Would return 3 strings in an array or collection:
abc
def
xyz
Because that regex notation says to look for either abc, def or xyz.
I don't want this to search for the term in another string or anything like that, just return the possible matches it could make.
That's a simple example, anything that will do this for me, or shall I start writing the method myself?
With a simple regex as per your example it will work, but as soon as you start dealing with wild cards and repetition, it will have to generate almost an infinite amount of possible solutions, which in some cases may never even terminate.
No, it does not :)

Conditional Regex Replace in C# without MatchEvaluator

So, Im trying to make a program to rename some files. For the most part, I want them to look like this,
[Testing]StupidName - 2[720p].mkv
But, I would like to be able to change the format, if so desired. If I use MatchEvaluators, you would have to recompile every time. Thats why I don't want to use the MatchEvaluator.
The problem I have is that I don't know how, or if its possible, to tell Replace that if a group was found, include this string. The only syntax for this I have ever seen was something like (?<group>:data), but I can't get this to work. Well if anyone has an idea, im all for it.
EDIT:
Current Capture Regexes =
^(\[(?<FanSub>[^\]\)\}]+)\])?[. _]*(?<SeriesTitle>[\w. ]*?)[. _]*\-[. _]*(?<EpisodeNumber>\d+)[. _]*(\-[. _]*(?<EpisodeName>[\w. ]*?)[. _]*)?([\[\(\{](?<MiscInfo>[^\]\)\}]*)[\]\)\}][. _]*)*[\w. ]*(?<Extension>\.[a-zA-Z]+)$
^(?<SeriesTitle>[\w. ]*?)[. _]*[Ss](?<SeasonNumber>\d+)[Ee](?<EpisodeNumber>\d+).*?(?<Extension>\.[a-zA-Z]+)$
^(?<SeriesTitle>[\w. ]*?)[. _]*(?<SeasonNumber>\d)(?<EpisodeNumber>\d{2}).*?(?<Extension>\.[a-zA-Z]+)$
Current Replace Regex = [${FanSub}]${SeriesTitle} - ${EpisodeNumber} [${MiscInfo}]${Extension}
Using Regex.Replace, the file TestFile 101.mkv, I get []TestFile - 1[].mkv. What I want to do is make it so that [] is only included if the group FanSub or MiscInfo was found.
I can solve this with a MatchEvaluator because I actually get to compile a function. But this would not be a easy solution for users of the program. The only other idea I have to solve this is to actually make my own Regex.Replace function that accepts special syntax.
It sounds like you want to be able to specify an arbitrary format dynamically rather than hard-code it into your code.
Perhaps one solution is to break your filename parts into specific groups then pass in a replacement pattern that takes advantage of those group names. This would give you the ability to pass in different replacement patterns which return the desired filename structure using the Regex.Replace method.
Since you didn't explain the categories of your filename I came up with some random groups to demonstrate. Here's a quick example:
string input = "Testing StupidName Number2 720p.mkv";
string pattern = #"^(?<Category>\w+)\s+(?<Name>.+?)\s+Number(?<Number>\d+)\s+(?<Resolution>\d+p)(?<Extension>\.mkv)$";
string[] replacePatterns =
{
"[${Category}]${Name} - ${Number}[${Resolution}]${Extension}",
"${Category} - ${Name} - ${Number} - ${Resolution}${Extension}",
"(${Number}) - [${Resolution}] ${Name} [${Category}]${Extension}"
};
foreach (string replacePattern in replacePatterns)
{
Console.WriteLine(Regex.Replace(input, pattern, replacePattern));
}
As shown in the sample, named groups in the pattern, specified as (?<Name>pattern), are referred to in the replacement pattern by ${Name}.
With this approach you would need to know the group names beforehand and pass these in to rearrange the pattern as needed.

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