I think I have made a very obvious mistake. I forgot to specify my search flag as you mentioned in my other post. After switching it to Regexp, it seems to be working. I feel like that was very obvious and you have taken a lot of your time to help me, so thank you again for all your help.

If anything else happens, I’ll post again. Thanks.

Did you start npp from within Visual Studio or did you attach (from Debug menu) npp to visual studio? If so, those should appear in
View->Output window.

Okay, I’m trying that now. I am using visual studios and I have added in my code a OutputDebugStringW, now where would I find the values that it outputs when I use my plugin in notepad?

ok, then I would say it is time to debug/print some info about
target_start, target_end and position found.
Make a debug build, use OutputDebugStringW and tools like DebugView
to capture the output. Of course only, if you can’t run within Visual Studio.

Sorry, I am increasing the start by 2, I just didn’t clarify that. I meant that when I said, “Set the beginning of the target search area just ahead of where “<” is now found”. My mistake. I know my code works because when I select the text,

<<<<

it results in

<
<
<
<

Sorry for the confusion

From your explanation this doesn’t work.
You need to advance the start by 2, correct?
Assuming the following, 0123… are positions made visible.

0123456789
ab<def<h

position of < is 2 correct?
Insert c at that position results in

0123456789
abc<def<h

and if you set the start now to position+1 (=3) it will re-find the same <

Sure this is what you do?
My pseudocode would look like this

target = selected text
target_end = last position of selected text
position = search in target for '<'
while position > -1:
    insert char '\n' at position 
    reset target_start to position+2 and target_end to target_end+1
    position = search in target for '<'

Sure. This plugin just places a “\n” infront every case of “<” in the selected area.

function(){

Set the target search area to the area that has been selected.

Look for the first case of “<” in the targeted area.

While a, “<” can be found, get the placement of, “<”, insert a “\n” at that spot. Set the beginning of the target search area just ahead of where “<” is now found and increase the end of the target search area by 1. Search again for the next “<” in the target search area

}

yes, it could be that this is not the issue, but a new npp start also means that your data is not the same as before,
but you certainly have more information to evaluate this than I do,
I am fishing here more or less in the dark.
Can you describe in pseudocode what you are doing, maybe this could be helpful to find the issue.

I see what you mean, but I don’t think that applies to my situation as when my plugin fails, I can simply reopen notepad and continue to format some more content until it fails again. If this issue was happening to every instance of content all of the time then I could see why this makes sense.

yes, could be but to me it sounds more like an issue with the “new” content.
For example, let’s say we have a text like this

This is a sampl of a text which has two wrong words named sampl.

Now let’s assume your plugin is used to auto correct wrong words.
If your code logic would be

1. find all instances of the wrong word
2. Loop over the results and replace with the correct word

then it would fail as you invalidate the position of the second sampl
word by replacing the first one.
In such a scenario replacing from bottom to top would avoid this.
Of course, there are multiple other ways to solve this issue as well.

Thanks, I’ll try that.

There is another thing I have noticed and I wonder if you could help me with it. The text file I am working on is around 40’000 lines long, and as I said before I am formatting small parts of that file and eventually it will start to mess up. What I have noticed though, is that when I copy and paste a part of the original text file to a separate notepad tab and try to format it, then once it’s formatted it, delete it and then repeat the process, the formatting process never messes up. Could it be that the length of the text file has something to do with how many times I can use my plugin on it?

until it fails and then won’t work until I restart notepad

yes, that could mean that you have an overflow.
There are several ways to find out what is causing it.
Old school, use print statements in your code and check certain parameters.
More modern, use Visual Studios features like Analyzer and Debugger to see what is going on.
I assume you are using Visual Studio for development,
there is one setting I would suggest to activate, it is to treat every warning as an error.
(Project->Properties->Configuration Properties->C/C+±>General->Treat warnings as errors->Yes)

Sorry, but there is a small, but unfortunately insurmountable problem,
I cannot program in C++, I am a python junkie :-)

There are several possible data types that can be used, but without knowing your code and concept, it is hard to say what to use.
Personally, I would use INT_PTR, but if your result is ever converted to long, I would probably use LONG_PTR.

So how would I prevent it from overflowing?

Not sure I understand this question because I guess you know the obvious answer,
which would be “use a datatype which is big enough to hold the values”, yourself.

By the way, you defined your start and end being ints.
But SendMessage returns an LRESULT which is defined as LONG_PTR, so just be careful because a position might overflow it.

Okay, thanks, as I said, I have limited experience with any of this stuff. I have only just started to program and I really appreciate you helping me out.

I understand, I’m not a programmer but have muddled my way through Scintilla docs and other N++ plugins and been able to hack together some working code.

@Ekopalypse has it right about Unicode / ANSI. By default, all N++ plugins are compiled for Unicode as N++ no longer published an ANSI version. So the difference in your plugin when handling text in N++ documents (like searching for it) is to expect Unicode.

You’ll probably see character strings in N++ plugins initialized with:

TCHAR cString[MAX_PATH];

since this can be ANSI or Unicode depending on compiler switches and that was needed back when there was an ANSI N++.

https://docs.microsoft.com/en-us/office/client-developer/outlook/mapi/tchar

Cheers.

After testing, SCI_TARGETFROMSELECTION, I think you may have been right. This seems to have fixed it