Backward regular expression searching disabled

ArkadiuszMichalski

@Alan-Kilborn
Such hidden settings should simply be documented, that’s enough. If we don’t know about their existence, why introduce them? I opened the bug in the manual https://github.com/notepad-plus-plus/npp-usermanual/issues/94

Alan Kilborn

@ArkadiuszMichalski

You miss my point, but that’s okay. Not everybody is going to “get it” and everyone can have their own opinion (there’s a famous quote about that). And I see from recent issues on github that you are quite opinionated. :-)

Michael Vincent

@ArkadiuszMichalski said in Backward regular expression searching disabled:

Such hidden settings should simply be documented, that’s enough.

My favorite is:

        <GUIConfig name="commandLineInterpreter">powershell</GUIConfig>

Which makes the menu File => Open Containing Folder => cmd actually open PowerShell instead of cmd.exe.

Cheers.

ArkadiuszMichalski

@Michael-Vincent
Thx, I add your tip to an open bug in the manual. If anyone knows any other hidden settings, please add them directly in the opened bug, it will be easier to describe them later in the manual.
https://github.com/notepad-plus-plus/npp-usermanual/issues/94

Alan Kilborn

As part of these scripts I’d like to show a “call tip”.
I can’t seem to make Pythonscript do it, but having never used a call tip before I’m maybe not sure of all I need to do.

If I try this in the PS console:

editor.callTipShow(editor.getCurrentPos(), 'blah')

and do it repeatedly, I think I can sometimes see the call tip pop up briefly, and then vanish.

What am I doing wrong?
Is there more that I need to do?
I looked through all of the calltips functions and didn’t see anything relevant:

editor.callTipActive() 
editor.callTipCancel()
editor.callTipPosStart() 
editor.callTipSetBack(back)
editor.callTipSetFore(fore)
editor.callTipSetForeHlt(fore)
editor.callTipSetHlt(start, end)
editor.callTipSetPosStart(posStart)
editor.callTipSetPosition(above)
editor.callTipShow(pos, definition)
editor.callTipUseStyle(tabSize)

Help! @Ekopalypse ?

Ekopalypse

@Alan-Kilborn

works as long as the editor has the focus but running from console
puts focus back to textbox control. If you run this within a script you will see it does show blah.

Alan Kilborn

@Ekopalypse

Ah! Okay, thanks. It seems like I did start within a script and had trouble with it, so (usual debug technique) I was trying console operations to isolate. Looks like this is a case where console ops make it worse, not better. I’ll get back to my script now. :-)

Alan Kilborn

Well there’s nothing like trying to tackle a problem to show you how difficult it is. :-)

And I wasn’t even initially trying to do backward regex searching.

I was trying to do a forward search, while considering the caret position.

And there were cases that came up that it was just, well, very difficult to handle.

For instance, if you search the whole file for matches and then try to select the one at or further on from the caret position (this was the base algorithm), you have a problem if your regex match starts before your caret position and due to a greedy expression it blows through and beyond your caret position. Then you have no frame of reference for really where (to the right of your caret) you really should match. (Starting the search at the caret position doesn’t help because I wanted to handle lookbehinds correctly with this).

This probably doesn’t make much sense; you have to “get close to the problem” to fully understand it, perhaps.

So, anyway, new respect for those that can write this algorithm correctly!

Alan Kilborn

@Alan-Kilborn said in Backward regular expression searching disabled:

So, anyway, new respect for those that can write this algorithm correctly!

And, to date, I’m NOT including the Notepad++ developers in this “respect” (sorry!), because most of us have read the complaints about matching that logically seems like it should occur but doesn’t, i.e., this scenario:

Text:

ab

Caret between the a and the b.

Regex search for (?<=a)b won’t match the b.

guy038

Hello @alan-kilborn and All,

Don’t forget that, in addition to the basic algorithms, used in our modern regex engines, they usually perform a lot of internal optimizations. For instance, to avoid backtracking process, dead-end searches and other goodies !

Such a big task, indeed !

Regarding your example :

if the Wrap around option is not ticked the regex matches the b letter, ONLY IF the caret location is before the a letter
if the Wrap around option is ticked, obviously, the regex matches the b letter, whatever the caret location !

Not that, with the enhanced regex engine of François-R Boyer, and tested with N++ v6.9, it does match the b letter with :

The Wrap around not ticked
The caret located between letters a and b

Best Regards,

guy038

Alan Kilborn

@guy038 said in Backward regular expression searching disabled:

with the enhanced regex engine of François-R Boyer

Too bad we can’t dust off Monsieur Boyer and get him to do some more work on Notepad++ codes! :-)

Regarding your example

Right. The example was done because everyone wants it to work like I suggested (via counterexample). Because you can logically see the “a” there before the “b”. Nothing more.

Nobody wants to do crazy workarounds (or have to keep in mind some special things) to find it. Workarounds are fine, but situations like the one I described are potential time suckers: “Notepad++ said my data was not matched, so I spent an hour or 2 working from the assumption that it was right and did this and that and blahblahblah and in the end it was all for nothing, because of the original “lie” that was told”.

Makwana Prahlad

Hello,@Alan-Kilborn

Follow this step,To Backward regular expression searching disabled

Step 1:- Start Notepad++ 7.5 (32-bit) from a fresh unzip of the portable install.
Step 2:- Execute any Find operation with Regular Expression as the search mode (note that when the search mode is changed to Reg Exp the “backward direction” checkbox becomes disabled–correct behavior).
Step 3:- Quit and restart Notepad++ 7.5.
Step 4:- Invoke the Find dialog. Note that the search mode is Reg Exp but the “backward direction” checkbox is now incorrectly enabled.

I hope this information will be useful for you.
Thank You.