Search++: A work in progress

guy038

Hi, @coises and All,

Ah…, many thanks, in avance, for resolving bugs and trying to take into account my suggestions !

Regarding the Search++.pdb file, I can, of course, try to re-download the x64 archive. But can I, without any problem, simply delete this present file in my Search++ folder ?

BR

guy038

Coises

@guy038 said in Search++: A work in progress:

Regarding the Search++.pdb file, I can, of course, try to re-download the x64 archive. But can I, without any problem, simply delete this present file in the Search++ folder ?

Yes.

guy038

Hello, @coises and All,

Sorry to disturb you again, but would it be possible to, either :

Increase the width of the caret

OR

Allow, like in native N++, the modification of its width, in your Settings dialog

Personally, I use the value 3 in Caret Settings in Notepad++ and yours seems really tiny. So, it rather difficult to notice the caret location at first sight, in the Find dialog !

I must admit that I probably get used to this maximum value for the caret and that, now, any smaller size bothers me a bit !

Best Regards,

guy038

Coises

@guy038 said in Search++: A work in progress:

Sorry to disturb you again, but would it be possible to, either :

Increase the width of the caret

OR

Allow, like in native N++, the modification of its width, in your Settings dialog

I will add that to the list of things I copy from the the active document window when I initialize my Scintilla controls, and look for other similar settings (like the blink rate) that I missed. Not everything is simple to copy, but those are.

Thank you for pointing that out.

guy038

Hello, @coises and All,

I finally succeeded to get an almost exhaustive list of all the Unicode properties recognized by the ICU regex engine of the Search++ plugin !

As its file size is adbout 213 Kb, I’m about to share this simple text file, named ICU.txt, on my Drive Account

https://drive.google.com/file/d/15n8ttdX0hNxIazlRkToZn2XsINus5IOW/view?usp=sharing

Of course, this is my first attempt, which probably will need some modifications !

Best Regards,

guy038

Coises

@guy038 said in Search++: A work in progress:

I finally succeeded to get an almost exhaustive list of all the Unicode properties recognized by the ICU regex engine of the Search++ plugin !

[…]

https://drive.google.com/file/d/1litn6Ggjk-nRc8UOuxYS-5iO10_J-Z_2/view?usp=sharing

Edit to match updated quoted post: the link is now

https://drive.google.com/file/d/15n8ttdX0hNxIazlRkToZn2XsINus5IOW/view?usp=sharing

That clearly entailed a lot of work!

When I get closer to a “real” release, I will ask your permission to include some or all of that information as an appendix in the documentation for Search++.

guy038

Hi, @coises,

That’s really kind of you to ask for my permission.But, considering all the times you’ve listened to me, the least I can do is, of course, give you my full permission to use this file ;-))

Just note that I noticed, at the very end of the ICU.txt file, a small section that I used to verify if the \p{...} syntaxes were written correctly

As this part should not be part of the file, I modified the current file which, of course, changed the sharing link ! And I’ve just updated this link in my previous post !

Best Regards,

guy038

guy038

Hello, @coises and All,

Here is the second version of my list of all the Unicode properties, recognized by the ICU regex engine of the Search++ plugin !

I added 5 Unicode properties and some sections ( unsupported features, deprecated properties,… ) and I corrected a lot of mistakes !

In addition, although the ICU syntax is very flexible, I tried to adopt the same scheme throughout all sections of this file !

You can download this text file, named ICU.txt, from my Drive Account, at this location :

https://drive.google.com/file/d/1PAY5C2JO0q4-j8kfGKYs3VKarKn_xVa5/view?usp=sharing

Of course, I also deleted the previous version !

Now, one question regarding ICU

So far, you have chosen to disable replacements when using the ICU regular expression engine. What is that, exactly :

Are you worried about a possible malfunction of that feature ?
Are there any technical obstacles to implementing such a feature ?
Do you need more time to learn about and/or implement this feature ?
Or did you simply decide that it would never be used ?

Personally, I don’t see why this should be any more complicated than when using the Boost search engine when you click on the Regex button of your plugin !

Best Regards,

guy038

Coises

@guy038 said in Search++: A work in progress:

Now, one question regarding ICU

So far, you have chosen to disable replacements when using the ICU regular expression engine. What is that, exactly :

Are you worried about a possible malfunction of that feature ?

Are there any technical obstacles to implementing such a feature ?

Do you need more time to learn about and/or implement this feature ?

Or did you simply decide that it would never be used ?

Personally, I don’t see why this should be any more complicated than when using the Boost search engine when you click on the Regex button of your plugin !

The Boost.Regex design includes an interface that accesses the text to be searched through a templated iterator. That’s a bit of a technical C++ concept. In short, template means that the programmer can specify what sort of value will be matched (I chose a full Unicode code point, UTF-32) and iterator means that rather than giving the interface a single, contiguous block of memory filled with the value type, you give it a kind of index and separately write routines that return the value at that index; increase the index to the index of the next value; and decrease the index to the index of the previous value.

Scintilla stores documents in two separate blocks with a gap between — this facilitates inserting and deleting text without having to move all the following data every time — and it stores the data either in the system default encoding (“ANSI”) or in UTF-8. The template-and-iterator concept works well with this. Notepad++ search works that way, but there were technical reasons I did not want to use the same iterator code Notepad++ uses. Writing the three iterators I needed (one for single byte character sets, one for double-byte character sets, and one for UTF-8) was one of the trickier parts of getting my Columns++ search to work. Writing the template specialization for the “character traits” of my UTF-32 values was also a bit of work.

When doing a replacement, Boost.Regex takes a structure that is produced as a result of a match and the replacement string with symbols ($1, etc.) and returns the string with replacements, etc. made. From that, I use normal Scintilla editing commands to replace the matched string with the processed replacement.

The regular expression search in ICU is not templated. It operates strictly in UTF-16. It does not use iterators, but it does have its own way of virtualizing the text to be searched (UText). The only format directly supported by UText that is also used in Scintilla is UTF-8. Scintilla does accept a command to make all its text contiguous (moving the gap to the end), after which the text can be accessed — so long as the text is not modified and only until the next Scintilla call is performed — as a UTF-8 string. By limiting ICU search to only UTF-8 documents and allowing no modification, I could use the utext_openUTF8 interface to access the internal Scintilla buffer (after telling Scintilla to make it contiguous) in a way that is acceptable to the ICU regular expression matching interface.

The Find and Replace operation in ICU Regular Expressions is, to me, very strange. The documented way to use it is to build a new text that reproduces the entire source text, with replacements. That would make sense when reading a file and writing a new file; but it is, to me, not obvious how to apply it sensibly in the context of a text editor.

It’s probably possible to do everything necessary for good integration with Scintilla with ICU regular expressions, it’s just a big task, starting with learning more about how their UText extensibility works. I saw enough to think that it could be made to work on “ANSI” documents, it would just be a whole other side project in itself to figure out how. (The problem with just converting the document to Unicode is that you wind up with the starting and ending character positions of a match in the converted text, but no good way to convert those to positions in the original text, which is what you need to select the match in Scintilla.) Beyond the “ANSI” problem, forcing Scintilla to move its gap to the end before each search is not ideal, and for large documents that are being changed (as in find and replace) the performance loss would be bad. So even for Unicode I would need to write a different UText extension that doesn’t require contiguous UTF-8.

Then there’s analyzing that replacement logic and figuring out how to use it in a way that makes sense in Scintilla. It might be easier to implement replacements from scratch and completely ignore ICU’s replacement logic and syntax: based on what documentation exists, it seems likely that their supported syntax is very limited — none of the fancy stuff in Boost.Regex extended format strings. (Unfortunately, I couldn’t just use the Boost.Regex formatter, because it depends on the structured data produced by a Boost.Regex match, which is different than the structured data produced by an ICU match.)

Since I haven’t dug deeply into how ICU implements regular expressions, I can’t say how difficult it might be to customize or extend them. I have a better (not by any means comprehensive!) idea of what might be possible with Boost.Regex. Because of that, and because Notepad++ users are familiar with Boost.Regex syntax, I judged that it will probably be more practical to extend Boost.Regex with some features from ICU than to extend ICU toward Boost.Regex. Honestly, I don’t see the detailed Unicode properties of ICU as being nearly so valuable in practical, real-world use as the features Boost.Regex has that ICU doesn’t (\K and backtracking control are the ones I remember).

I do hope to extend the Boost.Regex implementation further. I’d like to implement Unicode word boundaries, but I haven’t yet gone into it deeply enough to determine whether it is practical. There might be a way to expose arbitrary Unicode properties, but that is also something I will have to study further. The biggest thing I’d like to do is figure out how to get a progress monitoring hook inside the matching process, so that annoying “too complex” message could be replaced by the ability to click cancel on a progress dialog — I know that will be challenging, and maybe not possible. I want to get the framework supporting what I have now up to a level where I feel that I can responsibly release it without classifying it as a “pre-release” before I get into those projects.

In the ICU search, I mostly included the stuff that was relatively easy — that I could copy from the same logic used for Plain and Regex. I thought it might serve as a good comparison test for whether I had implemented Unicode properties correctly in Regex — where there is a discrepancy, I should know why (such as my “ignore case insensitivity for character classes” rule). So I expected to leave it for future use to check as I try to extend Boost.Regex some more, but I thought I would probably hide it so users wouldn’t stumble over it. I never really thought it would be something many (any?) users would want.

The bottom line is that I only have so much time and capacity for concentration, and I don’t think making ICU regular expressions fully functional is likely to be the best use of it — at least not yet.

guy038

Hi, @coises,

Many thanks for your very exhaustive answer ! So OK, I understand that the ICU replacement seems really difficult to implement !

In my opinion, as the replacement syntax seemed simpler when using ICU than when using Boost, I naively thought that a solution could be implemented enough easily !

Sorry for my noob approach of the problem. And given what I now know, I won’t dare ask you about specific topics like this one, again . Just follow your train of thought, which I am convinced ,will lead to a polished final Search++ plugin !

BR

guy038