Using sets to find A-Za-z plus the # and - chars ..?

PeterJones · Nov 17, 2022, 4:23 PM

@IanSunlun said in Using sets to find A-Za-z plus the # and - chars ..?:

Does [\w%#.~-]+ put whatever it matches into ${1} ?

Sorry, when I answered, I had forgotten that you previously said,

(So I need to store pagename in ${1} and bookmark in ${2}.)

Putting the # into either match is not what you want, either. You really need two groups, one before the # and one after.

FIND = http://mysitename.net/index.php/([\w%.~-]+)#([\w%.~-]+)"
will only match if there is a bookmark, and the # will not be inside the ${2} group. If you want the # to be included in ${2}, use http://mysitename.net/index.php/([\w%.~-]+)(#[\w%.~-]+)"

IanSunlun · Nov 17, 2022, 4:28 PM

@PeterJones said in Using sets to find A-Za-z plus the # and - chars ..?:

FIND = http://mysitename.net/index.php/([\w%.~-]+)#([\w%.~-]+) "

With the period . inbetween the % and the ~ it did not find:
http://mysitename.net/index.php/New_Video#column-one"
But taking the period out, it did find it.
Whats the thinking behind the period in this context ?

PeterJones · Nov 17, 2022, 6:46 PM

@IanSunlun ,

Except for -, order doesn’t matter inside the [] character class. The period is there because New.Video#column-one is also a valid URL ~~ender~~ end-string.

FIND = http://mysitename.net/index.php/([\w%.~-]+)#([\w%.~-]+)"
does match http://mysitename.net/index.php/New_Video#column-one":

Alan Kilborn · Nov 17, 2022, 7:46 PM

@PeterJones said in Using sets to find A-Za-z plus the # and - chars ..?:

FIND = http://mysitename.net/index.php/([\w%.~-]+)#([\w%.~-]+) "

Is it worth pointing out that the first two periods here really aren’t periods but rather “match any char”, because they aren’t escaped? Sure, an unescaped . will match a literal period, but it will match other things as well (obviously).

IMO, OP here needs to stop asking forum questions and go off and study regex.

guy038 · Nov 18, 2022, 11:58 AM

Hello, @peterjones,

In the post below, Peter :

https://community.notepad-plus-plus.org/post/81643

You said :

Actually, it’s not documented in our character classes section. I will remedy that.

Then, regarding the Character Class feature, may be, this part could be added to the Official Notepad++ Documentation : :

If we consider the following CHARACTER CLASS structure :

[.......]
123456789

The POSSIBLE location(s), in order to find the LITERAL character below, are :

LITERAL Character [    :     POSSIBLE at any position, BETWEEN 2 to 8 
                             POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character
							 
LITERAL Character ]    :     POSSIBLE at position 2 ONLY
                             POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character
							 
LITERAL Character -    :     POSSIBLE at position 2
                             POSSIBLE at position 8
                             POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character
							 
LITERAL Character \    :     POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character

Of course, change this layout as you like !

Best Regards,

guy038

Alan Kilborn · Nov 18, 2022, 2:14 PM

@guy038

It is rather awkward to express, but I like your idea.

My idea for expression:

To use a “literal [” in a character class: Use it directly like any other character, e.g. [ab[c]; “escaping” is not necessary (but is permissible), e.g. [ab\\[c]
To use a “literal ]” in a character class: Directly right after the opening [ of the class notation, e.g. []abc], OR “escaped” at any position, e.g. [\\]abc] or [a\\]bc]
To use a “literal -” in a character class: Directly as the first or last character in the enclosing class notation, e.g. [-abc] or [abc-], OR “escaped” at any position, e.g. [\-abc] or [a\-bc]
To use a “literal \” in a character class: Must be doubled (i.e., \\) inside the enclosing class notation, e.g. [ab\\c]

PeterJones · Nov 18, 2022, 2:14 PM

@Alan-Kilborn & @guy038 ,

I like those suggestions, especially the way Alan rephrased it: it works much better than my clunky first attempt in the manual, that only included - and was not not very readable.

Thanks.

Alan Kilborn · Nov 18, 2022, 3:22 PM

@PeterJones

Maybe my first-of-4 bullet points previously should be moved to be the last-of-4, and changed to:

To use any other literal character in a character class, just use it directly, i.e., no “escaping” needed

Maybe it works well as a 2 column 4 row table, headers:

Character
To use it literally in a character class

With those headers, the “cell contents” for column 2 could be appropriately shortened to remove redundant verbiage.

guy038 · Nov 18, 2022, 3:54 PM

Hi, @peterjones,

BTW, Peter, do you intend to include, in some way, the end part of this post, regarding the Free-space mode, which is in the Notes section ?

https://community.notepad-plus-plus.org/post/81368

Also, did you correctly receive, by e-mail, my attached text file, regarding the TextFX features ?

Please, I do not want to stress you, unnecessarily ! Just go at your own pace !

Best Regards

guy038

Alan Kilborn · Nov 18, 2022, 4:02 PM

@guy038 said in Using sets to find A-Za-z plus the # and - chars ..?:

do you intend to include, in some way, the end part of this post, regarding the Free-space mode

He already did, see HERE .

Andrew McP · Nov 19, 2022, 8:58 PM

@Alan-Kilborn I really admire you guys for figuring out Regular Expressions; I bet you never get lost in real life when you can keep track of the patterns/positions so well, aka good spatial awareness :)

Oh and I like the trick of having - as last character before ]

Alan Kilborn · Nov 19, 2022, 9:06 PM

@Andrew-McP said in Using sets to find A-Za-z plus the # and - chars ..?:

I really admire you guys for figuring out Regular Expressions

So if someone says they have “figured out regular expressions”, I pity them. Because it just means they are ripe for an upcoming whipping when a regex misunderstanding of theirs really embarrasses them. :-)

It pays to always be humble when discussing regular expressions with others. :-)

I bet you never get lost

GPS!

I like the trick of having - as last character before ]

Not so much a trick, as a logical place to put it when you realize that anywhere except the first or last position it must form some sort of “range”.

Andrew McP · Nov 19, 2022, 9:16 PM

@Alan-Kilborn hahahah yes no way would I bet my house on any regular expression I recommend covering all, no matter how perverse, eventualities…

guy038 · Nov 23, 2022, 11:35 PM

Hello, @peterjones,

In my previous post, I forgot to mention the ^ character, which has a special meaning within a Character class !

So, here is an updated version of my previous post :

If we consider the following CHARACTER CLASS structure :

[.......]
123456789

The POSSIBLE location(s), in order to find the LITERAL character below, are :

LITERAL Character [    :     POSSIBLE at any position, BETWEEN 2 to 8 
                             POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character
							 
LITERAL Character ]    :     POSSIBLE at position 2 ONLY
                             POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character
							 
LITERAL Character -    :     POSSIBLE at position 2
                             POSSIBLE at position 8
                             POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character

LITERAL character ^    :     POSSIBLE at any position, BETWEEN 3 and 8
                             POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character

							 
LITERAL Character \    :     POSSIBLE at any position, BETWEEN 2 to 8, if PRECEDED with an ANTI-SLASH character

And I suppose that @alan-kilborn could add :

To use a “literal ^” in a character class: Use it directly like any other character, e.g. [ab^c], but right after the opening [ of the class notation ; “escaping” is not necessary (but is permissible), e.g. [ab\^c]

Best Regards,

guy038