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

guy038

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

@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

@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

@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

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

@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

@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

@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

@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

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