Substituting exact letter

Marcos Liell

I need to find and replace a letter, but it needs to be finished, it’s a music chord. Example: G I want to substitute for G , this is ok, but there are times that can be like this: G / B and if you ask to replace it it will look like this: G / B. How to differentiate G alone?

PeterJones

@Marcos-Liell said:

How to differentiate G alone?

It depends a lot on the circumstances. You didn’t give enough data for us to be sure.

However, based on my understanding of tabulature and other writing of musical chords, you want it to match a G, even if there are more spaces and chords after, but not if it’s a “G over B”, indicated with a slash between.

Thus, my mental rule becomes, look for a G, followed by 0 or more spaces, as long as there isn’t a slash after that.

Thus, my search regex becomes: (G)(\h*)(?![/\h]) – this looks for a G and stores it in memory $1, and stores the 0-or-more spaces in memory $2, and makes sure that the character after the 0-or-more-spaces is not a / (and also not a space, because otherwise, it just makes the \h* shorter), but doesn’t store or gobble that character.
and my replace is  $1 $2 – this replaces the match with your bold markup (I assume that’s what it is) around the matched G chord, followed by whatever spaces used to be there.
mode is regular expression, of course.

I made it easy to customize: if you want to change the chord you are searching for (like a Bb chord or F# chord), just change the G to something else; everything else in the regex is generic.

With the example data:

G   C   G   D   G   G
G / B   C   G   D   G/B G

it becomes

<b> G </b>   C   <b> G </b>   D   <b> G </b>   <b> G </b>
G / B   C   <b> G </b>   D   G/B <b> G </b>

Based on your description, I think it’s what you want… but I could be wrong. If that’s not correct, please be more explicit, giving examples of when to change and when not to change, showing before and after examples

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Marcos Liell

@PeterJones said:

(G)(\h*)(?![/\h])

Thank you very much, it worked. And to validate when the next character is a letter? Ex: Cords, I do not want you to be C ords

Thank you.

PeterJones

@Marcos-Liell said:

And to validate when the next character is a letter

So I would modify my textual description of the rules, using C as the example this time instead of G: “Find a C, not followed by an alphanumeric, followed by any number of spaces (including zero), not followed by a slash or space.”

The regex just needs to be modified to exclude (but not capture or gobble) a “word character” (basically, alphanumeric) when looking for the C, using (?!\w)… which means the final Find what = (C(?!\w))(\h*)(?![/\h]). The replacement stays the same

With the new example text:

C   G   D   C   C
C / E Chord C  Cm C

it would transform to

<b> C </b>   G   D   <b> C </b>   <b> C </b>
C / E Chord <b> C </b>  Cm <b> C </b>

If you have any more tweaks you’d like, please try reading some of the docs from the regex FAQ linked above, especially here. After reading that, try to make the modification yourself. If you cannot get it to work yourself, then show us how you modified the regex, and explain what you think it should be doing, and show us what it really does.

Marcos Liell

@PeterJones said:

(C(?!\w))(\h*)(?![/\h])

Thankyou Very Much

guy038

Hello @marcos-liell, @PeterJones and All,

Here is a second search regex which contains two consecutive structures : a negative look-ahead, followed with a positive look-ahead, containing, itself, a nested negative look-ahead !

So, this regex only searches for the upper-case C letter, but ONLY IF :

Not followed by a word character

AND

Followed with any range, even null, of horizontal blank characters
- But ONLY IF that range is not followed, itself, by a / symbol

Note the interesting use of the possessive quantifier *+, after \h. As no backtracking process may occur, we’re sure that, after the blank characters matched zone, there will be, necessarily, a non blank character ;-))

As we just grab the C character, we can use the $0 syntax, which, simply, represents… … the C letter !

Hence, the regex S/R, below :

SEARCH (?-i)C(?!\w)(?=\h*+(?!/))

REPLACE  $0 

Which gives the same result :

<b> C </b>   G   D   <b> C </b>   <b> C </b>
C / E Chord <b> C </b>  Cm <b> C </b>

Best Regards,

guy038

Marcos Liell

Thank you very much, it helped me a lot.

Another question, is there any plugin that can do this?

I would like to select with the Mouse the letter C, to press a button of atralho and to insert with this command the Tags in C?

Example: I select Letter C, press Crtl + 9 and insert as follows: C

Thank you

Alan Kilborn

@Marcos-Liell

I don’t know about a plugin…maybe. Maybe it is something NppExec plugin can do easily (experts on that could chime in…).

For myself, I turn to scripting for such things. Example: Create a short Pythonscript and bind it to the ctrl+9 key: editor.replaceSel('' + editor.getSelText() + '')

guy038

Hi, @marcos-liell, @PeterJones and All

May be, it’s worth to point out that the regex engine working position, does NOT change, when evaluating any look-around structure ! So, regarding my regex version, this working location is :

Between the upper-case C and its next character, when evaluating the negative look-ahead (?!\w)
Still, between the upper-case C and its next character, when evaluating the positive look-ahead (?=\h*+.....)
And still, between the upper-case C and its next character, when evaluating the nested negative look-ahead (?=....(?!/)

For instance, if we consider the following regex :

(?-i)C(?!\w)(?=\h*+(?!/))\x20\x20#

It would match, for instance, the string “C #” ( with 2 space chars between C and #). This means that, when the regex engine is about to evaluate the ending part of the regex \x20\x20#, its working location is, as expected, right after the C letter !

Now, after reflection and some tests, I thought about an other solution, using just 1 positive look-ahead :

SEARCH  :  (?x-i)  C  (?=  \h++[^/]  |  [^\w\h/]  )

REPLACE :  <b> $0 </b>

Note that I used the free-spacing regex mode, (?x), in order to easily see the main parts of the regex ;-))

So, the regex engine searches for an upper-case C ONLY IF , right after, there is :

A non-null range of horizontal blank characters, followed with a char, different from the / symbol ( => it can be an EOL char ! )

OR

A NON-word character, different from, both, an horizontal blank char and the / symbol

Cheers

guy038

Marcos Liell 0

@guy038 said in Substituting exact letter:

Hi, @marcos-liell, @PeterJones and All

May be, it’s worth to point out that the regex engine working position, does NOT change, when evaluating any look-around structure ! So, regarding my regex version, this working location is :

Between the upper-case C and its next character, when evaluating the negative look-ahead (?!\w)

Still, between the upper-case C and its next character, when evaluating the positive look-ahead (?=\h*+.....)

And still, between the upper-case C and its next character, when evaluating the nested negative look-ahead (?=....(?!/)

For instance, if we consider the following regex :

(?-i)C(?!\w)(?=\h*+(?!/))\x20\x20#

It would match, for instance, the string “C #” ( with 2 space chars between C and #). This means that, when the regex engine is about to evaluate the ending part of the regex \x20\x20#, its working location is, as expected, right after the C letter !

Now, after reflection and some tests, I thought about an other solution, using just 1 positive look-ahead :
SEARCH : (?x-i) C (?= \h++[^/] | [^\w\h/] )

REPLACE : $0 
Note that I used the free-spacing regex mode, (?x), in order to easily see the main parts of the regex ;-))

So, the regex engine searches for an upper-case C ONLY IF , right after, there is :

A non-null range of horizontal blank characters, followed with a char, different from the / symbol ( => it can be an EOL char ! )

OR

A NON-word character, different from, both, an horizontal blank char and the / symbol

Cheers

guy038

Thank you, it worked. There is only one problem, when replacing the chord it changes places because of the tag they go forward, would there be a way to move 3 spaces to the left when replacing? Thank you

guy038

Hello, @marcos-liell,

Oh, my God, I had to remember all this old discussion !

You said :

when replacing the chord it changes places because of the tag they go forward, would there be a way to move 3 spaces to the left when replacing?

It’s not very clear to me ! So, would you mind showing :

An example of your initial text
Which search and replacement regexes did you use
The resulting text that you obtained
And the text that you would expect to !

Thanks !

Best Regards,

guy038