Find-in-FIles: Can’t Replace Multiple Instances of Word

Sylvester Bullitt

@PeterJones I tried the regex modification you suggested

(?:lyrics-text|\G).+?(?<!^)(?<!<p>)(?<!<p class="chorus">)\Kstar(?=(.+?</div>))

To keep it simple, I ran it against a single file in the editor (rather than multiple files on disk). The file text that was in the editor:

<!DOCTYPE HTML>
<html lang="en-us">

<head>
<meta charset="utf-8">
<title>Twinkle, Twinkle, Little Star</title>
<meta name="description" content="Words: Jane Taylor, 1806. Music: ___, ___">
<meta name="keywords" content="Jane Taylor">
<link rel="stylesheet" href="../../css/hymn.css">
<script src="../../js/jquery.js"></script>
<script src="../../js/base.js"></script>
<script src="../../js/hymn.js"></script>
<link rel="prev" href="../../htm/h/e/w/o/hewonsav.htm">
<link rel="next" href="../../htm/h/e/s/a/hesallwo.htm">
<link rel="up" href="../../ttl/ttl-h.htm">
</head>

<body>

<section id="preface">
<h1 class="screen-reader-only">Introduction</h1>
<div class="preface-text">
<p><span class="lead">Words:</span> <a href="../../bio/t/a/y/l/taylor_jane.htm">Jane Taylor</a>, 1806.</p>
<p><span class="lead">Music:</span> John Doe  (<a href="../../mid/d/u/m/m/dummy.mid" title="Listen to music, MIDI format">🔊</a> <a href="../../pdf/en/d/u/m/m/Dummy.pdf" title="Download score, PDF format">pdf</a> <a href="../../nwc/d/u/m/m/Dummy.nwc" title="Download score, Noteworthy Composer format">nwc</a>).</p>
</div>
</section>

<p>This page is used to test global search-and-replace using regular expressions.</p>

<section class="lyrics">
<h1 class="screen-reader-only">Lyrics</h1>
<div class="stanzas"><div class="lyrics-text mc ll">
<p>Twinkle, twinkle, little star,<br>
How I wonder what you are!<br>
Up above the world so high,<br>
Like a diamond in the sky.</p>
<p>When the blazing sun is gone,<br>
When he nothing shines upon,<br>
Then you show your little light,<br>
Twinkle, twinkle, all the night.</p>
<p>Then the trav’ller in the dark,<br>
Thanks you for your tiny spark,<br>
He could not see which way to go,<br>
If you did not twinkle so.</p>
<p>In the dark blue sky you keep,<br>
And often thro’ my curtains peep,<br>
For you never shut your eye,<br>
Till the sun is in the sky.</p>
<p>’Tis your bright and tiny spark,<br>
Lights the trav’ller in the dark:<br>
Tho’ I know not what you are,<br>
Twinkle, twinkle, little star.</p>
</div></div>
</section>

</body>
</html>

I put the cursor at the beginning of the file, clicked the Find Next button. and got this error.

If I click the Replace All button instead, a different message appears: Replace All: 0 occurrences were replaced in entire file.

PeterJones

@Sylvester-Bullitt said in Find-in-FIles: Can’t Replace Multiple Instances of Word:

The file text that was in the editor:

I tried that text with your original regex from your first post, and got the same result.

As I said, “if your original regex was working for doing a single replacement that had to be run multiple times”. Your text didn’t match your regex even once, thus the “if” condition was not met, and you should not expect my modification to work.

Sylvester Bullitt

@PeterJones Oops. Mea culpa.

Forgot to change the search mode to Regular Expression. After doing that, and clicking Replace All, all 3 occurrences were replaced in one fell swoop. Sorry for the confusion.

My next step is to try it on multiple files on the hard disk.

Whew!

PeterJones

@PeterJones said in Find-in-FIles: Can’t Replace Multiple Instances of Word:

I tried that text with your original regex from your first post, and got the same result.

My test of your regex+data was failing for a different reason than your test had failed: as you said, yours failed because you forgot to enable Regular Expression mode.

My test, on the other hand, failed because I didn’t have “. matches newline” checkmarked. Once I did that, I could get the search to work with either your original or my edited regex.

Sylvester Bullitt

@PeterJones I love it when a plan comes together!

Will let you know how testing goes “in the wild” (i.e., on actual files).

PeterJones

@Sylvester-Bullitt said in Find-in-FIles: Can’t Replace Multiple Instances of Word:

(?:lyrics-text|\G).+?(?<!^)(?<!<p>)(?<!<p class="chorus">)\Kstar(?=(.+?</div>))
…
all 3 occurrences were replaced in one fell swoop.

I was surprised it was 3 occurrences, because the first occurrence was before lyrics-text.

I was reminded that the \G can actually match the start of the text under certain circumstances. This isn’t 100% clear in the User Manual, but in the Boost Regex documentation that it links to, it says (emphasis mine),

The sequence \G matches only at the end of the last match found, or at the start of the text being matched if no previous match was found.

To prevent \G from matching the start, you need to make sure the first alternative consumes the \A: FIND = (?s)(\A.*?lyrics-text|\G).+?(?<!^)(?<!<p>)(?<!<p class="chorus">)\Kstar(?=(.+?</div>))
With that, it only finds and replaces 2 in your “Twinkle Twinkle” file, instead of 3.

Coises

This post is deleted!

PeterJones

@PeterJones said in Find-in-FIles: Can’t Replace Multiple Instances of Word:

This isn’t 100% clear in the User Manual,

I have tweaked the UM to include the phrase from the boost manual, to make it more clear. It is doubtful anything I write, especially regarding regular expressions, can be 100% clear. ;-)

Sylvester Bullitt

@PeterJones Peter, I’m unfamiliar with the syntax (?:lyrics-text|\G). It resembles a lookbehind, but all the lookbehinds I’ve seen look like (? <=a) (i.e., no colon). What exactly is this thing? Where is it documented?

Coises

@PeterJones said in Find-in-FIles: Can’t Replace Multiple Instances of Word:

To prevent \G from matching the start, you need to make sure the first alternative consumes the \A: FIND = (?s)(\A.*?lyrics-text|\G).+?(?<!^)(?<!<p>)(?<!<p class=“chorus”>)\Kstar(?=(.+?</div>))
With that, it only finds and replaces 2 in your “Twinkle Twinkle” file, instead of 3.

It might not matter in @Sylvester-Bullitt’s application, but it should be noted that if the file does not contain the text lyrics-text at all, the expression given will replace every occurrence of star.

Sylvester Bullitt

@Sylvester-Bullitt said in Find-in-FIles: Can’t Replace Multiple Instances of Word:

@PeterJones I love it when a plan comes together!

Will let you know how testing goes “in the wild” (i.e., on actual files).

Here’s the problem file:

<!DOCTYPE HTML>
<html lang="en-us">

<head>
<meta charset="utf-8">
<title>Mary Had a Little Lamb</title>
<meta name="description" content="Words: Sarah Hale, 1830. Music: None.">
<meta name="keywords" content="Sarah Hale">
<link rel="stylesheet" href="../../css/hymn.css">
<script src="../../js/jquery.js"></script>
<script src="../../js/base.js"></script>
<script src="../../js/hymn.js"></script>
<link rel="prev" href="../../htm/h/e/w/o/hewonsav.htm">
<link rel="next" href="../../htm/h/e/s/a/hesallwo.htm">
<link rel="up" href="../../ttl/ttl-h.htm">
</head>

<body>

<section id="preface">
<h1 class="screen-reader-only">Introduction</h1>
<div class="preface-text">
<p><span class="lead">Words:</span> <a href="../../bio/h/a/l/e/hale_sjb.htm">Sarah J. Hale</a>, 1830.</p>
<p><span class="lead">Music:</span> John Doe  (<a href="../../mid/d/u/m/m/dummy.mid" title="Listen to music, MIDI format">🔊</a> <a href="../../pdf/en/d/u/m/m/Dummy.pdf" title="Download score, PDF format">pdf</a> <a href="../../nwc/d/u/m/m/Dummy.nwc" title="Download score, Noteworthy Composer format">nwc</a>).</p>
</div>
</section>

<p>This page is used to test global search-and-replace using regular expressions. </p>

<section class="lyrics">
<div class="stanzas"><div class="lyrics-text mc ll">
<p>Mary had a little lambkin,<br>
Its fleece was white as snow.<br>
And everywhere that Mary went,<br>
The lamb was sure to go.<br>
He followed her to school one day,<br>
That was against the rule.<br>
It made the children laugh and play<br>
To see a lamb at school.</p>
<p>And so the teacher turned him out,<br>
But still he lingered near,<br>
And waited patiently about<br>
Till Mary did appear.<br>
And then he ran to her, and laid<br>
His head upon her arm,<br>
As if he said <q>I’m not afraid,<br>
You’ll keep me from all harm.</q></p>
<p><q>What makes the lamb love Mary so?</q><br>
The eager children cry.<br>
<q>‘Oh, Mary loves the lamb, you know,</q><br>
The teacher did reply.<br>
<q>And you each gentle animal<br>
In confidence may bind,<br>
And make them follow at your call,<br>
If you are always kind.</q> </p>
</div></div>
</section>

</body>
</html>

When I searched for lamb, it found the expected instances in the lyrics section (class = “lyrics-text”), but surprisingly, it also found Lamb in the <title>. But the regex, as I originally wrote it, said it should only find matches after the string lyrics-text.

Did adding /G change the behavior I think you mentioned that it might make subsequent searches start at the beginning of the file.

Sylvester Bullitt

@Coises Ships passing in the night.

I just made a post saying when I searched for the word lamb, it also found the word Lamb in the <title>, not just after lyrics-text. Search text:

<!DOCTYPE HTML>
<html lang="en-us">

<head>
<meta charset="utf-8">
<title>Mary Had a Little Lamb</title>
<meta name="description" content="Words: Sarah Hale, 1830. Music: None.">
<meta name="keywords" content="Sarah Hale">
<link rel="stylesheet" href="../../css/hymn.css">
<script src="../../js/jquery.js"></script>
<script src="../../js/base.js"></script>
<script src="../../js/hymn.js"></script>
<link rel="prev" href="../../htm/h/e/w/o/hewonsav.htm">
<link rel="next" href="../../htm/h/e/s/a/hesallwo.htm">
<link rel="up" href="../../ttl/ttl-h.htm">
</head>

<body>

<section id="preface">
<h1 class="screen-reader-only">Introduction</h1>
<div class="preface-text">
<p><span class="lead">Words:</span> <a href="../../bio/h/a/l/e/hale_sjb.htm">Sarah J. Hale</a>, 1830.</p>
<p><span class="lead">Music:</span> John Doe  (<a href="../../mid/d/u/m/m/dummy.mid" title="Listen to music, MIDI format">🔊</a> <a href="../../pdf/en/d/u/m/m/Dummy.pdf" title="Download score, PDF format">pdf</a> <a href="../../nwc/d/u/m/m/Dummy.nwc" title="Download score, Noteworthy Composer format">nwc</a>).</p>
</div>
</section>

<p>This page is used to test global search-and-replace using regular expressions. </p>

<section class="lyrics">
<div class="stanzas"><div class="lyrics-text mc ll">
<p>Mary had a little lambkin,<br>
Its fleece was white as snow.<br>
And everywhere that Mary went,<br>
The lamb was sure to go.<br>
He followed her to school one day,<br>
That was against the rule.<br>
It made the children laugh and play<br>
To see a lamb at school.</p>
<p>And so the teacher turned him out,<br>
But still he lingered near,<br>
And waited patiently about<br>
Till Mary did appear.<br>
And then he ran to her, and laid<br>
His head upon her arm,<br>
As if he said <q>I’m not afraid,<br>
You’ll keep me from all harm.</q></p>
<p><q>What makes the lamb love Mary so?</q><br>
The eager children cry.<br>
<q>‘Oh, Mary loves the lamb, you know,</q><br>
The teacher did reply.<br>
<q>And you each gentle animal<br>
In confidence may bind,<br>
And make them follow at your call,<br>
If you are always kind.</q> </p>
</div></div>
</section>

</body>
</html>

It sounds like your comment addresses that. Am I correct?

PeterJones

@Sylvester-Bullitt said in Find-in-FIles: Can’t Replace Multiple Instances of Word:

Ships passing in the night.

More than that, you aren’t noticing all the posts because of the rapid posting.

I already explained exactly what happened with \G ion this post, which contains a fix for the \G issue.

@Coises’s follow-on showed that if any of your files don’t have lyrics-text at all, then my fix-for-\G will replace all instances of star or lamb or what have you – but I’m hoping, for your sake, that all the files that your Find in Files filter will match will contain lyrics-text somewhere.

PeterJones

@Sylvester-Bullitt said in Find-in-FIles: Can’t Replace Multiple Instances of Word:

(?:lyrics-text|\G)

(?:...) is a non-capturing subgroup.

Coises

@PeterJones said in Find-in-FIles: Can’t Replace Multiple Instances of Word:

@Sylvester-Bullitt said in Find-in-FIles: Can’t Replace Multiple Instances of Word:

Ships passing in the night.

More than that, you aren’t noticing all the posts because of the rapid posting.

I already explained exactly what happened with \G ion this post, which contains a fix for the \G issue.

@Coises’s follow-on showed that if any of your files don’t have lyrics-text at all, then my fix-for-\G will replace all instances of star or lamb or what have you – but I’m hoping, for your sake, that all the files that your Find in Files filter will match will contain lyrics-text somewhere.

Took me this long to get it (so I’ll post here rather than editing my earlier comment), but I think:

(?s)(\A.*?(lyrics-text|\Z(*COMMIT)(*FAIL))|\G).+?(?<!^)(?<!<p>)(?<!<p class="chorus">)\Kstar(?=(.+?</div>))

fixes that problem.

Sylvester Bullitt

@PeterJones Three things:

Yes, all the files (assuming they’re generated properly from my template) have the string lyrics-text.
I just tried Coises’ suggested modification to the regex:

(?s)(\A.*?lyrics-text|\G).+?(?<!^)(?<!<p>)(?<!<p class=“chorus”>)\Klamb(?=(.+?</div>))

As advertised, it no longer matches the Lamb in the <title> tag, which is the desired behavior, since we’re only changing lyrics.

What is the construct that resembles a lookbehind, but has the asterisk & question mark? That is,

(\A.*?lyrics-text|\G)

Still testing, but things are looking more and more promising!

Sylvester Bullitt

@PeterJones “I see,” said the blind carpenter, as he picked up his hammer and saw!

Coises

@Sylvester-Bullitt