Replace characters inside a RegEx match

Question

I want to match certain lines inside any text and inside that match, I want to replace a certain character as often, as it occurs. Sample Text:

Any text and "much" "more" of it. Don't replace quotes here
CatchThis( no quotes here, "any more text" , "and so on and so forth...")
catchthat("some other text" , "or less")
some text in "between"
CatchAnything ( "even more" , "and more", no quotes there, "wall of text")
more ("text"""") and quotes after...

Now I want to replace every quote inside the round brackets with, lets say, a hash sign. Desired outcome:

Any text and "much" "more" of it. Don't replace quotes here
CatchThis( no quotes here, #any more text# , #and so on and so forth...#)
catchthat(#some other text# , #or less#)
some text in "between"
CatchAnything ( #even more# , #and more#, no quotes there, #wall of text# )
more ("text"""") and quotes after...

Matching the lines is easy. Here's my pattern for that:

(?i)Catch(?:This|That|Anything)[ \t]*\(.+\)

Unfortunately, I have no idea how to match every quote and replace it...

score 6 · Accepted Answer · edited Sep 24 '17 at 05:08

6

The common approach to matching all occurrences of some pattern inside 2 different delimiters is via using \G anchor based regular expression.

(?i)(?:\G(?!\A)|Catch(?:This|That|Anything)\s*\()[^()"]*\K"

See the regex demo.

Explanation:

(?i) - case insensitive modifier
(?: - a non-capturing group matching 2 alternatives
- \G(?!\A) - a place in the string right after the previous successful match (as \G also matches the start of the string, the (?!\A) is necessary to exclude that possibility)
- | - or
- Catch(?:This|That|Anything) - Catch followed with either This or That or Anything
- \s* - 0+ whitespaces
- \( - a literal ( symbol
) - end of the non-capturing group
[^()"]* - any 0+ chars other than (, ) and "
\K - a match reset operator
" - a double quote.

edited Sep 24 '17 at 05:08

Graham

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answered Jun 14 '17 at 06:28

Wiktor Stribiżew

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Very nice! Just what the doctor ordered. Working perfectly...and big thx for the explanation! – TheFriesel Jun 14 '17 at 06:42
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Just in case you need to match multiple tokens in between *multi*character delimiters, I can advise using a ["tempered greedy token"](https://stackoverflow.com/a/37343088/3832970) instead of a negated character class (here, `[^()"]*` is used). – Wiktor Stribiżew Jun 14 '17 at 06:47
Thanks for the heads up! I'll look it up, but first, I have to fully understand your pattern ;) – TheFriesel Jun 14 '17 at 07:00
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Please let me know which parts confuse you and I will update the answer. – Wiktor Stribiżew Jun 14 '17 at 07:00
Much appreciated, Wiktor! I get the single parts, just the whole pattern has not sunk in (yet). Atm, I don't think, I could come up with such a solution by my self, but give it time ;) – TheFriesel Jun 14 '17 at 07:25

score 0 · Answer 2 · answered Jun 14 '17 at 06:10

0

Do you really need to replace this inside regex? If your regex finds what you want, you can replace character on found string

answered Jun 14 '17 at 06:10

Pablo notPicasso

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That's, what I'm doing right now: get an array of matches, replace the quotes and inject the modified matches back into the original text. Its pretty elaborate and I though, directly replacing inside the matches is much more elegant and maybe faster... – TheFriesel Jun 14 '17 at 06:16

Replace characters inside a RegEx match

2 Answers2