Need Help Guys (Regex) : I have a regex and it works as expected in All Platforms except Kotlin/JS ...

# javascript

[Shabinder Singh]

Need Help Guys (Regex) :

I have a regex and it works as expected in All Platforms except Kotlin/JS
REGEX:

"""ytInitialPlayerResponse\s*=\s*(\{.+?\})\;var meta""".toRegex()

*ERROR*(only in Kotlin/JS):

SyntaxError: Invalid regular expression: /ytInitialPlayerResponse\s*=\s*(\{.+?\})\;var meta/: *Invalid escape*
at <global>.new RegExp(<anonymous>)

However this same regex works fine online in a Regex Editor/Tester , link: https://regex101.com/r/WZT1Pr/1/

Any Help would be Appreciated!

[Robert Jaros]

It's probably connected, because you regexp works fine with Kotlin 1.4: https://youtrack.jetbrains.com/issue/KT-46694

[Robert Jaros]

Try not escaping ; sign

[Shabinder Singh]

lemme try

[Shabinder Singh]

That did the trick, Thanks @Robert Jaros

[Shabinder Singh]

@Robert Jaros Again Faced Related Issue:

"""\{var\s\w=\w\[0];\w\[0]=\w\[\w%\w.length];\w\[\w]=\w\}""".toRegex()

SyntaxError: Invalid regular expression: /\{var\s\w=\w\[0];\w\[0]=\w\[\w%\w.length];\w\[\w]=\w\}/: Lone quantifier brackets

But Online Regex detect it as valid

Edit: Fixed It. removed extra \

"\\{var\\s\\w=\\w[0];\\w[0]=\\w[\\w%\\w.length];\\w[\\w]=\\w\\}".toRegex()

[Robert Jaros]

try: """\{var\s\w=\w\[0\];\w\[0\]=\w\[\w%\w.length\];\w\[\w\]=\w\}""".toRegex()

[Shabinder Singh]

After Updating to 1.5.31, Again hit this,

SyntaxError: Invalid regular expression: /"\{var\s\w=\w\[0];\w\[0]=\w\[\w%\w.length\];\w\[\w]=\w\}/: Lone quantifier brackets
at <global>.new RegExp(<anonymous>)
at <global>.Regex(/home/shabinder/IdeaProjects/youtube-api-dl/build/js/packages_imported/kotlin/1.5.31/js/src/kotlin/text/regex.kt:56)
at Regex.init(/home/shabinder/IdeaProjects/youtube-api-dl/build/js/packages_imported/kotlin/1.5.31/js/src/kotlin/text/regex.kt:49)

Regex cant be used reliably in multiplatform context I guess.... blob thinking upside down

[ephemient]

you need to escape the \]

[ephemient]

browser are all strict about JS RegExp syntax when using /u Unicode mode, as Kotlin does

[Shabinder Singh]

will that affect JVM or other platforms ?
lemme try

[ephemient]

just use Robert's version, it is already corrected

[ephemient]

in this case it should be fine across all platforms, but JS RegExp and Java Pattern aren't the same regex language so many constructs are not portable across platforms

[Shabinder Singh]

Thanks that did the trick again, I forgot try earlier suggestions,

But now getting an illegal escape, really JS is quite strict,

Invalid regular expression: /yka=function\(\w\)\{[a-z=\.\(\"\)]*;(.*);(?:.+)\}/: Invalid escape 🤔

[ephemient]

nothing inside the [] character set needs to be escaped

[Shabinder Singh]

Thanks @ephemient this worked

"=function\\(\\w\\)\\{[a-z=.(\")]*;(.*);(?:.+)\\}"

Seems like time has come to learn regex myself 🙃

[Vampire]

I can recommend https://www.regular-expressions.info/ very much as a source for information and also about differences between the different dialects.

[Shabinder Singh]

https://kotlinlang.slack.com/archives/C3PQML5NU/p1681340732752949
Guys I am back need your help again, this time out of clue why jvm might be failing ?