Regular expression checking doesn't work with string anchors

[jclem]

In ScalaFiddle, this is None (see https://scalafiddle.io/sf/amxlC9O/0):

"""\Ahello""".r.findFirstIn("hello")

In Scastie, it's Some(hello): https://scastie.scala-lang.org/ZUmFJMFgSNaGA2nrRXrUkA

[ochrons]

Scala.js uses JS regex engine, so it's not the same as on JVM.

[jclem]

Oh whoops, I didn't realize that ScalaFiddle uses Scala.js.

[ochrons]

There aren't many things that work differently from JVM, but regexes are one of them (for performance reasons) :)