string.split('\n') not working

[johanatan]

Scala REPL:

Jonathans-MacBook-Pro:~ jonathan$ scala
Welcome to Scala version 2.11.1 (Java HotSpot(TM) 64-Bit Server VM, Java 1.7.0_45).
Type in expressions to have them evaluated.
Type :help for more information.

scala> val string = "blah\nblah\nblah\nblah"
string: String =
blah
blah
blah
blah

scala> assert(string.split('\n').length == 4)

scala> assert(string.split('\n').length == 3)
java.lang.AssertionError: assertion failed
  at scala.Predef$.assert(Predef.scala:151)
  ... 32 elided

Scala JS:

def main(): Unit = {
  val string = "blah\nblah\nblah\nblah"
  assert(string.split('\n').length == 4)
}

=>
Uncaught java.lang.AssertionError: assertion failed

[sjrd]

Quick note: a workaround is to use .split("\n") instead (with the string "\n" rather than the character '\n').

[sjrd]

That would be an instance of the limitations on Regular Expressions documented here:
http://www.scala-js.org/doc/semantics.html
The implementation of StringLike.split(Char) uses the same escape sequences \Q and \E as StringLike.split(Array[Char]), which JavaScript regexps do not support.

[johanatan]

It's an implementation detail of StringLike.split(Char) that regular expressions are involved. One wouldn't know that (or expect it) from its type signature.

[lihaoyi]

Well it's the way it works in Java too, and it's what it says in the docs,
and tutorials, so...

On Thu, Jul 24, 2014 at 3:24 PM, Jonathan Leonard notifications@github.com
wrote:

It's an implementation detail of StringLike.split(Char) that regular
expressions are involved. One wouldn't know that (or expect it) from its
type signature.

—
Reply to this email directly or view it on GitHub
#872 (comment).

[lihaoyi]

Unless I'm missing something (maybe I'm confused, but I've bumped into
something like this in Java before too, and got equally confused, so maybe
I'm confused now too)

EDIT: It looks like I was confused, please ignore me, sorry

On Thu, Jul 24, 2014 at 3:27 PM, Haoyi Li haoyi.sg@gmail.com wrote:

Well it's the way it works in Java too, and it's what it says in the docs,
and tutorials, so...

On Thu, Jul 24, 2014 at 3:24 PM, Jonathan Leonard <
notifications@github.com> wrote:

It's an implementation detail of StringLike.split(Char) that regular
expressions are involved. One wouldn't know that (or expect it) from its
type signature.

—
Reply to this email directly or view it on GitHub
#872 (comment).

[sjrd]

I know. My second comment was more intended for us (the developers) as a reminder of the root cause of the issue, or that we have to document it. I'm sorry if that was not clear.

[johanatan]

@sjrd Oh, no problem. Just wanted to make sure we're on the same page. After reading issue #105 it is clear now. Thanks! [Also, it seems from that discussion that this particular manifestation of the bug is a regression as StringLike.split(Char) was once hailed as an example where it worked as advertised]. :)

[sjrd]

Ah ah! Good point! It seems e554140 was not sufficient as a fix for #65: it does not account for \n and other control characters.
We'll fix that in the next release.

[sjrd]

Fixed in b6a3075