Imported From: https://issues.scala-lang.org/browse/SI-8423?orig=1
Reporter: Martijn Hoekstra (martijn)

@adriaanm said:
I'm not sure I understand. The relevant sentence in the spec (https://github.com/adriaanm/scala-ref-markdown/blob/master/03-lexical-syntax.md#character-literals) is:

The character is either a printable unicode character or is described by an escape sequence.

This explicitly allows '\u000A' because it uses an escape sequence. Are you saying the Scala program

val c = '
'

is accepted somehow? I can't reproduce that interpretation

Martijn Hoekstra (martijn) said:
On the first issue:

Yes, you are right in that regard. It's the example in the spec itself that doesn't align with the spec, not the lexer. The example from the spec:

Example: some character literals

'a' '\u0041' '\n' '\t'
Note that '\u000A' is not a valid character literal because Unicode conversion is done before literal parsing and the Unicode character \u000A (line feed) is not a printable character. One can use instead the escape sequence '\n' or the octal escape '\12' (see here).

This is clearly talking about the unicode escape '\u000A' rather than the literal newline character (or it wouldn't talk about the actual Unicode conversion). This part of the spec is taken 1-1 from the Java spec.I haven't tried for any other non-printing characters.

With regards to the second bit: yes, I'm saying that the Scala program

val c = '
'

is accepted. Locally on my machine with Scala 2.10.3 Win7 as well as on scastie http://scastie.org/4645 at least. I'm not sure if this is a bug with the lexer or a bug with the spec.

Duplicates #6810 which amended the spec text.

I think the correction says that the character can't be a newline, but it can be a unicode newline or a normal escape char \n.