New long strings [was New long comments in 5.1]

[Roberto Ierusalimschy <roberto@...>]

> And don't forget the discussion isn't about long comments alone (even if 
> that's the subject of the thread), but also for long strings, which use 
> a similar syntax.

Actually, our proposal is for long strings, which happens to be used
for long comments, too. It does not make sense to discuss it in the
context of comments. (I am myself very happy with one-line comments.)
We have two small requirements:

- to be able to express any literal string;
- to be (as much as possible) an extension to the old [[...]], so that
we have compatibility without having two different long-string syntaxes.

-- Roberto