[emn13]

Having multiple almost identical ways of achieving things is a bug magnet in programming languages. Differing programmers will presumably use different styles (why else even support differences?), and if you mix code like that, bugs ensue. This a hassle not just because autoformatters are liable to make churny changes (which distract from real changes, which makes history harder to understand: bug magnet), but also because people will make mistakes e.g. when find-replacing (another minor bug magnet!). Then there's the fact that some of those quotes aren't symmetric - so you need to think of something to have happen when they're unpaired or used incorrectly, and it wouldn't surprise me if no matter what you did, you surprise somebody (bug magnet!).

Sure: these are all quibbles, and a language wouldn't die from all these minor cuts. But they're definitely downsides, not upsides. So: where is that upside? Why would you ever support something like this? "It looks a little nicer" sounds like a pretty weak argument compared to "it's inconsistent, hard to machine process, and may cause a few bugs"...

[samatman]

Many programming languages, certainly not all, offer single and double-quoted strings already. Which is, granted, a perennial source of annoyance for those of us trying to have a consistent formatting style.

I want «guillemet strings» because they use a matched pair, so you can «quote a string «within a string» without escaping» and I think that's a nice property.

I'm not really interested in supporting all the forms in which they're used in European languages, though, that would be a real hassle. Just the one that looks like the other matched pairs we use in programming.

“smart quotes” have ‟at least two styles” and really „three styles”, and the first two are really easy to confuse with "normal double-quotes". I don't want my users to have to deal with "why doesn't this compile”?, and if I allowed it to compile, now you have to escape all the quote characters inside any string, which is messy.

Raku, as a sibling points out, has bitten down on this bullet, and I respect that. I keep meaning to give it a spin, I'm fond of Parsing Expression Grammars and have good feelings about Perl from the early days.

[b2gills]

Those work in Raku, with the exception of ‟at least two styles”.

    .say for q[‟”].uninames
    # DOUBLE HIGH-REVERSED-9 QUOTATION MARK
    # RIGHT DOUBLE QUOTATION MARK

If you use one type of quote, you can use the others inside of it with no problem.

    “double "quotes"”

(Raku doesn't use a tokenizer.)

Also note that you can use a variety of characters for quoting if you use `q`, `qq` or `Q` etc.

    q<<<<1 < 2>>>>  eq  '1 < 2'  eq  q^1 < 2^  eq  q%1 < 2%  eq  q｢1 < 2｣

Note that many Unicode characters which have a LEFT and RIGHT variant will also be paired when you do that. q⦑like this⦒

In Raku string literals are actually a [parameterized domain specific language](https://docs.raku.org/language/quoting). (The domain of creating strings.)

    my $buffer = Blob.new(115,116,114,105,110,103); # 'string'.encode()

    Q            # start with raw quoting
    :scalar      # enable embedding the value of scalars
    :backslash   # enable backslashing characters
    [This is a $buffer.decode()\n]

There are shortcuts for common uses

    'single'  eq  q [single]  eq  Q :single [single]  eq  Q :q [single]
    ‘single’  eq  ‚single’

    "double"  eq  qq [double]  eq  Q :double [double]  eq  Q :qq [double]
    “double”  eq  „double”

    ｢raw｣   eq   Q [raw]

    < words >   eqv   qw [ words ]   eqv   q :words [ words ]

    << quote words >>   eqv   qqww [ quote words ]   eqv   Q :double :quotewords [ quote words ]
    « quote words »

This is not exhaustive.

:double is actually short for :scalar :array :hash :function :closure :backslash

:words splits on whitespace :quotewords splits on whitespace but respects quoted sections

    q      :words [ a "b c" ]   eqv   ( 'a', '"b', 'c"' )
    q :quotewords [ a "b c" ]   eqv   ( 'a', 'b c' )

Note that :double is the same as any adverb in the language, so you can negate a feature with :!double.

    qq [with newline\n]
    qq :!backslash [without newline\n]

    qq :!array [[e-mail]()]

(It's actually rather difficult to accidently use @ or % variables.)

[zzo38computer]

PostScript has something like the «guillemet strings», but it uses parentheses instead. The parentheses can be nested without escaping.