[swift-evolution] multi-line string literals.
Daniel Leping
daniel at crossroadlabs.xyz
Mon Apr 3 04:55:59 CDT 2017
What about """ notation?
It could become something like:
let mys = """my
multiline
string"""
On Mon, 3 Apr 2017 at 12:35 Adrian Zubarev via swift-evolution <
swift-evolution at swift.org> wrote:
> Simply because it’s always a zero to n space characters at the start of
> the line and at its end. You cannot predict the need of every multi-line
> string.
>
> I don’t disagree that typing out some extra " and \ is tedious, but what
> I really like about it is, it’s precise.
>
> let string =
> "Hello \ // Three trailing space characters
> "Swift\
> " 4.0" // Three leading space characters
>
> print(string) // prints: "Hello___Swift___4.0" where _ ist a space character
>
>
>
> --
> Adrian Zubarev
> Sent with Airmail
>
> Am 3. April 2017 um 11:27:58, Charlie Monroe (charlie at charliemonroe.net)
> schrieb:
>
> Yes, but with ", you need to escape " occurrences - which is a fairly
> common character - I'd say more common than |.
>
> The trailing whitespace - why can't it just be included in the string
> automatically? Just for supporting comments?
>
> On Apr 3, 2017, at 11:19 AM, Adrian Zubarev <
> adrian.zubarev at devandartist.com> wrote:
>
> This is almost the same as proposed, but we use " instead of |, however
> you still don’t have trailing space characters covered like this.
>
>
>
> --
> Adrian Zubarev
> Sent with Airmail
>
> Am 3. April 2017 um 11:16:41, Charlie Monroe (charlie at charliemonroe.net)
> schrieb:
>
> You can. I wish I remembered the language this was in (not sure if it's in
> Scala), but you can do something like:
>
> let xml = '''
> |<?xml version="1.0"?>
> |<catalog>
> | <...>
> |</catalog>
> '''
>
> This way, if you care about the leading whitespace, you define the line
> beginning using "|".
>
> Two characters aren't harmful, but in my experience when working with HTML
> strings, etc. the quote-escaping is extremely tedious.
>
> On Apr 3, 2017, at 11:06 AM, Adrian Zubarev <
> adrian.zubarev at devandartist.com> wrote:
>
> My main concern with this approach is that you don’t have any control
> about indent and you loose pre- and post spacing characters.
>
> A concatenating approach is a little tedious but it’s precise. In any
> situation a multi-lined string is not softly wrapped string, which implies
> that you will have to press enter for each new line you wish to have. IMHO
> adding two more characters for each line isn’t that harmful. ;-)
>
>
>
> --
> Adrian Zubarev
> Sent with Airmail
>
> Am 3. April 2017 um 10:49:02, Charlie Monroe (charlie at charliemonroe.net)
> schrieb:
>
> While I long for multiline string literals, I'd also very like to see a
> different syntax as in many cases, these can be XML/HTML snippets and the
> use of quotes is ubiqituous. I'd very much like to see a variant where you
> can simply paste almost any string without escaping it.
>
> For example, Scala uses a tripple-quote syntax... As we've gotten rid of '
> for character literals, we could use it for multiline strings?
>
> Or possibly tripple-apostrophe for multiline strings?
>
> let xml = '''
> <?xml version="1.0"?>
> <catalog/>
> '''
>
>
> On Apr 3, 2017, at 9:01 AM, Adrian Zubarev via swift-evolution <
> swift-evolution at swift.org> wrote:
>
> Hello Swift community,
>
> on Github there is a PR for this proposal, but I couldn’t find any up to
> date thread, so I’m going to start by replying to the last message I found,
> without the last content.
>
> I really like where this proposal is going, and my personal preference are
> *continuation quotes*. However the proposed solution is still not perfect
> enough for me, because it still lacks of precise control about the trailing
> space characters in each line of a multi-line string.
>
> Proposed version looks like this:
>
> let xml = "<?xml version=\"1.0\"?>
> "<catalog>
> " <book id=\"bk101\" empty=\"\">
> " <author>\(author)</author>
> " <title>XML Developer's Guide</title>
> " <genre>Computer</genre>
> " <price>44.95</price>
> " <publish_date>2000-10-01</publish_date>
> " <description>An in-depth look at creating applications with XML.</description>
> " </book>
> "</catalog>
> ""
>
> I would like to pitch an enhancement to fix the last tiny part by adding
> the escaping character ‘' to the end of each line from 1 to (n - 1) of the
> n-lined string. This is similar to what Javascript allows us to do, except
> that we also have precise control about the leading space character through
> ’"’.
>
> The proposed version will become this:
>
> let xml = "<?xml version=\"1.0\"?>\
> "<catalog>\ // If you need you can comment here
> " <book id=\"bk101\" empty=\"\">\
> " <author>\(author)</author>\
> " <title>XML Developer's Guide</title>\
> " <genre>Computer</genre>\
> " <price>44.95</price>\
> " <publish_date>2000-10-01</publish_date>\
> " <description>An in-depth look at creating applications with XML.</description>\
> " </book>\
> "</catalog>\
> ""
>
> Here is another example:
>
> let multilineString: String = "123__456__\ // indicates there is another part of the string on the next line
> "__789_____\ // aways starts with `"` and ends with either `\` or `"`
> "_____0_" // precise control about pre- and post-space-characters
>
> let otherString = "\(someInstance)\ /* only comments are allowed in between */ "text \(someOtherInstance) text"
>
> This is simply *continuation quotes* combined with *backslash
> concatenation*.
>
>
>
>
> --
> Adrian Zubarev
> Sent with Airmail
>
>
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