I still don't really see what's so wrong with just doing:
let foo = "This my " +
"multiline " +
"string"
It's only one or two characters more than other proposed styles, and IMO it's
not something that should come up all that often; I'm kind of uncomfortable
with the idea of encouraging multi-line strings in code, as really these should
be localised properly instead.
If there needs to be an alternative I'd say just allow omission of the
concatenation operator like so:
let foo = "This my "
"multiline "
"string"
The caveat for this is that we would need to disallow a string as a statement,
or require explicit concatenation anywhere it might be ambiguous like so:
let foo = "This my "
"multiline "
"string".capitalized // Warning: Use concatenation (+) or let _ = to
disambiguate
This would need become one of the following:
let foo = "This my "
"multiline " + // Clearly concatenated
"string".capitalized
let foo = "This my " +
"multiline "
let _ = "string".capitalized // Clearly separate for some reason
But yeah, I don't know if we should really encourage multi-line comments too
much; if I had my way we'd somehow make them more awkward to use, just to stop
people using them š
> On 3 Apr 2017, at 13:36, Adrian Zubarev via swift-evolution
> <[email protected]> wrote:
>
> I donāt really think this is about how to indicate a multi-lined string,
> where the string starts and ends with something like ", ' or """ is trivial
> to me. Itās just a decision to make. However the main debate I see with that
> topic is the ambiguity from the readers perspective.
>
> In your example I assume you want a result to match this: āmy multiline
> stringā, but what if you need precision? Should we really fallback to single
> line string then? What if you want to print some XML file with all itās
> indent calculated with whitespaces rather than tabs? The multiline version
> like that wonāt work, and if your string is huge youāll end up at a place
> where we already are. This doesnāt solve the main then because we could
> otherwise simply allow this today:
>
> let string = "my
> multiline
> string"
> Iām only speaking for my personal preference, others might see it completely
> different. However Iām totally sure multiline strings solve more than simply
> being able to write them so that the compiler is satisfied.
>
> As a compromise for everyone we possibly could come up with a way which
> serves both, simplicity and precision.
>
> For the next bikeshedding example Iām going to use ' for multi-lined strings:
>
> // Simplicity which supports indent but at a cost of no
> // leading or trailing space characters
> let string1 = 'my
> multiline
> string'
>
> print(string1) // prints "mymultilinestring"
>
> let string2 = 'my \
> multiline \
> string'
>
> // Trailing precision
> print(string2) // prints "my multiline string"
>
> let string3 = 'my
> ' multiline
> ' string'
>
> // Leading precision
> print(string3) // prints "my multiline string"
>
> let string4 = 'my \
> ' multiline \
> ' string'
>
> // Leading and trailing precision
> print(string4) // prints "my multiline string" (Note: 2x two whitespaces)
>
> let string5 = 'my\
> 'multiline\
> 'string'
>
> // Leading and trailing precision
> // Provide a fix-it to remove some `\` and `'` characters
> // because it equals `string1`
> print(string5) // prints "mymultilinestring"
>
> let string6 = 'my \
> 'multiline \
> 'string'
>
> // Leading and trailing precision
> // Provide a fix-it to remove some `'` characters
> // because it equals `string2`
> print(string6) // prints "my multiline string"
>
> let string7 = 'my\
> ' multiline\
> ' string'
>
> // Leading and trailing precision
> // Provide a fix-it to remove some `\` characters
> // because it equals `string3`
> print(string7) // prints "my multiline string"
> Comments should be only allowed after the escaping character. string1 can
> only have comments after the last line of that string.
>
> I think a model like this could have the best from both worlds.
>
> Personally I dislike the idea of """ and would rather want a model from above
> with " and \ or as written.
>
>
>
>
> --
> Adrian Zubarev
> Sent with Airmail
>
> Am 3. April 2017 um 11:56:12, Daniel Leping ([email protected]
> <mailto:[email protected]>) schrieb:
>
>> 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
>> <[email protected] <mailto:[email protected]>> wrote:
>> Simply because itās 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 donāt disagree that typing out some extra " and \ is tedious, but what I
>> really like about it is, itās 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 ([email protected]
>> <mailto:[email protected]>) 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
>>>> <[email protected] <mailto:[email protected]>>
>>>> wrote:
>>>>
>>>> This is almost the same as proposed, but we use " instead of |, however
>>>> you still donāt have trailing space characters covered like this.
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Adrian Zubarev
>>>> Sent with Airmail
>>>>
>>>> Am 3. April 2017 um 11:16:41, Charlie Monroe ([email protected]
>>>> <mailto:[email protected]>) 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
>>>>>> <[email protected]
>>>>>> <mailto:[email protected]>> wrote:
>>>>>>
>>>>>> My main concern with this approach is that you donāt have any control
>>>>>> about indent and you loose pre- and post spacing characters.
>>>>>>
>>>>>> A concatenating approach is a little tedious but itās 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 isnāt that harmful.
>>>>>> ;-)
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Adrian Zubarev
>>>>>> Sent with Airmail
>>>>>>
>>>>>> Am 3. April 2017 um 10:49:02, Charlie Monroe ([email protected]
>>>>>> <mailto:[email protected]>) 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
>>>>>>>> <[email protected] <mailto:[email protected]>> wrote:
>>>>>>>>
>>>>>>>> Hello Swift community,
>>>>>>>>
>>>>>>>> on Github there is a PR for this proposal, but I couldnāt find any up
>>>>>>>> to date thread, so Iām 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 ā' 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 ā"ā.
>>>>>>>>
>>>>>>>> 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
>>>>>>>>
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> swift-evolution mailing list
>>>>>>>> [email protected] <mailto:[email protected]>
>>>>>>>> https://lists.swift.org/mailman/listinfo/swift-evolution
>>>>>>>> <https://lists.swift.org/mailman/listinfo/swift-evolution>
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>
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>
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