[swift-evolution] multi-line string literals.

Mon Apr 25 18:00:12 CDT 2016

possible improvement, one could allow
leading spaces before the "data line token"
thus enabling indentation, like so
{
       let str =
          \\dataaaaaaaaaahgdfhhfdxfg cvcsffggcfg
          \\c jggjvhfh fhffhfgxfxgdgfhgj  jvhhfhfhcgxgc
        .
        .
}

TedvG

> On 25 Apr 2016, at 20:47, Ted F.A. van Gaalen <tedvgiosdev at gmail.com> wrote:
> 
> This could be a simple solution: 
> 
> Starting each line with a special token.
> 
> In the example here it is the \\  double-backslash .  
> when the \\ appears in the first two columns of a source line, 
> this tells the compiler that it is a data line and that more might follow.
> the last line starting with \\ completes the data entry.
> 
> Here is an example of a string declaration with some XML
> (no escape sequences needed for “) 
> Of course it could be anything other kind of textual data as well.
> 
> let  str =  
> \\<!DOCTYPE html>
> \\<html>
> \\<body>
> \\
> \\<h1>W3Schools Internal Note</h1>\n
> \\<div>
> \\<b>To:</b> <span id="to"></span><br>\n
> \\<b>From:</b> <span id="from"></span><br>\n
> \\<b>Message:</b> <span id="message"></span>
> \\</div>
> \\\n
> \\<script>
> \\var txt, parser, xmlDoc;
> \\txt = "<note>" +
> \\"<to>Tove</to>" +
> \\etc. this is the last data line.
> 
> 
> Conditions: 
> 
> - Every line starting with \\ in first and second column of the line 
>   is  treated as a data line.
> - All characters behind the \\ are regarded as data, thus note that:
>      - the “ is not regarded as a string delimiter
>      - the // chars and whatever follows it are interpreted as data on such a line, not as comment.
>      -  \\  within the data itself are treated as data e.g. this line is valid:
> \\There \\ are three backslashes (as data) in this line \\\\ today.
> \\
> the above data line is empty but is allowed. 
> 
> - Leading and embedded spaces are respected.
> - Tabs, Linefeeds etc. can be inserted the usual way using \t \n etc. 
> - trailing spaces and line terminators cr lf are ignored, filtered out.
> 
> let dutchNumbers =            
> \\ een twee drie vier vijf
> 
> \\ zes zeven acht negen tien   
> \\these two data lines are orphans,
> 
> Blank lines or other Swift statement lines in-between
> breaks a set of \\ data lines 
> 
> 
> All \\ lines together are treated as one single string literal
> and may occur everywhere where “normal” string literals are allowed.
> 
>     // E.g. this if statement would be correct:
>     // Yes, this would be legal but doesn’t look so great: Indentation not possible here
>        if cars == 
> \\Ford
> \\ Delorean
> \\ Chevrolet
>       {
>           doSomething()
>       }
> 
> An array with 2 string elements: 
> 
> var ar =
> [ 
> \\sdkdslkdslkdsldkshfkjdljfsdljkfdshjklfd dioioioioio \n\nsljkf sdflkf dsl;dfsk sdlfk dfsfkds 
> \\ sdkdfkdfldkfd fdfldk   fdlkfd jkfds  hjklfd dsljkf sdflkf dsl;dfsk sdlfk dfsfkds 
> ,
> \\There are many ships in the ha
> \\rbour that are soon sailing away.
> ]
> 
> 
> I also thought about using “”  as token, but this would be interpreted as an empty string.
> or “”” but this is an empty string followed by an unclosed string literal.
> 
> Should be relatively easy to implement? What y’all think?
> 
> 
> Kind Regards
> TedvG
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