Please allow me to add my 2 cents. How I think about multi-line feature: it
should allow to paste any text as-is, which will have no any special
letters/symbols in it. Such text should be copied to variable *exactly* as
typed inside source file.
I want to be able to have in source file exactly this text, without any
wrapping of "disallowed" symbols :
<?xml version="1.0"?>
<catalog>
<book id="myid" empty="">
<author>myAuthor</author>
<title>myTitle \tutorial 1\(edition 2)</title>
</book>
</catalog>
(please note this "\tuttorial" and "\(edition" )
So, I suggest to start such multi line with "\ and have " as
end-of-multiline marker:
var xml = "\
<?xml version="1.0"?>
<catalog>
<book id="myid" empty="">
<author>myAuthor</author>
<title>myTitle \tutorial 1\(edition 2)</title>
</book>
</catalog>
"
Pros:
* text as-is, you can have " \ \\ \t \( etc symbols
* var xml = " - clearly seems like start of string, all the lines looks
like inside one string
* "\ - says that here is some special case, as we usually need some symbol
after \ to have special character like \t or \n
* ends with " - clearly see that here is an end of string (probably ";
should be required here.)
Cons:
* if we need tabs inside our 'xml' variable - we need to keep them in
source file
* spaces at the end of each line could be trimmed by editor
* line with only " symbol is not allowed inside mutli-line string - it will
terminate the string.
But the cons could be solved (if you need this) by custom markers you can
use to replace later in 'xml' variable like:
var multiline = "\
#tab<folder>
#tab#tab<file>...</file>
#tab#tab<file>...</file>
#tab</folder>
"
multiline.replace("#tab", to:"\t")
On 26.04.2016 8:53, Michael Peternell via swift-evolution wrote:
"""Just in my opinion: having to start each line with a particular token
kinda defeats the purpose of multiline string literals. "can't we just
continue" "the literal on the next line anyways," "like in C?" "or maybe
the "+ "at the end of the line can be"+ "optimized away?" """
What is wrong with just using """ as a delimiter? Except that maybe
there are other languages which use this already. You can copy&paste
whole XML snippets into such a thing. It's also good for usage
instructions in a command line tool, and I think everyone will
understand what it means. Is it a design goal to do something completely
new? Or are you just unhappy with all existing multi-line string literal
syntaxes?
>
-Michael (who would be happy with Perl Heredoc-Syntax as well)
Am 26.04.2016 um 01:00 schrieb ted van gaalen via swift-evolution
<swift-evolution@swift.org>:
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 <tedvgios...@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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