<div dir="ltr">Sorry about the lack of a subject on this message originally. I was replying to the email digest and forgot to add one. It should be part of the "multi-line string literals" thread.<div><br></div><div>-John<br><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Dec 11, 2015 at 11:52 AM, John Siracusa <span dir="ltr"><<a href="mailto:siracusa@gmail.com" target="_blank">siracusa@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr"><div><br></div><div>Chris Lattner wrote:</div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">When introducing a feature like this, I think it would be useful to survey a range of popular languages (and yes, even perl ;-) to understand what facilities they provide and why (i.e. what problems they are solving) and synthesize a good swift design that can solve the same problems with a hopefully simple approach.</blockquote><div><br></div><div>Travis Tilley wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">Perl and Erlang are unique in that valid code in either language looks essentially like line noise. I'd rather take inspiration from languages like ruby, python, and elixir.</blockquote><div><br></div><div><div>Jokes aside, the ability to choose delimiters for strings and other language constructs that surround some value is a huge boon to code readability.</div><div><br></div><div>For example, RegExp literals in JavaScript:</div><div><br></div><div>var regex = /^\/usr\/local\//; // gross</div><div><br></div><div>An even simpler example, which applies to many languages: a string literal that contains all of your possible string delimiters within it. This is not an exotic thing in English.</div><div><br></div><div>message = "\"I don't like this,\" she said."; // nope</div><div>message = '"I don\'t like this," she said.'; // still nope</div><div><br></div><div>Then, of course, there's your escape character itself:</div><div><br></div><div>escapes = "Some escapes: \\n, \\t, \\a"; // sigh</div><div><br></div><div>There are many time-tested solutions to these syntactic/cosmetic problems. </div><div><br></div><div>* Different delimiters with different interpolation rules (e.g., single quotes not honoring any backslash escapes and not doing variable interpolation)</div><div><br></div><div>* Matched-pair delimiters that don't require anything to be escaped as long as the delimiters are absent or matched within the string. (These alone solve a huge range of problems.)</div><div><br></div><div>* Heredocs for long literals where you get to pick the end token.</div><div><br></div><div>* Heredocs modified by delimiters around the end token to control interpolation within the long literal.</div><div><br></div><div>Which language looks like line noise now?</div><div><br></div><div><span style="white-space:pre-wrap"> </span>$messasge = q("I can't believe how nice this is," she said (quietly).);</div><div><br></div><div><span style="white-space:pre-wrap"> </span>$regex = qr(^/usr/local/);</div><div><br></div><div><span style="white-space:pre-wrap"> </span>$escapes = 'Some escapes: \n, \t, \a';</div><div><br></div><div>My take: once you use a language where you pretty much never have to backslash-escape a character you can easily type to get it into a string, it's really hard to go back. </div><span class=""><font color="#888888"><div><br></div><div>-John</div></font></span></div><div><br></div></div>
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