<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Swift Evolution SE-0028 (<a href="https://github.com/apple/swift-evolution/blob/master/proposals/0028-modernizing-debug-identifiers.md" class="">https://github.com/apple/swift-evolution/blob/master/proposals/0028-modernizing-debug-identifiers.md</a>) overloads<div class="">the use of #line to mean both an identifier that maps to a calling site's line number with a file and acts as part of a line control statement with the following grammar:<br class=""><div class=""><br class=""><div class=""><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; font-family: Helvetica, Arial, sans-serif;"><span class="syntax-def-name" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(128, 128, 128); font-style: italic;">line-control-statement </span><span class="arrow" style="border: 0px; margin: 0px; outline: 0px; padding: 0px 0px 0px 4px; vertical-align: baseline; color: rgb(128, 128, 128);">→ </span><code class="literal" style="border: 0px; font-size: 0.86em; margin: 0px; outline: 0px; padding: 0px 4px; vertical-align: baseline; font-family: Menlo, monospace; font-weight: 600; word-wrap: break-word;">#line</code></div><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; font-family: Helvetica, Arial, sans-serif;"><a name="//apple_ref/doc/uid/TP40014097-CH38-NoLink_926" class="" style="border: 0px; margin: -85px 0px 0px; outline: 0px; padding: 85px 0px 0px; vertical-align: baseline; display: block; width: 0px; height: 0px; color: rgb(0, 136, 204);"></a><span class="syntax-def-name" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(128, 128, 128); font-style: italic;">line-control-statement </span><span class="arrow" style="border: 0px; margin: 0px; outline: 0px; padding: 0px 0px 0px 4px; vertical-align: baseline; color: rgb(128, 128, 128);">→ </span><code class="literal" style="border: 0px; font-size: 0.86em; margin: 0px; outline: 0px; padding: 0px 4px; vertical-align: baseline; font-family: Menlo, monospace; font-weight: 600; word-wrap: break-word;">#line</code><span class="syntactic-cat" style="border: 0px; margin: 0px; outline: 0px; padding: 0px 4px; vertical-align: baseline; font-style: italic; word-break: keep-all;"><a href="https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Statements.html#//apple_ref/swift/grammar/line-number" data-renderer-version="2" data-id="//apple_ref/swift/grammar/line-number" class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(0, 136, 204); text-decoration: none;">line-number</a></span><span class="syntactic-cat" style="border: 0px; margin: 0px; outline: 0px; padding: 0px 4px; vertical-align: baseline; font-style: italic; word-break: keep-all;"><a href="https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/Statements.html#//apple_ref/swift/grammar/file-name" data-renderer-version="2" data-id="//apple_ref/swift/grammar/file-name" class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(0, 136, 204); text-decoration: none;">file-name</a></span></div><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; font-family: Helvetica, Arial, sans-serif;"><a name="//apple_ref/doc/uid/TP40014097-CH38-NoLink_927" class="" style="border: 0px; margin: -85px 0px 0px; outline: 0px; padding: 85px 0px 0px; vertical-align: baseline; display: block; width: 0px; height: 0px; color: rgb(0, 136, 204);"></a><span class="syntax-def-name" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(128, 128, 128); font-style: italic;">line-number </span><span class="arrow" style="border: 0px; margin: 0px; outline: 0px; padding: 0px 0px 0px 4px; vertical-align: baseline; color: rgb(128, 128, 128);">→ </span><span class="text-description" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;">A decimal integer greater than zero</span></div><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; font-family: Helvetica, Arial, sans-serif;"><a name="//apple_ref/doc/uid/TP40014097-CH38-NoLink_928" class="" style="border: 0px; margin: -85px 0px 0px; outline: 0px; padding: 85px 0px 0px; vertical-align: baseline; display: block; width: 0px; height: 0px; color: rgb(0, 136, 204);"></a><span class="syntax-def-name" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(128, 128, 128); font-style: italic;">file-name </span><span class="arrow" style="border: 0px; margin: 0px; outline: 0px; padding: 0px 0px 0px 4px; vertical-align: baseline; color: rgb(128, 128, 128);">→ </span><span class="syntactic-cat" style="border: 0px; margin: 0px; outline: 0px; padding: 0px 4px; vertical-align: baseline; font-style: italic; word-break: keep-all;"><a href="https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/LexicalStructure.html#//apple_ref/swift/grammar/static-string-literal" data-renderer-version="2" data-id="//apple_ref/swift/grammar/static-string-literal" class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(0, 136, 204); text-decoration: none;">static-string-literal</a></span></div></div></div></div><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; font-family: Helvetica, Arial, sans-serif;"><br class=""></div><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;">The accepted implementation of SE-0028 disambiguates the two by requiring #line (the control statement) to appear at the first column for the time being. This is a stop-gap solution best remedied by renaming #line. </div><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;"><br class=""></div><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;">Chris Lattner writes, "The core team isn’t thrilled with the magic “first token on a line” whitespace behavior that #line will be getting, and would like someone to start a discussion about renaming the old #line directive to something more specific and tailored to its purpose. Once that name and syntax is settled, we can rename the directive and remove the whitespace rule."</div><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;"><br class=""></div><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;">I'd recommend <font face="Menlo" class="">#setline</font> or <font face="Menlo" class="">#linenumber</font>. Starting this thread to solicit other suggestions.</div><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;"><br class=""></div><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;">Best, -- E</div><div class="" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;"><br class=""></div></body></html>