<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Feb 7, 2016, at 8:29 PM, Steve Richey via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii" class="">
<div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; font-size: 14px; font-family: Calibri, sans-serif;" class="">
<div class="">It is not uncommon to want to run code at build time. Xcode solves this need by allowing "Build Phases", which are often shell scripts which handle compile-time tasks.</div>
<div class=""><br class="">
</div>
<div class="">It may be beneficial to Swift developers, especially those who are not programming on platforms supported by Xcode, to handle compile-time tasks in a powerful and expressive language with which they are already familiar: Swift!</div>
<div class=""><br class="">
</div>
<div class="">In short, I propose the addition of a `#run` expression that allows the execution of code at compile time. This syntax and concept are borrowed from the programming language Jai (<a href="https://sites.google.com/site/jailanguageprimer/#TOC-Arbitrary-Compile-Time-Code-Execution" class="">https://sites.google.com/site/jailanguageprimer/#TOC-Arbitrary-Compile-Time-Code-Execution</a>)
but the syntax fits nicely with other special expression syntax in Swift such as `#available`, `#selector`, `#file`, and so on.</div></div></div></blockquote><div><br class=""></div><div>Something like this would definitely be interesting to build out. We should investigate it post-Swift 3 in the context of a hygienic macro system.</div><div><br class=""></div><div>-Chris</div><div><br class=""></div></div></body></html>