<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Yes, in the sense that <a href="https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/Patterns.html#//apple_ref/doc/uid/TP40014097-CH36-ID423" class="">the grammar</a> has a production that permits the tuple element name. But there aren't any examples that use labels within patterns.<div class=""><br class=""></div><div class=""><br class=""></div><div class=""><section class="section" style="padding: 15px 25px 30px;"><div class="syntax-defs" style="border-width: 0px 0px 0px 5px; border-left-style: solid; border-left-color: rgb(233, 233, 233); font-size: 1.4em; margin: 20px 0px; outline: 0px; padding: 0px 0px 0px 15px; vertical-align: baseline; line-height: 20.299999237060547px;"><p class="syntax-defs-name" style="border: 0px; font-size: 0.63em; margin: 0px 0px 8px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(128, 128, 128); letter-spacing: 2px; text-transform: uppercase;">GRAMMAR OF A TUPLE PATTERN</p><div class="syntax-defs-group" style="border: 0px; font-size: 14px; margin: 0px 0px 12px; outline: 0px; padding: 0px; vertical-align: baseline;"><div style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;" class=""><a name="//apple_ref/swift/grammar/tuple-pattern" 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);" class=""></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;">tuple-pattern </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;">(</code><span class="optional" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;"><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/content/documentation/Swift/Conceptual/Swift_Programming_Language/Patterns.html#//apple_ref/swift/grammar/tuple-pattern-element-list" data-renderer-version="2" data-id="//apple_ref/swift/grammar/tuple-pattern-element-list" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(0, 136, 204); text-decoration: none;" class="">tuple-pattern-element-list</a></span><sub class="subscript" style="border: 0px; font-size: 0.8em; margin: 0px 0px 0px -2px; outline: 0px; padding: 0px 4px 0px 0px; color: rgb(128, 128, 128); font-style: italic;">opt</sub></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;">)</code></div><div style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;" class=""><a name="//apple_ref/swift/grammar/tuple-pattern-element-list" 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);" class=""></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;">tuple-pattern-element-list </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="alternative" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; display: inline;"><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/content/documentation/Swift/Conceptual/Swift_Programming_Language/Patterns.html#//apple_ref/swift/grammar/tuple-pattern-element" data-renderer-version="2" data-id="//apple_ref/swift/grammar/tuple-pattern-element" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(0, 136, 204); text-decoration: none;" class="">tuple-pattern-element</a> |</span> </span><span class="alternative" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; display: inline;"><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/content/documentation/Swift/Conceptual/Swift_Programming_Language/Patterns.html#//apple_ref/swift/grammar/tuple-pattern-element" data-renderer-version="2" data-id="//apple_ref/swift/grammar/tuple-pattern-element" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(0, 136, 204); text-decoration: none;" class="">tuple-pattern-element</a></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;">,</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/content/documentation/Swift/Conceptual/Swift_Programming_Language/Patterns.html#//apple_ref/swift/grammar/tuple-pattern-element-list" data-renderer-version="2" data-id="//apple_ref/swift/grammar/tuple-pattern-element-list" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(0, 136, 204); text-decoration: none;" class="">tuple-pattern-element-list</a></span></span></div><div style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;" class=""><a name="//apple_ref/swift/grammar/tuple-pattern-element" 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);" class=""></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;">tuple-pattern-element </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="alternative" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; display: inline;"><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/content/documentation/Swift/Conceptual/Swift_Programming_Language/Patterns.html#//apple_ref/swift/grammar/pattern" data-renderer-version="2" data-id="//apple_ref/swift/grammar/pattern" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(0, 136, 204); text-decoration: none;" class="">pattern</a> |</span> </span><span class="alternative" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; display: inline;"> <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/content/documentation/Swift/Conceptual/Swift_Programming_Language/LexicalStructure.html#//apple_ref/swift/grammar/identifier" data-renderer-version="2" data-id="//apple_ref/swift/grammar/identifier" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(0, 136, 204); text-decoration: none;" class="">identifier</a></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;">:</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/content/documentation/Swift/Conceptual/Swift_Programming_Language/Patterns.html#//apple_ref/swift/grammar/pattern" data-renderer-version="2" data-id="//apple_ref/swift/grammar/pattern" style="border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline; color: rgb(0, 136, 204); text-decoration: none;" class="">pattern</a></span></span></div></div></div></section><section class="section" style="padding: 15px 25px 30px;"><a name="//apple_ref/doc/uid/TP40014097-CH36-ID424" style="border: 0px; font-size: 10px; margin: -85px 0px 0px; outline: 0px; padding: 85px 0px 0px; vertical-align: baseline; display: block; width: 0px; height: 0px; color: rgb(0, 136, 204); font-family: Helvetica, Arial, sans-serif;" class=""></a></section></div><div class=""><br class=""></div><div class="">-Kyle<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Jun 15, 2017, at 10:34 AM, Chris Lattner 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=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">Is this capability even documented in TSPL?</span></div></blockquote></div><br class=""></div></body></html>