<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="">On Apr 20, 2016, at 9:46 AM, BJ Homer via swift-evolution &lt;<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>&gt; wrote:<br class=""><div><blockquote type="cite" class=""><br class="Apple-interchange-newline"><div class=""><div class="">How would this proposal affect curried functions? Would this:<br class=""><br class=""> &nbsp;func foo(int: Int) -&gt; Int -&gt; String -&gt; String<br class=""><br class="">become this?<br class=""><br class=""> &nbsp;func foo(int: Int) -&gt; (((Int) -&gt; String) -&gt; String)<br class=""><br class="">As I understand, that transformation is an accurate representation of the actual return type of “foo”, but it’s certainly going to raise some complaints among the functional Swift community if required.<br class=""><br class="">-BJ<br class=""></div></div></blockquote></div><br class=""><div class="">To the best of my understanding, either:</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">func</span><span style="font-variant-ligatures: no-common-ligatures" class=""> foo(i: </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span><span style="font-variant-ligatures: no-common-ligatures" class="">) -&gt; (j: </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span><span style="font-variant-ligatures: no-common-ligatures" class="">) -&gt; (s: </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">String</span><span style="font-variant-ligatures: no-common-ligatures" class="">) -&gt; </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">String</span><span style="font-variant-ligatures: no-common-ligatures" class=""> { ...</span><span style="white-space: pre-wrap;" class="">&nbsp;</span><span style="white-space: pre-wrap;" class="">}</span></div><pre class="declaration" style="font-size: 8px; margin-top: 0px; margin-bottom: 0px; white-space: pre-wrap;"><div style="margin: 0px; font-size: 14px; line-height: normal; font-family: Menlo; color: rgb(0, 132, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> x = </span><span style="font-variant-ligatures: no-common-ligatures; color: #31595d" class="">foo</span><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> </span><span style="font-variant-ligatures: no-common-ligatures" class="">// let x: (Int) -&gt; (j: Int) -&gt; (s: String) -&gt; String</span></div></pre><div style="font-size: 10px;" class=""><div style="margin: 0px; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> a = </span><span style="font-variant-ligatures: no-common-ligatures; color: #31595d" class="">x</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #272ad8" class="">2</span><span style="font-variant-ligatures: no-common-ligatures" class="">); </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> b = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">a</span><span style="font-variant-ligatures: no-common-ligatures" class="">(j: </span><span style="font-variant-ligatures: no-common-ligatures; color: #272ad8" class="">3</span><span style="font-variant-ligatures: no-common-ligatures" class="">); </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> c = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">b</span><span style="font-variant-ligatures: no-common-ligatures" class="">(s: </span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"glob"</span><span style="font-variant-ligatures: no-common-ligatures" class="">); </span><span style="font-variant-ligatures: no-common-ligatures; color: #3d1d81" class="">print</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">c</span><span style="font-variant-ligatures: no-common-ligatures" class="">)</span></div></div></div><div style="margin: 0px; font-size: 18px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><br class=""></span></div><div class="">or</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">func</span><span style="font-variant-ligatures: no-common-ligatures" class=""> blort(i: </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span><span style="font-variant-ligatures: no-common-ligatures" class="">) -&gt; (</span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span><span style="font-variant-ligatures: no-common-ligatures" class="">) -&gt; (</span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">String</span><span style="font-variant-ligatures: no-common-ligatures" class="">) -&gt; </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">String</span></div></div><div style="margin: 0px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class=""><div style="margin: 0px; line-height: normal; color: rgb(0, 132, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> z = </span><span style="font-variant-ligatures: no-common-ligatures; color: #31595d" class="">blort</span><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> </span><span style="font-variant-ligatures: no-common-ligatures" class="">// let z: (Int) -&gt; (Int) -&gt; (String) -&gt; String</span></div></span></div><div style="margin: 0px; font-size: 18px; line-height: normal; font-family: Menlo;" class=""><div style="margin: 0px; line-height: normal; font-size: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> aa = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">z</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #272ad8" class="">2</span><span style="font-variant-ligatures: no-common-ligatures" class="">); </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> bb = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">aa</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #272ad8" class="">3</span><span style="font-variant-ligatures: no-common-ligatures" class="">); </span><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures" class=""> cc = </span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">bb</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #d12f1b" class="">"glob"</span><span style="font-variant-ligatures: no-common-ligatures" class="">); </span><span style="font-variant-ligatures: no-common-ligatures; color: #3d1d81" class="">print</span><span style="font-variant-ligatures: no-common-ligatures" class="">(</span><span style="font-variant-ligatures: no-common-ligatures; color: #4f8187" class="">cc</span><span style="font-variant-ligatures: no-common-ligatures" class="">)</span></div><div style="margin: 0px; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><br class=""></span></div></div><div class="">would still work (although x(2) would become x(i: 2) because of the new first label rules) vs the following which currently works but would not after adoption:</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">func</span><span style="font-variant-ligatures: no-common-ligatures" class=""> bar(i: </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span><span style="font-variant-ligatures: no-common-ligatures" class="">) -&gt; </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">Int</span><span style="font-variant-ligatures: no-common-ligatures" class=""> -&gt; </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">String</span><span style="font-variant-ligatures: no-common-ligatures" class=""> -&gt; </span><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class="">String { ... }</span></div></div><div style="margin: 0px; font-size: 18px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #703daa" class=""><div style="margin: 0px; line-height: normal; color: rgb(0, 132, 0); font-size: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #bb2ca2" class="">let</span><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> y = </span><span style="font-variant-ligatures: no-common-ligatures; color: #31595d" class="">bar</span><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> </span><span style="font-variant-ligatures: no-common-ligatures" class="">// let y: (Int) -&gt; Int -&gt; String -&gt; String</span></div><div style="margin: 0px; line-height: normal; color: rgb(0, 132, 0);" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><div style="color: rgb(0, 0, 0); font-family: Palatino; font-size: 14px;" class=""><br class=""></div><div style="color: rgb(0, 0, 0); font-family: Palatino; font-size: 14px;" class="">-- E, who is often wrong</div></span></div></span></div></body></html>