<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=""><br class=""><div><blockquote type="cite" class=""><div class="">On Dec 15, 2015, at 4:53 PM, Vester Gottfried via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:</div><div class=""><div dir="ltr" class=""><font face="monospace, monospace" class=""><br class=""></font></div></div></blockquote><snip></div><div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><font face="monospace, monospace" class="">My proposal would be to make the else block optional and define a default behaviour.<br class=""><br class="">For example:<br class=""><br class="">func foo(x: Int) {<br class=""><div class="gmail_default" style="font-family:monospace,monospace;display:inline"> </div>guard x < 10<br class=""><div class="gmail_default" style="font-family:monospace,monospace;display:inline"> </div>...<br class="">}<br class=""><br class="">swift would implicitly add "else { return }”<br class=""><br class=""></font></div></div></blockquote><div><br class=""></div>That makes sense</div><div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><font face="monospace, monospace" class="">--<br class=""><br class="">func foo(x: Int) -> Int? {<br class=""><div class="gmail_default" style="font-family:monospace,monospace;display:inline"> </div>guard x < 10<br class=""><div class="gmail_default" style="font-family:monospace,monospace;display:inline"> </div>…<br class="">}<br class=""><br class=""></font></div></div></blockquote><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><font face="monospace, monospace" class="">swift would implicitly add "else { return nil }”<br class=""><br class=""></font></div></div></blockquote>You would need to decide how this plays into the type system </div><div>- is Optional a special case</div><div>- or, will it work with anything NilLiteralConvertible (Optional, ImplicitlyUnwrappedOptional, Pointer types, Selectors)</div><div><br class=""></div><div>I thought of using the no-argument initializer, but that creates too much default behavior (empty arrays, zero doubles, etc). </div><div><br class=""></div><div>Plus, it is inconsistent with variable declarations, which require explicit initialization before use.</div><div><br class=""></div><div><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><font face="monospace, monospace" class="">--<br class=""><br class="">for i in 0..<10 {<br class=""><div class="gmail_default" style="font-family:monospace,monospace;display:inline"> </div>guard i%2 == 0<br class="">}</font></div></div></blockquote><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><font face="monospace, monospace" class="">swift would implicitly add "else { continue }”</font></div></div></blockquote><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><font face="monospace, monospace" class="">switch {</font></div></div></blockquote><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><font face="monospace, monospace" class="">case a :<br class=""><div class="gmail_default" style="font-family:monospace,monospace;display:inline"> </div>guard x != y<br class="">case b :</font><div class=""><font face="monospace, monospace" class=""><div class="gmail_default" style="font-family:monospace,monospace;display:inline"> ...</div><br class="">}</font></div></div></div></blockquote><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class=""><span style="font-family: monospace, monospace;" class="">swift would implicitly add "else { break }"</span></div></div></div></blockquote><div><br class=""></div><div>-1 . Flow control functions need to be explicit, else I risk having (and assuming) the wrong behavior when I copy and paste code from one context to another.</div><div><br class=""></div><div>Plus, why would I expect a guard in a for loop to break or continue as a default behavior? I personally know I would constantly think this guard as ‘does what I mean’, while in the debugger it seems to be doing exactly the opposite of what I assumed, every time, regardless of my assumption ;-)</div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class=""><font face="monospace, monospace" class=""><br class="">func foo(x: Int) -> Int {<br class=""><div class="gmail_default" style="font-family:monospace,monospace;display:inline"> </div>guard x < 10<br class=""><div class="gmail_default" style="font-family:monospace,monospace;display:inline"> </div>...<br class="">}<br class=""><br class="">swift would provide a warning that the guard statement needs an else block<br class=""></font></div></div></div></blockquote><div><br class=""></div>Iff your proposal was to call the no-argument initializer, this would return 0. For the other options this would need to return an error, not a warning. </div><div><br class=""></div><div>-DW</div></body></html>