<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="">Thanks for the clarification. Why is the compiler saying that the catch is not exhaustive when it is covering all the possible values of the enum? Is it to be able to catch future values added to the enum type?<div class=""><br class=""></div><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Dec 18, 2015, at 8:05 PM, David Owens II <<a href="mailto:david@owensd.io" class="">david@owensd.io</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Dec 18, 2015, at 4:38 PM, Ricardo Parada <<a href="mailto:rparada@mac.com" class="">rparada@mac.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="content-type" content="text/html; charset=utf-8" class=""><div dir="auto" class=""><div class=""><div class=""><span style="background-color: rgba(255, 255, 255, 0);" class="">Hi David</span></div><div class=""><span style="background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div class=""><span style="background-color: rgba(255, 255, 255, 0);" class="">I started reading your proposal and I have a couple of questions. </span></div><div class=""><span style="background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div class=""><span style="background-color: rgba(255, 255, 255, 0);" class="">In the Enum Base ErrorType example you mentioned that it requires a "catch { }" clause. However the code is already covering the two possible Enum values (OffBy1 and MutatedValue). Why is the "catch { }" required? I typed that code into a playground and I did not get any errors. Are you saying that because the Enum type could add a value in the future?</span></div></div></div></div></blockquote><div class=""><br class=""></div><div class="">Playgrounds are basically in an anonymous function that throws, so the problem doesn’t show up there at the top level. Copy this into your playground.</div><div class=""><br class=""></div></div><blockquote style="margin: 0 0 0 40px; border: none; padding: 0px;" class=""><div class=""><div class=""><font face="Menlo" class="">enum MyError: ErrorType {</font></div></div><div class=""><div class=""><font face="Menlo" class=""> case OnlyOne</font></div></div><div class=""><div class=""><font face="Menlo" class="">}</font></div></div><div class=""><div class=""><font face="Menlo" class=""><br class=""></font></div></div><div class=""><div class=""><font face="Menlo" class="">func thrower() throws { throw MyError.OnlyOne }</font></div></div><div class=""><div class=""><font face="Menlo" class=""><br class=""></font></div></div><div class=""><div class=""><font face="Menlo" class="">func nolies() {</font></div></div><div class=""><div class=""><font face="Menlo" class=""> do {</font></div></div><div class=""><div class=""><font face="Menlo" class=""> try thrower()</font></div></div><div class=""><div class=""><font face="Menlo" class=""> }</font></div></div><div class=""><div class=""><font face="Menlo" class=""> catch MyError.OnlyOne { print("handled") }</font></div></div><div class=""><div class=""><font face="Menlo" class=""> // catch { print("compiler error until uncommented") }</font></div></div><div class=""><div class=""><font face="Menlo" class="">}</font></div></div></blockquote><div class=""><div class=""><br class=""></div><blockquote type="cite" class=""><div dir="auto" class=""><div class=""><div class=""><span style="background-color: rgba(255, 255, 255, 0);" class="">Also, you proposed the catch clause to use error as the name of the constant holding the error. Wouldn't it be better to let the programmer decide the name rather than hard coding it to use error? For example:</span></div><div class=""><span style="background-color: rgba(255, 255, 255, 0);" class=""><br class=""></span></div><div class=""><span style="background-color: rgba(255, 255, 255, 0);" class="">catch e where e.value == 0 { print("0") }</span></div><div class=""><div class=""><span style="background-color: rgba(255, 255, 255, 0);" class="">catch e where e.value == 1 { print("1") }</span></div><div class=""><span style="background-color: rgba(255, 255, 255, 0);" class="">catch { print("nothing") }</span></div></div></div></div></blockquote><div class=""><br class=""></div><div class="">The “error” name is already specified in the Swift rules for what the constant is. I don’t see any compelling reason to propose a change to that.</div><div class=""><br class=""></div><div class="">-David</div></div></div></div></blockquote></div><br class=""></div></body></html>