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<div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;">Regards</div><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;"><br class=""></div><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;">Letanyan Arumugam</div><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" class=""><br class=""></div><br class="Apple-interchange-newline">
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<div><br class=""><blockquote type="cite" class=""><div class="">On 07 Dec 2017, at 21:07, Chris Lattner <<a href="mailto:clattner@nondot.org" class="">clattner@nondot.org</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 7, 2017, at 7:15 AM, Letanyan Arumugam 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=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class=""><br class="Apple-interchange-newline">
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<div class=""><br class=""><blockquote type="cite" class=""><div class="">On 07 Dec 2017, at 17:02, Xiaodi Wu <<a href="mailto:xiaodi.wu@gmail.com" class="">xiaodi.wu@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class=""><br class=""><div class="gmail_quote"><div dir="auto" class="">On Thu, Dec 7, 2017 at 00:37 Letanyan Arumugam via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word;line-break:after-white-space" class=""><div class=""><br class=""><blockquote type="cite" class=""><div class=""><div 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" class=""><div class="">This seems marginally tolerable, but excessive.</div><div class=""><br class=""></div><div class="">Do we mark every usage of a type that can generate precondition failures or fatal errors for reasons other than “no such method?” No, we don’t.</div><div class=""><br class=""></div></div></div></blockquote></div></div><div style="word-wrap:break-word;line-break:after-white-space" class=""><div class=""><div class="">fatalError shouldn’t be used excessively. API surface areas for these types are going to be massive (infinite technically). I assume many people are going to be writing a lot of code would these types and calling many methods and properties which would all essentially have a fatalError. Would you consider it good code if the majority of all your types had methods defined with fatalError calls.</div></div></div></blockquote><div dir="auto" class=""><br class=""></div><div dir="auto" class="">What is the basis for this claim? Probably the majority of standard library methods check preconditions and trap on failure. That is how I write my code as well.</div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br class="">
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</div></blockquote><br class=""></div><div class="">I’m talking specifically about fatalError not precondition. fatalError is something that goes out with production code while precondition is used for debugging. I think you would agree a shipped program that has many states of being unrecoverable is not a good design?</div></div></div></blockquote><br class=""></div><div class="">You are aware that Int traps on overflow and arrays trap on out of bounds, right?</div><div class=""><br class=""></div></div></div></blockquote><br class=""></div><div>Were each of them not decided upon separately based on certain tradeoffs? Arrays for speed and Int overflow because having the addition operator return an optional would be too cumbersome? If these reasons were not so influential would they still be designed to trap?</div><br class=""></body></html>