<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=""><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="">What about calling a framework variadic function that I could not re-declare?</div><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">like print</div><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class=""><br class=""><blockquote type="cite" class=""><div class="">在 2017年12月2日，上午1:26，Tino Heth <<a href="mailto:2th@gmx.de" class="">2th@gmx.de</a>> 写道：</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="">There has been a solution to the same problem that’s imho much nicer, because instead of adding fundamental new syntax, it removes a piece of C-legacy:<div class=""><br class=""></div><div class="">Basically,instead of</div><div class="">func f(args: Int…)</div><div class="">you would just declare</div><div class="">func f(args: @variadic [Int])</div><div class="">or even</div><div class="">func f(args: [Int])<br class=""><div class="">and interpret any argument that’s a comma-separated list as an array — or, and that’s imho another useful aspect, something else that can be expressed with an array literal</div><div class="">func f(args: Set<Int>)</div><div class=""><br class=""></div><div class="">So you would not only make the language surface smaller, but also add new abilities that basically come for free (they would still have to be implemented, though ;-)</div><div class=""><br class=""><blockquote type="cite" class=""><div class="">Am 30.11.2017 um 22:13 schrieb Cao, Jiannan via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>>:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html; charset=gb2312" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><pre style="white-space: pre-wrap; background-color: rgb(255, 255, 255);" class=""></pre>What happened with this proposal? This looks easy to implement.<div class=""><br class=""></div><div class=""><pre class="lang-swift prettyprint prettyprinted" style="margin-top: 0px; margin-bottom: 1em; padding: 5px; border: 0px; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-size: 13px; font-stretch: inherit; line-height: inherit; vertical-align: baseline; width: auto; max-height: 600px; overflow: auto; background-color: rgb(239, 240, 241); color: rgb(57, 51, 24); word-wrap: normal;"><code style="margin: 0px; padding: 0px; border: 0px; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; white-space: inherit;" class=""><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(16, 16, 148);"><pre class="lang-swift prettyprint prettyprinted" style="margin-top: 0px; margin-bottom: 0px; padding: 5px; border: 0px; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-stretch: inherit; line-height: inherit; vertical-align: baseline; width: auto; max-height: 600px; overflow: auto; color: rgb(57, 51, 24); word-wrap: normal;"><code style="margin: 0px; padding: 0px; border: 0px; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; white-space: inherit;" class=""><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(16, 16, 148);">func</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> sumOf</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">(</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">numbers</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">:</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(43, 145, 175);">Int</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">...)</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> </span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">-></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(43, 145, 175);">Int</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> </span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">{</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">
</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">...</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">
</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">}</span></code></pre></span></code></pre><pre class="lang-swift prettyprint prettyprinted" style="margin-top: 0px; margin-bottom: 1em; padding: 5px; border: 0px; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-size: 13px; font-stretch: inherit; line-height: inherit; vertical-align: baseline; width: auto; max-height: 600px; overflow: auto; background-color: rgb(239, 240, 241); color: rgb(57, 51, 24); word-wrap: normal;"><code style="margin: 0px; padding: 0px; border: 0px; font-family: Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; white-space: inherit;" class=""><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(16, 16, 148);">typealias</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(43, 145, 175);">Function</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> </span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">=</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> </span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">[</span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(43, 145, 175);">Int</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">]</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> </span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">-></span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(43, 145, 175);">Int</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">
</span><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(16, 16, 148);">let</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> sumOfArray </span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">=</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> unsafeBitCast</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">(</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">sumOf</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">,</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(43, 145, 175);">Function</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">.</span><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(16, 16, 148);">self</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">)</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">
sumOfArray</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">([</span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(125, 39, 39);">1</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">,</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(125, 39, 39);">2</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">,</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);"> </span><span class="lit" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(125, 39, 39);">3</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-size: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; color: rgb(48, 51, 54);">])</span></code></pre><div class=""><br class=""></div><blockquote type="cite" class=""><pre style="white-space: pre-wrap; background-color: rgb(255, 255, 255);" class="">Hello everyone.
I understand that topic has already been discussed in the past, but I failed to get any information on its current state of affairs.
I guess the subject of this mail is explicit, but to make sure I’m clear, here's a small snippet that illustrates the problem:
func f(args: Int…) {
// Some implementation ...
}
// Now it's impossible to call f without explicitly naming its parameters.
For many use-cases, this problem can be solved by overloading f so that it explicitly accepts an array.
func f(_ args: [Int]) {
// Some implementation ...
}
func f(_ args: Int…) {
f(args)
}
Some people also advocate (myself generally included) that one should prefer the signature explicitly marking args as an array, as the syntactic overhead of wrapping the arguments with “[]” when calling f is arguably bearable. However, in some other situations, this approach might not be applicable. For instance, one may simply not be able to modify the original function. Another use-case may be a function that should forward its own variadic parameters.
In a variety of other languages, there exists a way to do this. For instance, Python can “unpack” (or splat) a list into function arguments by prefixing it with *:
def f(*args):
# Some implementation …
f(*[1, 2, 3]) # == f(1, 2, 3)
I was wondering if such feature could be supported by Swift, and if not, why.
Syntactically, I like the use of “…”, which would mirror function signatures:
f(…[1, 2, 3]) // == f(1, 2, 3)
Thanks.
--
Dimitri Racordon</pre></blockquote><div class=""><br class=""></div></div></div>_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""></div></blockquote></div><br class=""></div></div></div></blockquote></div><br class=""></div></body></html>