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.send { color:#77bb77; }
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.error { color:#AA0000; }</style></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div class="bloop_markdown"><p>Hi Dave,</p>
<p>Thank you for your answer. I have to admit this is a ‘workaround’ but it will make everything even worse.</p>
<p>From:</p>
<pre><code class="swift">public func scopedJavaScript(at index: Int) -> (javaScript: String, scope: Document)?
</code></pre>
<p>To:</p>
<pre><code class="swift">public subscript(at index: Int) -> (javaScript: String, scope: Document)?
public var scopedJavaScript: Array {
get { return self }
set { /* implementation artifact */ }
}
</code></pre>
<p>Now I could write code like <code>array.scopedJavaScript.scopedJavaScript.scopedJavaScript</code> and so one, which makes no sense any more.</p>
<p>Where we could simply allow:</p>
<pre><code class="swift">public subscript scopedJavaScript(at index: Int) -> (javaScript: String, scope: Document)?
</code></pre>
<p>This would ensure that the user can only write something like:</p>
<pre><code class="swift">array.scopedJavaScript[at: 42] // get the value
array.scopedJavaScript[at: 42] = (…, …) // set the value
</code></pre>
<ul>
<li>Is there anything that speaks against optionally named subscripts?</li>
<li>Technical reasons?</li>
<li>Swiftiness?</li>
</ul>
<p></p></div><div class="bloop_original_html"><style>body{font-family:Helvetica,Arial;font-size:13px}</style><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div> <br> <div id="bloop_sign_1479455258346931968" class="bloop_sign"><div style="font-family:helvetica,arial;font-size:13px">-- <br>Adrian Zubarev<br>Sent with Airmail</div></div> <br><p class="airmail_on">Am 17. November 2016 um 23:33:44, Dave Abrahams via swift-evolution (<a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a>) schrieb:</p> <blockquote type="cite" class="clean_bq"><span><div><div></div><div><br>on Thu Nov 17 2016, Adrian Zubarev <swift-evolution@swift.org> wrote:<br><br>> Dear Swift community,<br>><br>> while building a framework for BSON I had the following idea.<br>><br>> Here is a snippet of some code I do have in my module:<br>><br>> extension Array where Element == Document.Value {<br>><br>> public func double(at index: Int) -> Double? {<br>><br>> guard self.startIndex <= index && index < self.endIndex else { return nil }<br>><br>> if case .double(let double) = self[index] {<br>><br>> return double<br>> }<br>> return nil<br>> }<br>><br>> …<br>> }<br>> This function is used to query the array and check if the element at the given index is of a<br>> specific type. Now I would like also to implement a semi-schema setter.<br>><br>> The problem that I see, is the ugliness of the subscript I’d create.<br>><br>> Currently the code would read nicely let d = array.double(at: 42), but after change to a subscript<br>> the API would look odd array[doubleAt: 42] = 5.0.<br>><br>> Don’t get me wrong here, I also have methods with larger names like public func scopedJavaScript(at<br>> index: Int) -> …. You can easily imagine that such subscripts would look ugly<br>> array[scopedJavaScriptAt: 123] = ….<br>><br>> I propose to align the design of subscript with functions where one could optionally give subscript<br>> a name.<br>><br>> func name(label parameter: Type) -> ReturnType<br>><br>> subscript optionalName(label parameter: Type) -> ReturnType<br>> This change would make my API nice and<br>> clean. array.scopedJavaScript[at: 213] = …<br><br>You do that by giving your Array a scopedJavaScript property, and<br>making that indexable.<br><br>-- <br>-Dave<br><br>_______________________________________________<br>swift-evolution mailing list<br>swift-evolution@swift.org<br>https://lists.swift.org/mailman/listinfo/swift-evolution<br></div></div></span></blockquote></div><div class="bloop_markdown"><p></p></div></body></html>