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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>Dear Swift community,</p>
<p>while building a framework for BSON I had the following idea.</p>
<p>Here is a snippet of some code I do have in my module:</p>
<pre><code class="swift">extension Array where Element == Document.Value {
public func double(at index: Int) -> Double? {
guard self.startIndex <= index && index < self.endIndex else { return nil }
if case .double(let double) = self[index] {
return double
}
return nil
}
…
}
</code></pre>
<p>This function is used to query the array and check if the element at the given index is of a specific type. Now I would like also to implement a semi-schema setter.</p>
<p>The problem that I see, is the ugliness of the <code>subscript</code> I’d create.</p>
<p>Currently the code would read nicely <code>let d = array.double(at: 42)</code>, but after change to a <code>subscript</code> the API would look odd <code>array[doubleAt: 42] = 5.0</code>.</p>
<p>Don’t get me wrong here, I also have methods with larger names like <code>public func scopedJavaScript(at index: Int) -> …</code>. You can easily imagine that such subscripts would look ugly <code>array[scopedJavaScriptAt: 123] = …</code>.</p>
<p>I propose to align the design of subscript with functions where one could optionally give subscript a name.</p>
<pre><code class="swift">func name(label parameter: Type) -> ReturnType
subscript optionalName(label parameter: Type) -> ReturnType
</code></pre>
<p>This change would make my API nice and clean. <code>array.scopedJavaScript[at: 213] = …</code></p>
<p>This also might be the opportunity to rethink the labeling rule on subscripts, but this shall not be the main focus of this pitch.</p>
<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_1479412498260118016" class="bloop_sign"><div style="font-family:helvetica,arial;font-size:13px">-- <br>Adrian Zubarev<br>Sent with Airmail</div></div></div><div class="bloop_markdown"><p></p></div></body></html>