<html><head><style>
body {
font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
padding:1em;
margin:auto;
background:#fefefe;
}
h1, h2, h3, h4, h5, h6 {
font-weight: bold;
}
h1 {
color: #000000;
font-size: 28pt;
}
h2 {
border-bottom: 1px solid #CCCCCC;
color: #000000;
font-size: 24px;
}
h3 {
font-size: 18px;
}
h4 {
font-size: 16px;
}
h5 {
font-size: 14px;
}
h6 {
color: #777777;
background-color: inherit;
font-size: 14px;
}
hr {
height: 0.2em;
border: 0;
color: #CCCCCC;
background-color: #CCCCCC;
display: inherit;
}
p, blockquote, ul, ol, dl, li, table, pre {
margin: 15px 0;
}
a, a:visited {
color: #4183C4;
background-color: inherit;
text-decoration: none;
}
#message {
border-radius: 6px;
border: 1px solid #ccc;
display:block;
width:100%;
height:60px;
margin:6px 0px;
}
button, #ws {
font-size: 12 pt;
padding: 4px 6px;
border-radius: 5px;
border: 1px solid #bbb;
background-color: #eee;
}
code, pre, #ws, #message {
font-family: Monaco;
font-size: 10pt;
border-radius: 3px;
background-color: #F8F8F8;
color: inherit;
}
code {
border: 1px solid #EAEAEA;
margin: 0 2px;
padding: 0 5px;
}
pre {
border: 1px solid #CCCCCC;
overflow: auto;
padding: 4px 8px;
}
pre > code {
border: 0;
margin: 0;
padding: 0;
}
#ws { background-color: #f8f8f8; }
.bloop_markdown table {
border-collapse: collapse;
font-family: Helvetica, arial, freesans, clean, sans-serif;
color: rgb(51, 51, 51);
font-size: 15px; line-height: 25px;
padding: 0; }
.bloop_markdown table tr {
border-top: 1px solid #cccccc;
background-color: white;
margin: 0;
padding: 0; }
.bloop_markdown table tr:nth-child(2n) {
background-color: #f8f8f8; }
.bloop_markdown table tr th {
font-weight: bold;
border: 1px solid #cccccc;
margin: 0;
padding: 6px 13px; }
.bloop_markdown table tr td {
border: 1px solid #cccccc;
margin: 0;
padding: 6px 13px; }
.bloop_markdown table tr th :first-child, table tr td :first-child {
margin-top: 0; }
.bloop_markdown table tr th :last-child, table tr td :last-child {
margin-bottom: 0; }
.bloop_markdown blockquote{
border-left: 4px solid #dddddd;
padding: 0 15px;
color: #777777; }
blockquote > :first-child {
margin-top: 0; }
blockquote > :last-child {
margin-bottom: 0; }
code, pre, #ws, #message {
word-break: normal;
word-wrap: normal;
}
hr {
display: inherit;
}
.bloop_markdown :first-child {
-webkit-margin-before: 0;
}
code, pre, #ws, #message {
font-family: Menlo, Consolas, Liberation Mono, Courier, monospace;
}
.send { color:#77bb77; }
.server { color:#7799bb; }
.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>There is one thing that I want to point out with pitched syntactic sugar. <code>GenericMyProtocolName<U></code> will also let you reuse <code>T</code> within a generic type, where currently we cannot nest protocols into types. Even if we could, it’s not clear if nested declarations like <code>protocol MyTProtocolName : MyProtocolName where U == T</code> would be possible, so that <code>T</code> from the outer generic type is accessible. </p>
<p>Autogenerating the only possible generic protocols from protocols with associated types as a syntactic sugar to reduce spawning of types like <code>IntFoo</code> (as previously showed) seems reasonable to me. It does not break the current protocol system, but solves the first generic protocol feature from the generics manifesto.</p>
<p>There are still a few more questioned to answer:</p>
<ul>
<li>How dow we want the generated parameter list to look like?</li>
<li>Can we drop <code>Generic</code> prefix without collisions?</li>
<li>Does this syntactic sugar improves the stdlib or affect ABI?</li>
</ul>
<p>There are probably some more questions I cannot foresee by myself. Feel free to jump in the discussion. ;)</p>
<p>PS: Yes this syntactic sugar does create an alternative way of creating ‘kinda’ the same protocol twice, but it reuses the pattern more naturally.</p>
<pre><code class="swift">protocol Foo { associatetype Inner : SomeOtherProtocol }
// Assuming String and Int conforms to SomeOtherProtocol
protocol StringFoo : Foo where Inner == String {}
protocol IntFoo : Foo where Inner == Int {}
// VS.
// autogenerated
procotol GenericFoo<Inner : SomeOtherProtocol> : Foo { … }
// usage
GenericFoo<String>
GenericFoo<Int>
// or
typealias StringFoo = GenericFoo<String>
typealias IntFoo = GenericFoo<Int>
</code></pre>
<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_1480780772434896896" 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 3. Dezember 2016 um 16:43:43, Daniel Leping (<a href="mailto:daniel@crossroadlabs.xyz">daniel@crossroadlabs.xyz</a>) schrieb:</p> <blockquote type="cite" class="clean_bq"><span><div><div></div><div>
<title></title>
<div style="white-space:pre-wrap">In general I'm very positive with
the idea of generic protocols. This discussion is more about
syntactic sugar, though I really like where it goes.<br>
<br>
Off topic:<br>
IMO, we should revisit approaches others already use for conflicts
resolution. I personally tend to get something similar to Scala
traits. Should fit POT smoothly and naturally.</div>
<br>
<div class="gmail_quote">
<div dir="ltr">On Sat, 3 Dec 2016 at 16:30 Adrian Zubarev
<<a href="mailto:adrian.zubarev@devandartist.com">adrian.zubarev@devandartist.com</a>>
wrote:<br></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" class="gmail_msg">
<div class="m_6921161786416199282bloop_markdown gmail_msg">
<p class="gmail_msg">If I’m not mistaken here, <code class="gmail_msg">extension Foo where T == Int</code> will have an error
of redeclaration <code class="gmail_msg">foo</code> anyways.</p>
<p class="gmail_msg"></p>
</div>
<div class="m_6921161786416199282bloop_original_html gmail_msg">
</div>
</div>
<div style="word-wrap:break-word" class="gmail_msg">
<div class="m_6921161786416199282bloop_original_html gmail_msg">
<div id="m_6921161786416199282bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px;color:rgba(0,0,0,1.0);margin:0px;line-height:auto" class="gmail_msg"><br class="gmail_msg"></div>
<div id="m_6921161786416199282bloop_sign_1480775153794472960" class="m_6921161786416199282bloop_sign gmail_msg">
<div style="font-family:helvetica,arial;font-size:13px" class="gmail_msg">-- <br class="gmail_msg">
Adrian Zubarev<br class="gmail_msg">
Sent with Airmail</div>
</div>
<br class="gmail_msg"></div>
</div>
<div style="word-wrap:break-word" class="gmail_msg">
<div class="m_6921161786416199282bloop_original_html gmail_msg">
<p class="m_6921161786416199282airmail_on gmail_msg">Am 3. Dezember
2016 um 15:22:56, Adrian Zubarev (<a href="mailto:adrian.zubarev@devandartist.com" class="gmail_msg" target="_blank">adrian.zubarev@devandartist.com</a>) schrieb:</p>
<blockquote type="cite" class="m_6921161786416199282clean_bq gmail_msg">
<div class="gmail_msg">
<pre style="margin:15px 0px;font-family:Menlo,Consolas,'Liberation Mono',Courier,monospace;font-size:10pt;border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;background-color:rgb(248,248,248);color:rgb(0,0,0);border:1px solid rgb(204,204,204);overflow:auto;padding:4px 8px;word-break:normal;word-wrap:normal;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px" class="gmail_msg"><span class="gmail_msg"><code class="m_6921161786416199282swift gmail_msg" style="font-family:Menlo,Consolas,'Liberation Mono',Courier,monospace;font-size:10pt;border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;background-color:rgb(248,248,248);color:inherit;border:0px;margin:0px;padding:0px;word-break:normal;word-wrap:normal">extension Foo where T == Int {
func foo() {
self.bar(o: 42) // calls a function that accepts an Int
}
}</code></span></pre></div>
</blockquote>
</div>
</div>
</blockquote>
</div>
</div></div></span></blockquote></div><div class="bloop_markdown"><p></p></div></body></html>