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</pre><pre class="rust ">
<span class="kw">use</span> <span class="ident">core</span>::<span class="ident">mem</span>;
<span class="kw">use</span> <span class="ident">core</span>::<span class="ident">marker</span>::<span class="ident">PhantomData</span>;
<span class="kw">use</span> {<span class="ident">IntoFuture</span>, <span class="ident">Future</span>, <span class="ident">Poll</span>, <span class="ident">Async</span>, <span class="ident">StartSend</span>, <span class="ident">AsyncSink</span>};
<span class="kw">use</span> <span class="ident">sink</span>::<span class="ident">Sink</span>;
<span class="kw">use</span> <span class="ident">stream</span>::<span class="ident">Stream</span>;
<span class="doccomment">/// Sink for the `Sink::with` combinator, chaining a computation to run *prior*</span>
<span class="doccomment">/// to pushing a value into the underlying sink.</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>)]</span>
<span class="attribute">#[<span class="ident">must_use</span> <span class="op">=</span> <span class="string">"sinks do nothing unless polled"</span>]</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">With</span><span class="op"><</span><span class="ident">S</span>, <span class="ident">U</span>, <span class="ident">F</span>, <span class="ident">Fut</span><span class="op">></span>
<span class="kw">where</span> <span class="ident">S</span>: <span class="ident">Sink</span>,
<span class="ident">F</span>: <span class="ident">FnMut</span>(<span class="ident">U</span>) <span class="op">-></span> <span class="ident">Fut</span>,
<span class="ident">Fut</span>: <span class="ident">IntoFuture</span>,
{
<span class="ident">sink</span>: <span class="ident">S</span>,
<span class="ident">f</span>: <span class="ident">F</span>,
<span class="ident">state</span>: <span class="ident">State</span><span class="op"><</span><span class="ident">Fut</span>::<span class="ident">Future</span>, <span class="ident">S</span>::<span class="ident">SinkItem</span><span class="op">></span>,
<span class="ident">_phantom</span>: <span class="ident">PhantomData</span><span class="op"><</span><span class="kw">fn</span>(<span class="ident">U</span>)<span class="op">></span>,
}
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>)]</span>
<span class="kw">enum</span> <span class="ident">State</span><span class="op"><</span><span class="ident">Fut</span>, <span class="ident">T</span><span class="op">></span> {
<span class="ident">Empty</span>,
<span class="ident">Process</span>(<span class="ident">Fut</span>),
<span class="ident">Buffered</span>(<span class="ident">T</span>),
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">Fut</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">State</span><span class="op"><</span><span class="ident">Fut</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">is_empty</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">bool</span> {
<span class="kw">if</span> <span class="kw">let</span> <span class="ident">State</span>::<span class="ident">Empty</span> <span class="op">=</span> <span class="kw-2">*</span><span class="self">self</span> {
<span class="bool-val">true</span>
} <span class="kw">else</span> {
<span class="bool-val">false</span>
}
}
}
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span><span class="op"><</span><span class="ident">S</span>, <span class="ident">U</span>, <span class="ident">F</span>, <span class="ident">Fut</span><span class="op">></span>(<span class="ident">sink</span>: <span class="ident">S</span>, <span class="ident">f</span>: <span class="ident">F</span>) <span class="op">-></span> <span class="ident">With</span><span class="op"><</span><span class="ident">S</span>, <span class="ident">U</span>, <span class="ident">F</span>, <span class="ident">Fut</span><span class="op">></span>
<span class="kw">where</span> <span class="ident">S</span>: <span class="ident">Sink</span>,
<span class="ident">F</span>: <span class="ident">FnMut</span>(<span class="ident">U</span>) <span class="op">-></span> <span class="ident">Fut</span>,
<span class="ident">Fut</span>: <span class="ident">IntoFuture</span><span class="op"><</span><span class="ident">Item</span> <span class="op">=</span> <span class="ident">S</span>::<span class="ident">SinkItem</span><span class="op">></span>,
<span class="ident">Fut</span>::<span class="ident">Error</span>: <span class="ident">From</span><span class="op"><</span><span class="ident">S</span>::<span class="ident">SinkError</span><span class="op">></span>,
{
<span class="ident">With</span> {
<span class="ident">state</span>: <span class="ident">State</span>::<span class="ident">Empty</span>,
<span class="ident">sink</span>: <span class="ident">sink</span>,
<span class="ident">f</span>: <span class="ident">f</span>,
<span class="ident">_phantom</span>: <span class="ident">PhantomData</span>,
}
}
<span class="comment">// Forwarding impl of Stream from the underlying sink</span>
<span class="kw">impl</span><span class="op"><</span><span class="ident">S</span>, <span class="ident">U</span>, <span class="ident">F</span>, <span class="ident">Fut</span><span class="op">></span> <span class="ident">Stream</span> <span class="kw">for</span> <span class="ident">With</span><span class="op"><</span><span class="ident">S</span>, <span class="ident">U</span>, <span class="ident">F</span>, <span class="ident">Fut</span><span class="op">></span>
<span class="kw">where</span> <span class="ident">S</span>: <span class="ident">Stream</span> <span class="op">+</span> <span class="ident">Sink</span>,
<span class="ident">F</span>: <span class="ident">FnMut</span>(<span class="ident">U</span>) <span class="op">-></span> <span class="ident">Fut</span>,
<span class="ident">Fut</span>: <span class="ident">IntoFuture</span>
{
<span class="kw">type</span> <span class="ident">Item</span> <span class="op">=</span> <span class="ident">S</span>::<span class="ident">Item</span>;
<span class="kw">type</span> <span class="ident">Error</span> <span class="op">=</span> <span class="ident">S</span>::<span class="ident">Error</span>;
<span class="kw">fn</span> <span class="ident">poll</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="ident">Poll</span><span class="op"><</span><span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">S</span>::<span class="ident">Item</span><span class="op">></span>, <span class="ident">S</span>::<span class="ident">Error</span><span class="op">></span> {
<span class="self">self</span>.<span class="ident">sink</span>.<span class="ident">poll</span>()
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">S</span>, <span class="ident">U</span>, <span class="ident">F</span>, <span class="ident">Fut</span><span class="op">></span> <span class="ident">With</span><span class="op"><</span><span class="ident">S</span>, <span class="ident">U</span>, <span class="ident">F</span>, <span class="ident">Fut</span><span class="op">></span>
<span class="kw">where</span> <span class="ident">S</span>: <span class="ident">Sink</span>,
<span class="ident">F</span>: <span class="ident">FnMut</span>(<span class="ident">U</span>) <span class="op">-></span> <span class="ident">Fut</span>,
<span class="ident">Fut</span>: <span class="ident">IntoFuture</span><span class="op"><</span><span class="ident">Item</span> <span class="op">=</span> <span class="ident">S</span>::<span class="ident">SinkItem</span><span class="op">></span>,
<span class="ident">Fut</span>::<span class="ident">Error</span>: <span class="ident">From</span><span class="op"><</span><span class="ident">S</span>::<span class="ident">SinkError</span><span class="op">></span>,
{
<span class="doccomment">/// Get a shared reference to the inner sink.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">get_ref</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="kw-2">&</span><span class="ident">S</span> {
<span class="kw-2">&</span><span class="self">self</span>.<span class="ident">sink</span>
}
<span class="doccomment">/// Get a mutable reference to the inner sink.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">get_mut</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">S</span> {
<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>.<span class="ident">sink</span>
}
<span class="doccomment">/// Consumes this combinator, returning the underlying sink.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Note that this may discard intermediate state of this combinator, so</span>
<span class="doccomment">/// care should be taken to avoid losing resources when this is called.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">into_inner</span>(<span class="self">self</span>) <span class="op">-></span> <span class="ident">S</span> {
<span class="self">self</span>.<span class="ident">sink</span>
}
<span class="kw">fn</span> <span class="ident">poll</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="ident">Poll</span><span class="op"><</span>(), <span class="ident">Fut</span>::<span class="ident">Error</span><span class="op">></span> {
<span class="kw">loop</span> {
<span class="kw">match</span> <span class="ident">mem</span>::<span class="ident">replace</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>.<span class="ident">state</span>, <span class="ident">State</span>::<span class="ident">Empty</span>) {
<span class="ident">State</span>::<span class="ident">Empty</span> <span class="op">=></span> <span class="kw">break</span>,
<span class="ident">State</span>::<span class="ident">Process</span>(<span class="kw-2">mut</span> <span class="ident">fut</span>) <span class="op">=></span> {
<span class="kw">match</span> <span class="ident">fut</span>.<span class="ident">poll</span>()<span class="question-mark">?</span> {
<span class="ident">Async</span>::<span class="ident">Ready</span>(<span class="ident">item</span>) <span class="op">=></span> {
<span class="self">self</span>.<span class="ident">state</span> <span class="op">=</span> <span class="ident">State</span>::<span class="ident">Buffered</span>(<span class="ident">item</span>);
}
<span class="ident">Async</span>::<span class="ident">NotReady</span> <span class="op">=></span> {
<span class="self">self</span>.<span class="ident">state</span> <span class="op">=</span> <span class="ident">State</span>::<span class="ident">Process</span>(<span class="ident">fut</span>);
<span class="kw">break</span>
}
}
}
<span class="ident">State</span>::<span class="ident">Buffered</span>(<span class="ident">item</span>) <span class="op">=></span> {
<span class="kw">if</span> <span class="kw">let</span> <span class="ident">AsyncSink</span>::<span class="ident">NotReady</span>(<span class="ident">item</span>) <span class="op">=</span> <span class="self">self</span>.<span class="ident">sink</span>.<span class="ident">start_send</span>(<span class="ident">item</span>)<span class="question-mark">?</span> {
<span class="self">self</span>.<span class="ident">state</span> <span class="op">=</span> <span class="ident">State</span>::<span class="ident">Buffered</span>(<span class="ident">item</span>);
<span class="kw">break</span>
}
}
}
}
<span class="kw">if</span> <span class="self">self</span>.<span class="ident">state</span>.<span class="ident">is_empty</span>() {
<span class="prelude-val">Ok</span>(<span class="ident">Async</span>::<span class="ident">Ready</span>(()))
} <span class="kw">else</span> {
<span class="prelude-val">Ok</span>(<span class="ident">Async</span>::<span class="ident">NotReady</span>)
}
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">S</span>, <span class="ident">U</span>, <span class="ident">F</span>, <span class="ident">Fut</span><span class="op">></span> <span class="ident">Sink</span> <span class="kw">for</span> <span class="ident">With</span><span class="op"><</span><span class="ident">S</span>, <span class="ident">U</span>, <span class="ident">F</span>, <span class="ident">Fut</span><span class="op">></span>
<span class="kw">where</span> <span class="ident">S</span>: <span class="ident">Sink</span>,
<span class="ident">F</span>: <span class="ident">FnMut</span>(<span class="ident">U</span>) <span class="op">-></span> <span class="ident">Fut</span>,
<span class="ident">Fut</span>: <span class="ident">IntoFuture</span><span class="op"><</span><span class="ident">Item</span> <span class="op">=</span> <span class="ident">S</span>::<span class="ident">SinkItem</span><span class="op">></span>,
<span class="ident">Fut</span>::<span class="ident">Error</span>: <span class="ident">From</span><span class="op"><</span><span class="ident">S</span>::<span class="ident">SinkError</span><span class="op">></span>,
{
<span class="kw">type</span> <span class="ident">SinkItem</span> <span class="op">=</span> <span class="ident">U</span>;
<span class="kw">type</span> <span class="ident">SinkError</span> <span class="op">=</span> <span class="ident">Fut</span>::<span class="ident">Error</span>;
<span class="kw">fn</span> <span class="ident">start_send</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">item</span>: <span class="self">Self</span>::<span class="ident">SinkItem</span>) <span class="op">-></span> <span class="ident">StartSend</span><span class="op"><</span><span class="self">Self</span>::<span class="ident">SinkItem</span>, <span class="ident">Fut</span>::<span class="ident">Error</span><span class="op">></span> {
<span class="kw">if</span> <span class="self">self</span>.<span class="ident">poll</span>()<span class="question-mark">?</span>.<span class="ident">is_not_ready</span>() {
<span class="kw">return</span> <span class="prelude-val">Ok</span>(<span class="ident">AsyncSink</span>::<span class="ident">NotReady</span>(<span class="ident">item</span>))
}
<span class="self">self</span>.<span class="ident">state</span> <span class="op">=</span> <span class="ident">State</span>::<span class="ident">Process</span>((<span class="self">self</span>.<span class="ident">f</span>)(<span class="ident">item</span>).<span class="ident">into_future</span>());
<span class="prelude-val">Ok</span>(<span class="ident">AsyncSink</span>::<span class="ident">Ready</span>)
}
<span class="kw">fn</span> <span class="ident">poll_complete</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="ident">Poll</span><span class="op"><</span>(), <span class="ident">Fut</span>::<span class="ident">Error</span><span class="op">></span> {
<span class="comment">// poll ourselves first, to push data downward</span>
<span class="kw">let</span> <span class="ident">me_ready</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">poll</span>()<span class="question-mark">?</span>;
<span class="comment">// always propagate `poll_complete` downward to attempt to make progress</span>
<span class="macro">try_ready</span><span class="macro">!</span>(<span class="self">self</span>.<span class="ident">sink</span>.<span class="ident">poll_complete</span>());
<span class="prelude-val">Ok</span>(<span class="ident">me_ready</span>)
}
<span class="kw">fn</span> <span class="ident">close</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="ident">Poll</span><span class="op"><</span>(), <span class="ident">Fut</span>::<span class="ident">Error</span><span class="op">></span> {
<span class="macro">try_ready</span><span class="macro">!</span>(<span class="self">self</span>.<span class="ident">poll</span>());
<span class="prelude-val">Ok</span>(<span class="self">self</span>.<span class="ident">sink</span>.<span class="ident">close</span>()<span class="question-mark">?</span>)
}
}
</pre>
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<dl>
<dt><kbd>?</kbd></dt>
<dd>Show this help dialog</dd>
<dt><kbd>S</kbd></dt>
<dd>Focus the search field</dd>
<dt><kbd>↑</kbd></dt>
<dd>Move up in search results</dd>
<dt><kbd>↓</kbd></dt>
<dd>Move down in search results</dd>
<dt><kbd>↹</kbd></dt>
<dd>Switch tab</dd>
<dt><kbd>⏎</kbd></dt>
<dd>Go to active search result</dd>
<dt><kbd>+</kbd></dt>
<dd>Expand all sections</dd>
<dt><kbd>-</kbd></dt>
<dd>Collapse all sections</dd>
</dl>
</div>
<div class="infos">
<h2>Search Tricks</h2>
<p>
Prefix searches with a type followed by a colon (e.g.
<code>fn:</code>) to restrict the search to a given type.
</p>
<p>
Accepted types are: <code>fn</code>, <code>mod</code>,
<code>struct</code>, <code>enum</code>,
<code>trait</code>, <code>type</code>, <code>macro</code>,
and <code>const</code>.
</p>
<p>
Search functions by type signature (e.g.
<code>vec -> usize</code> or <code>* -> vec</code>)
</p>
</div>
</div>
</aside>
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