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<h1 class='fqn'><span class='in-band'>Function <a href='index.html'>itertools</a>::<wbr><a class="fn" href=''>process_results</a></span><span class='out-of-band'><span id='render-detail'>
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[<span class='inner'>&#x2212;</span>]
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</span><a class='srclink' href='../src/itertools/process_results_impl.rs.html#71-81' title='goto source code'>[src]</a></span></h1>
<pre class='rust fn'>pub fn process_results&lt;I, F, T, E, R&gt;(iterable: I, processor: F) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;R, E&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;I: <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html" title="trait core::iter::traits::IntoIterator">IntoIterator</a>&lt;Item = <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;T, E&gt;&gt;,<br>&nbsp;&nbsp;&nbsp;&nbsp;F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>(<a class="struct" href="../itertools/structs/struct.ProcessResults.html" title="struct itertools::structs::ProcessResults">ProcessResults</a>&lt;I::<a class="type" href="https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html#associatedtype.IntoIter" title="type core::iter::traits::IntoIterator::IntoIter">IntoIter</a>, E&gt;) -&gt; R,&nbsp;</span></pre><div class='docblock'><p>“Lift” a function of the values of an iterator so that it can process
an iterator of <code>Result</code> values instead.</p>
<p><code>iterable</code> is an iterator or iterable with <code>Result&lt;T, E&gt;</code> elements, where
<code>T</code> is the value type and <code>E</code> the error type.</p>
<p><code>processor</code> is a closure that receives an adapted version of the iterable
as the only argument — the adapted iterator produces elements of type <code>T</code>,
as long as the original iterator produces <code>Ok</code> values.</p>
<p>If the original iterable produces an error at any point, the adapted
iterator ends and the <code>process_results</code> function will return the
error iself.</p>
<p>Otherwise, the return value from the closure is returned wrapped
inside <code>Ok</code>.</p>
<h1 id="example" class="section-header"><a href="#example">Example</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">itertools</span>::<span class="ident">process_results</span>;
<span class="kw">type</span> <span class="ident">R</span> <span class="op">=</span> <span class="prelude-ty">Result</span><span class="op">&lt;</span><span class="ident">i32</span>, <span class="kw-2">&amp;</span><span class="lifetime">&#39;static</span> <span class="ident">str</span><span class="op">&gt;</span>;
<span class="kw">let</span> <span class="ident">first_values</span>: <span class="ident">Vec</span><span class="op">&lt;</span><span class="ident">R</span><span class="op">&gt;</span> <span class="op">=</span> <span class="macro">vec</span><span class="macro">!</span>[<span class="prelude-val">Ok</span>(<span class="number">1</span>), <span class="prelude-val">Ok</span>(<span class="number">0</span>), <span class="prelude-val">Ok</span>(<span class="number">3</span>)];
<span class="kw">let</span> <span class="ident">second_values</span>: <span class="ident">Vec</span><span class="op">&lt;</span><span class="ident">R</span><span class="op">&gt;</span> <span class="op">=</span> <span class="macro">vec</span><span class="macro">!</span>[<span class="prelude-val">Ok</span>(<span class="number">2</span>), <span class="prelude-val">Ok</span>(<span class="number">1</span>), <span class="prelude-val">Err</span>(<span class="string">&quot;overflow&quot;</span>)];
<span class="comment">// “Lift” the iterator .max() method to work on the values in Results using process_results</span>
<span class="kw">let</span> <span class="ident">first_max</span> <span class="op">=</span> <span class="ident">process_results</span>(<span class="ident">first_values</span>, <span class="op">|</span><span class="ident">iter</span><span class="op">|</span> <span class="ident">iter</span>.<span class="ident">max</span>().<span class="ident">unwrap_or</span>(<span class="number">0</span>));
<span class="kw">let</span> <span class="ident">second_max</span> <span class="op">=</span> <span class="ident">process_results</span>(<span class="ident">second_values</span>, <span class="op">|</span><span class="ident">iter</span><span class="op">|</span> <span class="ident">iter</span>.<span class="ident">max</span>().<span class="ident">unwrap_or</span>(<span class="number">0</span>));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">first_max</span>, <span class="prelude-val">Ok</span>(<span class="number">3</span>));
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">second_max</span>.<span class="ident">is_err</span>());</pre>
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