s="ident">read</span>(<span class="ident">serial</span>).<span class="ident">and_then</span>(<span class="op">|</span>(<span class="ident">serial</span>, <span class="ident">byte</span>)<span class="op">|</span> {
            <span class="ident">write</span>(<span class="ident">serial</span>, <span class="ident">byte</span>)
        }).<span class="ident">map</span>(<span class="op">|</span><span class="ident">serial</span><span class="op">|</span> {
            <span class="ident">Loop</span>::<span class=