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<h1 class='fqn'><span class='in-band'><a href='index.html'>nom</a>::<wbr><a class='macro' href=''>is_a!</a></span><span class='out-of-band'><span id='render-detail'>
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</span><a id='src-7395' class='srclink' href='../src/nom/macros.rs.html#771-801' title='goto source code'>[src]</a></span></h1>
<pre class='rust macro'>
<span class='macro'>macro_rules</span><span class='macro'>!</span> <span class='ident'>is_a</span>(
(<span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>input</span>:<span class='ident'>expr</span>, <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>arr</span>:<span class='ident'>expr</span>) <span class='op'>=></span> (
{
<span class='attribute'>#[<span class='ident'>inline</span>(<span class='ident'>always</span>)]</span>
<span class='kw'>fn</span> <span class='ident'>as_bytes</span><span class='op'><</span><span class='ident'>T</span>: <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>crate</span>::<span class='ident'>util</span>::<span class='ident'>AsBytes</span><span class='op'>></span>(<span class='ident'>b</span>: <span class='kw-2'>&</span><span class='ident'>T</span>) <span class='op'>-></span> <span class='kw-2'>&</span>[<span class='ident'>u8</span>] {
<span class='ident'>b</span>.<span class='ident'>as_bytes</span>()
}
<span class='kw'>let</span> <span class='ident'>expected</span> <span class='op'>=</span> <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>arr</span>;
<span class='kw'>let</span> <span class='ident'>bytes</span> <span class='op'>=</span> <span class='ident'>as_bytes</span>(<span class='kw-2'>&</span><span class='ident'>expected</span>);
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>index</span> <span class='op'>=</span> <span class='number'>0</span>;
<span class='kw'>for</span> <span class='ident'>idx</span> <span class='kw'>in</span> <span class='number'>0</span>..<span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>input</span>.<span class='ident'>len</span>() {
<span class='ident'>index</span> <span class='op'>=</span> <span class='ident'>idx</span>;
<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>cont</span> <span class='op'>=</span> <span class='boolval'>false</span>;
<span class='kw'>for</span> <span class='kw-2'>&</span><span class='ident'>i</span> <span class='kw'>in</span> <span class='ident'>bytes</span>.<span class='ident'>iter</span>() {
<span class='kw'>if</span> <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>input</span>[<span class='ident'>idx</span>] <span class='op'>==</span> <span class='ident'>i</span> {
<span class='ident'>cont</span> <span class='op'>=</span> <span class='boolval'>true</span>;
<span class='kw'>break</span>;
}
}
<span class='kw'>if</span> <span class='op'>!</span><span class='ident'>cont</span> { <span class='kw'>break</span>; }
}
<span class='kw'>if</span> <span class='ident'>index</span> <span class='op'>==</span> <span class='number'>0</span> {
<span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>crate</span>::<span class='ident'>IResult</span>::<span class='ident'>Error</span>(<span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>crate</span>::<span class='prelude-val'>Err</span>::<span class='ident'>Position</span>(<span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>crate</span>::<span class='ident'>ErrorCode</span>::<span class='ident'>IsA</span> <span class='kw'>as</span> <span class='ident'>u32</span>,<span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>input</span>))
} <span class='kw'>else</span> {
<span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>crate</span>::<span class='ident'>IResult</span>::<span class='ident'>Done</span>(<span class='kw-2'>&</span><span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>input</span>[<span class='ident'>index</span>..], <span class='kw-2'>&</span><span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>input</span>[<span class='number'>0</span>..<span class='ident'>index</span>])
}
}
);
);
</pre>
<div class='docblock'><p>returns the longest list of bytes that appear in the provided array</p>
<pre class='rust rust-example-rendered'>
<span class='macro'>named</span><span class='macro'>!</span>(<span class='ident'>abcd</span>, <span class='macro'>is_a</span><span class='macro'>!</span>( <span class='string'>"abcd"</span> ));
<span class='kw'>let</span> <span class='ident'>r1</span> <span class='op'>=</span> <span class='ident'>abcd</span>(<span class='kw-2'>&</span><span class='string'>b"aaaaefgh"</span>[..]);
<span class='macro'>assert_eq</span><span class='macro'>!</span>(<span class='ident'>r1</span>, <span class='ident'>Done</span>(<span class='kw-2'>&</span><span class='string'>b"efgh"</span>[..], <span class='kw-2'>&</span><span class='string'>b"aaaa"</span>[..]));
<span class='kw'>let</span> <span class='ident'>r2</span> <span class='op'>=</span> <span class='ident'>abcd</span>(<span class='kw-2'>&</span><span class='string'>b"dcbaefgh"</span>[..]);
<span class='macro'>assert_eq</span><span class='macro'>!</span>(<span class='ident'>r2</span>, <span class='ident'>Done</span>(<span class='kw-2'>&</span><span class='string'>b"efgh"</span>[..], <span class='kw-2'>&</span><span class='string'>b"dcba"</span>[..]));
</pre>
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