class Nil | Raku Documentation

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href="/RakuDocumentation.epub" download>RakuDocumentation.epub</a> is a work in progress e-book. It targets the <a href="https://www.w3.org/publishing/epub3/">EPUB v3 specification</a>. It needs testing on a variety of ereaders (some of which may still implicitly expect compliance with EPUB v2). The CSS definitely needs enhancing (especially for code snippets). 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It may also be used as a cheaper and less explosive alternative to a <a href="/type/Failure"><code>Failure</code></a>. (In fact, class <a href="/type/Failure"><code>Failure</code></a> is derived from <code>Nil</code>, so smartmatching <code>Nil</code> will also match <a href="/type/Failure"><code>Failure</code></a>.)</p><p>The class <code>Nil</code> is the same exact thing as its only possible value, <code>Nil</code>.</p> <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-ROUTINE">say</span> <span class="highlite-TYPE">Nil</span> <span class="highlite-OPERATOR">===</span> <span class="highlite-TYPE">Nil</span>.<span class="highlite-ROUTINE">new</span>; <span class="highlite-COMMENT"># OUTPUT: «True␤»</span></pre> </div> </div> <p>Along with <a href="/type/Failure"><code>Failure</code></a>, <code>Nil</code> and its subclasses may always be returned from a routine even when the routine specifies a particular return type. It may also be returned regardless of the definedness of the return type, however, <code>Nil</code> is considered undefined for all other purposes.</p> <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">sub</span> a( <span class="highlite-KEYWORD">--></span> Int:D ) { <span class="highlite-KEYWORD">return</span> <span class="highlite-TYPE">Nil</span> } a().<span class="highlite-ROUTINE">say</span>; <span class="highlite-COMMENT"># OUTPUT: «Nil␤»</span></pre> </div> </div> <p><code>Nil</code> is what is returned from empty routines or closure, or routines that use a bare <code>return</code> statement.</p> <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">sub</span> a { }; a().<span class="highlite-ROUTINE">say</span>; <span class="highlite-COMMENT"># OUTPUT: «Nil␤» </span><span class="highlite-KEYWORD">sub</span> b { <span class="highlite-KEYWORD">return</span> }; b().<span class="highlite-ROUTINE">say</span>; <span class="highlite-COMMENT"># OUTPUT: «Nil␤» </span><span class="highlite-ROUTINE">say</span> (<span class="highlite-KEYWORD">if</span> 1 { }); <span class="highlite-COMMENT"># OUTPUT: «Nil␤» </span>{ ; }().<span class="highlite-ROUTINE">say</span>; <span class="highlite-COMMENT"># OUTPUT: «Nil␤» </span><span class="highlite-ROUTINE">say</span> <span class="highlite-ROUTINE">EVAL</span> <span class="highlite-STRING_DELIMITER">"</span><span class="highlite-STRING_DELIMITER">"</span>; <span class="highlite-COMMENT"># OUTPUT: «Nil␤»</span></pre> </div> </div> <p>In a list, <code>Nil</code> takes the space of one value. Iterating <code>Nil</code> behaves like iteration of any non-iterable value, producing a sequence of one <code>Nil</code>. (When you need the other meaning, the special value <a href="/type/Slip#constant_Empty">Empty</a> is available to take no spaces when inserted into list, and to return no values when iterated.)</p> <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights">(1<span class="highlite-OPERATOR">,</span> <span class="highlite-TYPE">Nil</span><span class="highlite-OPERATOR">,</span> 3).<span class="highlite-ROUTINE">elems</span>.<span class="highlite-ROUTINE">say</span>; <span class="highlite-COMMENT"># OUTPUT: «3␤» </span>(<span class="highlite-KEYWORD">for</span> <span class="highlite-TYPE">Nil</span> { <span class="highlite-NAME_SCALAR">$_</span> }).<span class="highlite-ROUTINE">raku</span>.<span class="highlite-ROUTINE">say</span>; <span class="highlite-COMMENT"># OUTPUT: «(Nil,)␤»</span></pre> </div> </div> <p>Any method call on <code>Nil</code> of a method that does not exist, and consequently, any subscripting operation, will succeed and return <code>Nil</code>.</p> <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-ROUTINE">say</span> <span class="highlite-TYPE">Nil</span>.ITotallyJustMadeThisUp; <span class="highlite-COMMENT"># OUTPUT: «Nil␤» </span><span class="highlite-ROUTINE">say</span> (<span class="highlite-TYPE">Nil</span>)[100]; <span class="highlite-COMMENT"># OUTPUT: «Nil␤» </span><span class="highlite-ROUTINE">say</span> (<span class="highlite-TYPE">Nil</span>){100}; <span class="highlite-COMMENT"># OUTPUT: «Nil␤»</span></pre> </div> </div> <p><a name="index-entry-Nil_assignment" class="index-entry"></a> When assigned to a <a href="/language/containers">container</a>, the <code>Nil</code> value (but not any subclass of <code>Nil</code>) will attempt to revert the container to its default value; if no such default is declared, Raku assumes <a href="/type/Any"><code>Any</code></a>.</p><p>Since a hash assignment expects two elements, use <code>Empty</code> not <code>Nil</code>, e.g.</p> <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">my</span> <span class="highlite-NAME_HASH">%h</span> <span class="highlite-OPERATOR">=</span> <span class="highlite-STRING_DELIMITER">'</span><span class="highlite-STRING">a</span><span class="highlite-STRING_DELIMITER">'</span>..<span class="highlite-STRING_DELIMITER">'</span><span class="highlite-STRING">b</span><span class="highlite-STRING_DELIMITER">'</span> <span class="highlite-OPERATOR">Z</span>=<span class="highlite-OPERATOR">></span> 1.<span class="highlite-OPERATOR">.*</span>; <span class="highlite-COMMENT"># stuff happens </span><span class="highlite-NAME_HASH">%h</span> <span class="highlite-OPERATOR">=</span> <span class="highlite-TYPE">Empty</span>; <span class="highlite-COMMENT"># %h = Nil will generate an error</span></pre> </div> </div> <p>However, if the container type is constrained with <code>:D</code>, assigning <code>Nil</code> to it will immediately throw an exception. (In contrast, an instantiated <a href="/type/Failure"><code>Failure</code></a> matches <code>:D</code> because it's a definite value, but will fail to match the actual nominal type unless it happens to be a parent class of <a href="/type/Failure"><code>Failure</code></a>.) Native types can not have default values nor hold a type object. Assigning <code>Nil</code> to a native type container will fail with a runtime error.</p> <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">my</span> <span class="highlite-TYPE">Int</span> <span class="highlite-NAME_SCALAR">$x</span> <span class="highlite-OPERATOR">=</span> 42; <span class="highlite-NAME_SCALAR">$x</span> <span class="highlite-OPERATOR">=</span> <span class="highlite-TYPE">Nil</span>; <span class="highlite-NAME_SCALAR">$x</span>.<span class="highlite-ROUTINE">say</span>; <span class="highlite-COMMENT"># OUTPUT: «(Int)␤» </span> <span class="highlite-KEYWORD">sub</span> <span class="highlite-ROUTINE">f</span>( <span class="highlite-KEYWORD">--></span> Int:D ){ <span class="highlite-TYPE">Nil</span> }; <span class="highlite-COMMENT"># this definedness constraint is ignored </span><span class="highlite-KEYWORD">my</span> Int:D <span class="highlite-NAME_SCALAR">$i</span> <span class="highlite-OPERATOR">=</span> <span class="highlite-ROUTINE">f</span>; <span class="highlite-COMMENT"># this definedness constraint is not ignored, so throws </span><span class="highlite-KEYWORD">CATCH</span> { <span class="highlite-KEYWORD">default</span> { <span class="highlite-ROUTINE">put</span> .^<span class="highlite-ROUTINE">name</span><span class="highlite-OPERATOR">,</span> <span class="highlite-STRING_DELIMITER">'</span><span class="highlite-STRING">: </span><span class="highlite-STRING_DELIMITER">'</span><span class="highlite-OPERATOR">,</span> .<span class="highlite-TYPE">Str</span> } }; <span class="highlite-COMMENT"># OUTPUT: «X::TypeCheck::Assignment: Type check failed in assignment to $y; expected Int but got Any (Any)» </span> <span class="highlite-KEYWORD">sub</span> g( <span class="highlite-KEYWORD">--></span> Int:D ){ <span class="highlite-ROUTINE">fail</span> <span class="highlite-STRING_DELIMITER">"</span><span class="highlite-STRING">oops</span><span class="highlite-STRING_DELIMITER">"</span> }; <span class="highlite-COMMENT"># this definedness constraint is ignored </span><span class="highlite-KEYWORD">my</span> Any:D <span class="highlite-NAME_SCALAR">$h</span> <span class="highlite-OPERATOR">=</span> g; <span class="highlite-COMMENT"># failure object matches Any:D, so is assigned</span></pre> </div> </div> <p>but</p> <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">my</span> Int:D <span class="highlite-NAME_SCALAR">$j</span> <span class="highlite-OPERATOR">=</span> g; <span class="highlite-COMMENT"># It will throw both exceptions: </span><span class="highlite-COMMENT"># Earlier failure: </span><span class="highlite-COMMENT"># oops </span><span class="highlite-COMMENT"># in sub g at <unknown file> line 1 </span><span class="highlite-COMMENT"># in block <unit> at <unknown file> line 1 </span><span class="highlite-COMMENT"># </span><span class="highlite-COMMENT"># Final error: </span><span class="highlite-COMMENT"># Type check failed in assignment to $j; expected Int:D but got Failure (Failure.new(exception...) </span><span class="highlite-COMMENT"># in block <unit> at <unknown file> line 1 </span></pre> </div> </div> <p>Because an untyped variable is type <a href="/type/Any"><code>Any</code></a>, assigning a <code>Nil</code> to one will result in an <a href="/type/Any">(Any)</a> type object.</p> <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">my</span> <span class="highlite-NAME_SCALAR">$x</span> <span class="highlite-OPERATOR">=</span> <span class="highlite-TYPE">Nil</span>; <span class="highlite-NAME_SCALAR">$x</span>.<span class="highlite-ROUTINE">say</span>; <span class="highlite-COMMENT"># OUTPUT: «(Any)␤» </span><span class="highlite-KEYWORD">my</span> <span class="highlite-TYPE">Int</span> <span class="highlite-NAME_SCALAR">$y</span> <span class="highlite-OPERATOR">=</span> <span class="highlite-NAME_SCALAR">$x</span>; <span class="highlite-COMMENT"># will throw an exception </span><span class="highlite-KEYWORD">CATCH</span> { <span class="highlite-KEYWORD">default</span> { <span class="highlite-ROUTINE">put</span> .^<span class="highlite-ROUTINE">name</span><span class="highlite-OPERATOR">,</span> <span class="highlite-STRING_DELIMITER">'</span><span class="highlite-STRING">: </span><span class="highlite-STRING_DELIMITER">'</span><span class="highlite-OPERATOR">,</span> .<span class="highlite-TYPE">Str</span> } }; <span class="highlite-COMMENT"># OUTPUT: «X::TypeCheck::Assignment: Type check failed in assignment to $y; expected Int but got Any (Any)␤»</span></pre> </div> </div> <p>If you are looking for a variable which transforms objects into type objects when said variable appears on the right-hand side, you can type the container as <code>Nil</code>.</p> <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">my</span> <span class="highlite-TYPE">Nil</span> <span class="highlite-NAME_SCALAR">$x</span>; <span class="highlite-KEYWORD">my</span> <span class="highlite-TYPE">Str</span> <span class="highlite-NAME_SCALAR">$s</span> <span class="highlite-OPERATOR">=</span> <span class="highlite-NAME_SCALAR">$x</span>; <span class="highlite-NAME_SCALAR">$s</span>.<span class="highlite-ROUTINE">say</span>; <span class="highlite-COMMENT"># OUTPUT: «(Str)␤»</span></pre> </div> </div> <p>There is an important exception to this transforms-into-type-object rule: assigning <code>Nil</code> to a variable which has a default will restore that default.</p> <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">my</span> <span class="highlite-TYPE">Int</span> <span class="highlite-NAME_SCALAR">$x</span> <span class="highlite-KEYWORD">is</span> <span class="highlite-KEYWORD">default</span>(42) <span class="highlite-OPERATOR">=</span> -1; <span class="highlite-KEYWORD">my</span> <span class="highlite-NAME_SCALAR">$y</span> <span class="highlite-OPERATOR">=</span> 1; <span class="highlite-KEYWORD">for</span> <span class="highlite-NAME_SCALAR">$x</span><span class="highlite-OPERATOR">,</span> <span class="highlite-NAME_SCALAR">$y</span> <span class="highlite-KEYWORD">-></span> <span class="highlite-NAME_SCALAR">$val</span> <span class="highlite-KEYWORD">is</span> <span class="highlite-KEYWORD">rw</span> { <span class="highlite-NAME_SCALAR">$val</span> <span class="highlite-OPERATOR">=</span> <span class="highlite-TYPE">Nil</span> <span class="highlite-KEYWORD">unless</span> <span class="highlite-NAME_SCALAR">$val</span> <span class="highlite-OPERATOR">></span> 0 } <span class="highlite-NAME_SCALAR">$x</span>.<span class="highlite-ROUTINE">say</span>; <span class="highlite-COMMENT"># OUTPUT: «42␤»</span></pre> </div> </div> <p>Methods such as <code>BIND-POS</code>, <code>ASSIGN-KEY</code>, <code>ASSIGN-POS</code> will die; <code>BIND-KEY</code> will produce a failure with an <a href="/type/X/Bind"><code>X::Bind</code></a> exception in it, and <code>STORE</code> will produce an <a href="/type/X/Assignment/RO"><code>X::Assignment::RO</code></a> exception.</p> <h1 id="Methods" class="raku-h1"><a href="#class_Nil" title="go to top of document">Methods<a class="raku-anchor" title="direct link" href="#Methods">§</a></a></h1> <h2 id="method_append" class="raku-h2"><a href="#class_Nil" title="go to top of document">method append<a class="raku-anchor" title="direct link" href="#method_append">§</a></a></h2>  <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">method</span> <span class="highlite-ROUTINE">append</span>(<span class="highlite-OPERATOR">*</span>@)</pre> </div> </div> <p>Warns the user that they tried to append onto a <code>Nil</code> (or derived type object).</p> <h2 id="method_gist" class="raku-h2"><a href="#class_Nil" title="go to top of document">method gist<a class="raku-anchor" title="direct link" href="#method_gist">§</a></a></h2>  <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">method</span> <span class="highlite-ROUTINE">gist</span>(<span class="highlite-KEYWORD">--></span> Str:D)</pre> </div> </div> <p>Returns <code>"Nil"</code>.</p> <h2 id="method_Str" class="raku-h2"><a href="#class_Nil" title="go to top of document">method Str<a class="raku-anchor" title="direct link" href="#method_Str">§</a></a></h2>  <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">method</span> <span class="highlite-TYPE">Str</span>()</pre> </div> </div> <p>Warns the user that they tried to stringify a <code>Nil</code>.</p> <h2 id="method_new" class="raku-h2"><a href="#class_Nil" title="go to top of document">method new<a class="raku-anchor" title="direct link" href="#method_new">§</a></a></h2>  <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">method</span> <span class="highlite-ROUTINE">new</span>(<span class="highlite-OPERATOR">*</span>@)</pre> </div> </div> <p>Returns <code>Nil</code></p> <h2 id="method_prepend" class="raku-h2"><a href="#class_Nil" title="go to top of document">method prepend<a class="raku-anchor" title="direct link" href="#method_prepend">§</a></a></h2>  <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">method</span> <span class="highlite-ROUTINE">prepend</span>(<span class="highlite-OPERATOR">*</span>@)</pre> </div> </div> <p>Warns the user that they tried to prepend onto a <code>Nil</code> or derived type object.</p> <h2 id="method_push" class="raku-h2"><a href="#class_Nil" title="go to top of document">method push<a class="raku-anchor" title="direct link" href="#method_push">§</a></a></h2>  <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">method</span> <span class="highlite-ROUTINE">push</span>(<span class="highlite-OPERATOR">*</span>@)</pre> </div> </div> <p>Warns the user that they tried to push onto a <code>Nil</code> or derived type object.</p> <h2 id="method_unshift" class="raku-h2"><a href="#class_Nil" title="go to top of document">method unshift<a class="raku-anchor" title="direct link" href="#method_unshift">§</a></a></h2>  <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">method</span> <span class="highlite-ROUTINE">unshift</span>(<span class="highlite-OPERATOR">*</span>@)</pre> </div> </div> <p>Warns the user that they tried to unshift onto a <code>Nil</code> or derived type object.</p> <h2 id="method_ords" class="raku-h2"><a href="#class_Nil" title="go to top of document">method ords<a class="raku-anchor" title="direct link" href="#method_ords">§</a></a></h2>  <p>Returns an empty <a href="/type/Seq"><code>Seq</code></a>, but will also issue a warning depending on the context it's used (for instance, a warning about using it in string context if used with <code>say</code>).</p> <h2 id="method_chrs" class="raku-h2"><a href="#class_Nil" title="go to top of document">method chrs<a class="raku-anchor" title="direct link" href="#method_chrs">§</a></a></h2>  <p>Will return <code>\0</code>, and also throw a warning.</p> <h2 id="method_FALLBACK" class="raku-h2"><a href="#class_Nil" title="go to top of document">method FALLBACK<a class="raku-anchor" title="direct link" href="#method_FALLBACK">§</a></a></h2>  <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">method</span> <span class="highlite-ROUTINE">FALLBACK</span>(<span class="highlite-OPERATOR">|</span> <span class="highlite-KEYWORD">--></span> <span class="highlite-TYPE">Nil</span>) {}</pre> </div> </div> <p>The <a href="/language/typesystem#index-entry-FALLBACK_(method)">fallback method</a> takes any arguments and always returns a <code>Nil</code>.</p> <h2 id="method_Numeric" class="raku-h2"><a href="#class_Nil" title="go to top of document">method Numeric<a class="raku-anchor" title="direct link" href="#method_Numeric">§</a></a></h2>  <div class="raku-code raku-lang"> <button class="copy-code" title="Copy code"><i class="far fa-clipboard"></i></button> <label>Raku highlighting</label> <div> <pre class="nohighlights"><span class="highlite-KEYWORD">method</span> <span class="highlite-TYPE">Numeric</span>()</pre> </div> </div> <p>Warns the user that they tried to numify a <code>Nil</code>.</p> <h1 id="typegraphrelations" class="raku-h1"><a href="#" title="go to top of document">Typegraph<a class="raku-anchor" title="direct link" href="#typegraphrelations">§</a></a></h1> <figure class="typegraph" > <figcaption>Type relations for <code>Nil</code></figcaption> <svg width="89pt" height="332pt" viewBox="0.00 0.00 88.59 332.00" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> <g id="graph0" class="graph" transform="scale(1 1) rotate(0) translate(4 328)"> <title>raku-type-graph</title> <polygon fill="#ffffff" stroke="transparent" points="-4,4 -4,-328 84.59,-328 84.59,4 -4,4"/>  <g id="node1" class="node"> <title>Nil</title> <g id="a_node1"><a xlink:href="/type/Nil" xlink:title="Nil"> <ellipse fill="none" stroke="#000000" cx="40.3" cy="-90" rx="27" ry="18"/> <text text-anchor="middle" x="40.3" y="-86.3" font-family="FreeSans" font-size="14.00" fill="#000000">Nil</text> </a> </g> </g>  <g id="node4" class="node"> <title>Cool</title> <g id="a_node4"><a xlink:href="/type/Cool" xlink:title="Cool"> <ellipse fill="none" stroke="#000000" cx="40.3" cy="-162" rx="30.59" ry="18"/> <text text-anchor="middle" x="40.3" y="-158.3" font-family="FreeSans" font-size="14.00" fill="#000000">Cool</text> </a> </g> </g>  <g id="edge1" class="edge"> <title>Nil->Cool</title> <path fill="none" stroke="#000000" d="M40.3,-108.3C40.3,-116.02 40.3,-125.29 40.3,-133.89"/> <polygon fill="#000000" stroke="#000000" points="36.8,-133.9 40.3,-143.9 43.8,-133.9 36.8,-133.9"/> </g>  <g id="node2" class="node"> <title>Mu</title> <g id="a_node2"><a xlink:href="/type/Mu" xlink:title="Mu"> <ellipse fill="none" stroke="#000000" cx="40.3" cy="-306" rx="27" ry="18"/> <text text-anchor="middle" x="40.3" y="-302.3" font-family="FreeSans" font-size="14.00" fill="#000000">Mu</text> </a> </g> </g>  <g id="node3" class="node"> <title>Any</title> <g id="a_node3"><a xlink:href="/type/Any" xlink:title="Any"> <ellipse fill="none" stroke="#000000" cx="40.3" cy="-234" rx="28.7" ry="18"/> <text text-anchor="middle" x="40.3" y="-230.3" font-family="FreeSans" font-size="14.00" fill="#000000">Any</text> </a> </g> </g>  <g id="edge2" class="edge"> <title>Any->Mu</title> <path fill="none" stroke="#000000" d="M40.3,-252.3C40.3,-260.02 40.3,-269.29 40.3,-277.89"/> <polygon fill="#000000" stroke="#000000" points="36.8,-277.9 40.3,-287.9 43.8,-277.9 36.8,-277.9"/> </g>  <g id="edge3" class="edge"> <title>Cool->Any</title> <path fill="none" stroke="#000000" d="M40.3,-180.3C40.3,-188.02 40.3,-197.29 40.3,-205.89"/> <polygon fill="#000000" stroke="#000000" points="36.8,-205.9 40.3,-215.9 43.8,-205.9 36.8,-205.9"/> </g>  <g id="node5" class="node"> <title>Failure</title> <g id="a_node5"><a xlink:href="/type/Failure" xlink:title="Failure"> <ellipse fill="none" stroke="#000000" cx="40.3" cy="-18" rx="40.09" ry="18"/> <text text-anchor="middle" x="40.3" y="-14.3" font-family="FreeSans" font-size="14.00" fill="#000000">Failure</text> </a> </g> </g>  <g id="edge4" class="edge"> <title>Failure->Nil</title> <path fill="none" stroke="#000000" d="M40.3,-36.3C40.3,-44.02 40.3,-53.29 40.3,-61.89"/> <polygon fill="#000000" stroke="#000000" points="36.8,-61.9 40.3,-71.9 43.8,-61.9 36.8,-61.9"/> </g> </g> </svg> <p class="fallback"> <a rel="alternate" href="/assets/typegraphs/Nil.svg"> Expand chart above </a></p> </figure> </div></div></section> </div> </div> </div> <footer class="footer main-footer"> <div class="container px-4"> <nav class="level"> <div class="level-left"> <div class="level-item"> <a href="/about">About</a> </div> <div class="level-item"> <a id="toggle-theme">Toggle theme</a> </div> <div class="level-item" title="fc2dc4a42 2024-05-19"> <a>Commit</a> </div> </div> <div class="level-right"> <div class="level-item"> <a href="/license">License</a> </div> </div> </nav> </div> </footer> </body> </html>

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class Nil | Raku Documentation