Common Lispの多値とその実装達 2018-11-15 言語処理系 言語実装 Lisp Common Lisp # Common Lispの多値とその実装達 ---------------------- [言語処理系勉強会 Vol.1 - connpass](https://connpass.com/event/104863/) <!-- .slide: class="center" --> === # About Me ---------  <!-- .element: style="position:absolute;right:0;z-index:-1" width="20%" --> * κeen * [@blackenedgold](https://twitter.com/blackenedgold) * Github: [KeenS](https://github.com/KeenS) * [Idein Inc.](https://idein.jp/)のエンジニア * Lisp, ML, Rust, Shell Scriptあたりを書きます === # 今日話すこと -------------- * 多値のこと * Common Lispの多値のこと * Common Lispの多値の実装のこと === # 引数と返り値の数 ----------------- <style> .border-table { width: 100%; height: 100%; } .border-table tr, .border-table td, .border-table th { border: solid 1px #000; } </style> <table class="border-table"> <tr><td colspan=2 rowspan=2></td><th colspan=2>引数</th></tr> <tr> <th>単</th><th>複</th></tr> <tr><th rowspan=2>返り値</th><th>単</th><td>MLなど</td><td>多数</td></tr> <tr> <th>複</th><td>???</td><td>Lispなど</td></tr> </table> <p>===</p> <h1 id="mlの引数">MLの引数</h1> <hr> <ul> <li>複数引数に見えるがタプルを1つ取っている</li> </ul> <pre tabindex="0"><code class="language-standard-ml" data-lang="standard-ml">fun foo(v1, v2) = v1 + v2 </code></pre><ul> <li>複数引数と違うの？ <ul> <li>違う</li> <li>いい悪いではなく違う。</li> </ul> </li> </ul> <pre tabindex="0"><code class="language-standard-ml" data-lang="standard-ml">val tuple = (1, 2) foo tuple (* -> 3 *) </code></pre><p>===</p> <h1 id="lispの多値">Lispの多値</h1> <hr> <ul> <li>複数の値を返せる</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="nv">CL-USER></span> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span> <span class="mi">2</span><span class="p">)</span> </span></span><span class="line"><span class="cl"><span class="mi">1</span> </span></span><span class="line"><span class="cl"><span class="mi">2</span> </span></span></code></pre></div><ul> <li>タプルと違うの？ <ul> <li>違う</li> <li>いい悪いではなく違う。</li> </ul> </li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="nv">CL-USER></span> <span class="p">(</span><span class="nf">identity</span> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span> <span class="mi">2</span><span class="p">))</span> </span></span><span class="line"><span class="cl"><span class="mi">1</span> </span></span></code></pre></div><p>===</p> <h1 id="多値でないもの">多値でないもの</h1> <hr> <ul> <li>rubyの配列の分配束縛</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-ruby" data-lang="ruby"><span class="line"><span class="cl"><span class="n">irb</span><span class="p">(</span><span class="n">main</span><span class="p">):</span><span class="mo">001</span><span class="p">:</span><span class="mi">0</span><span class="o">></span> <span class="n">v1</span><span class="p">,</span> <span class="n">v2</span> <span class="o">=</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">2</span> <span class="c1"># [v1, v2] = [1, 2]</span> </span></span><span class="line"><span class="cl"><span class="o">=></span> <span class="o">[</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="o">]</span> </span></span><span class="line"><span class="cl"><span class="n">irb</span><span class="p">(</span><span class="n">main</span><span class="p">):</span><span class="mo">002</span><span class="p">:</span><span class="mi">0</span><span class="o">></span> <span class="n">v1</span> </span></span><span class="line"><span class="cl"><span class="o">=></span> <span class="mi">1</span> </span></span><span class="line"><span class="cl"><span class="n">irb</span><span class="p">(</span><span class="n">main</span><span class="p">):</span><span class="mo">003</span><span class="p">:</span><span class="mi">0</span><span class="o">></span> <span class="n">v2</span> </span></span><span class="line"><span class="cl"><span class="o">=></span> <span class="mi">2</span> </span></span></code></pre></div><p>===</p> <h1 id="多値でないもの-1">多値でないもの</h1> <hr> <ul> <li>Pythonのタプルの分配束縛</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-python" data-lang="python"><span class="line"><span class="cl"><span class="o">>>></span> <span class="n">v1</span><span class="p">,</span> <span class="n">v2</span> <span class="o">=</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">2</span> <span class="c1"># (v1, v2) = (1, 2)</span> </span></span><span class="line"><span class="cl"><span class="o">>>></span> <span class="n">v1</span> </span></span><span class="line"><span class="cl"><span class="mi">1</span> </span></span><span class="line"><span class="cl"><span class="o">>>></span> <span class="n">v2</span> </span></span><span class="line"><span class="cl"><span class="mi">2</span> </span></span></code></pre></div><p>===</p> <h1 id="common-lispの多値">Common Lispの多値</h1> <hr> <ul> <li>特徴的な挙動をみていく</li> <li>非常に一貫した挙動になっている</li> </ul> <p>===</p> <h1 id="多値を返す">多値を返す</h1> <hr> <ul> <li>標準関数の <code>VALUES</code> を使う</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="nv">CL-USER></span> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span> <span class="mi">2</span><span class="p">)</span> </span></span><span class="line"><span class="cl"><span class="mi">1</span> </span></span><span class="line"><span class="cl"><span class="mi">2</span> </span></span></code></pre></div><p>===</p> <h1 id="多値を受け取る">多値を受け取る</h1> <hr> <ul> <li>専用の構文(スペシャルフォーム)で関数の引数に渡せる</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="k">multiple-value-call</span> <span class="nf">#'+</span> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span> <span class="mi">2</span><span class="p">))</span> </span></span><span class="line"><span class="cl"><span class="c1">; -> 3</span> </span></span></code></pre></div><p>===</p> <h1 id="多値に束縛する">多値に束縛する</h1> <hr> <ul> <li>マクロでできる</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="nb">multiple-value-bind</span> <span class="p">(</span><span class="nv">v1</span> <span class="nv">v2</span><span class="p">)</span> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span> <span class="mi">2</span><span class="p">)</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nf">+</span> <span class="nv">v1</span> <span class="nv">v2</span><span class="p">))</span> </span></span><span class="line"><span class="cl"><span class="c1">; -> 3</span> </span></span></code></pre></div><p>===</p> <h1 id="ダイナミックに多値">ダイナミックに多値</h1> <hr> <ul> <li>動的な言語なので多値の数を変えるのも可能</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="nb">defun</span> <span class="nv">dynamic-mv</span> <span class="p">(</span><span class="nv">x</span><span class="p">)</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nb">case</span> <span class="nv">x</span> </span></span><span class="line"><span class="cl"> <span class="p">((</span><span class="mi">1</span><span class="p">)</span> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span><span class="p">))</span> </span></span><span class="line"><span class="cl"> <span class="p">((</span><span class="mi">2</span><span class="p">)</span> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span> <span class="mi">2</span><span class="p">))</span> </span></span><span class="line"><span class="cl"> <span class="p">((</span><span class="mi">3</span><span class="p">)</span> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span> <span class="mi">2</span> <span class="mi">3</span><span class="p">))</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nv">otherwise</span> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span> <span class="mi">2</span> <span class="mi">3</span> <span class="mi">4</span><span class="p">))))</span> </span></span></code></pre></div><p>===</p> <h1 id="ダイナミックに多値-1">ダイナミックに多値</h1> <hr> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="nv">CL-USER></span> <span class="p">(</span><span class="nv">dynamic-mv</span> <span class="mi">1</span><span class="p">)</span> </span></span><span class="line"><span class="cl"><span class="mi">1</span> </span></span><span class="line"><span class="cl"><span class="nv">CL-USER></span> <span class="p">(</span><span class="nv">dynamic-mv</span> <span class="mi">2</span><span class="p">)</span> </span></span><span class="line"><span class="cl"><span class="mi">1</span> </span></span><span class="line"><span class="cl"><span class="mi">2</span> </span></span><span class="line"><span class="cl"><span class="nv">CL-USER></span> <span class="p">(</span><span class="nv">dynamic-mv</span> <span class="mi">3</span><span class="p">)</span> </span></span><span class="line"><span class="cl"><span class="mi">1</span> </span></span><span class="line"><span class="cl"><span class="mi">2</span> </span></span><span class="line"><span class="cl"><span class="mi">3</span> </span></span></code></pre></div><p>===</p> <h1 id="少なく受け取る">少なく受け取る</h1> <hr> <ul> <li>無言で無視できる</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="nb">multiple-value-bind</span> <span class="p">(</span><span class="nv">v1</span> <span class="nv">v2</span><span class="p">)</span> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span> <span class="mi">2</span> <span class="mi">3</span><span class="p">)</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nf">+</span> <span class="nv">v1</span> <span class="nv">v2</span><span class="p">))</span> </span></span></code></pre></div><p>===</p> <h1 id="単値で受け取る">単値で受け取る</h1> <hr> <ul> <li>もちろんできる <ul> <li>「少なく受け取る」の自然な流れ</li> </ul> </li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="k">let</span> <span class="p">((</span><span class="nv">v</span> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span> <span class="mi">2</span> <span class="mi">3</span><span class="p">)))</span> </span></span><span class="line"><span class="cl"> <span class="nv">v</span><span class="p">)</span> </span></span><span class="line"><span class="cl"><span class="c1">; -> 1</span> </span></span></code></pre></div><p>===</p> <h1 id="多く受け取る">多く受け取る</h1> <hr> <ul> <li>nilが入る</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="nb">multiple-value-bind</span> <span class="p">(</span><span class="nv">v1</span> <span class="nv">v2</span> <span class="nv">v3</span><span class="p">)</span> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span> <span class="mi">2</span><span class="p">)</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nc">list</span> <span class="nv">v1</span> <span class="nv">v2</span> <span class="nv">v3</span><span class="p">))</span> </span></span><span class="line"><span class="cl"><span class="c1">; -> (1 2 NIL)</span> </span></span></code></pre></div><p>===</p> <h1 id="零値">零値</h1> <hr> <ul> <li>値を0個返すこともできる</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="nv">CL-USER></span> <span class="p">(</span><span class="nf">values</span><span class="p">)</span> </span></span><span class="line"><span class="cl"><span class="c1">; No value</span> </span></span></code></pre></div><p>===</p> <h1 id="零値を受け取る">零値を受け取る</h1> <hr> <ul> <li>nilが入る <ul> <li>「多く受け取る」の自然な流れ</li> </ul> </li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="k">let</span> <span class="p">((</span><span class="nv">v</span> <span class="p">(</span><span class="nf">values</span><span class="p">)))</span> </span></span><span class="line"><span class="cl"> <span class="nv">v</span><span class="p">)</span> </span></span><span class="line"><span class="cl"><span class="c1">; -> NIL</span> </span></span></code></pre></div><p>===</p> <h1 id="標準ライブラリ">標準ライブラリ</h1> <hr> <ul> <li>ハッシュテーブル</li> <li>2値目にキーが存在したかが入る <ul> <li>1値目は存在しなかったらnil</li> </ul> </li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="k">let</span> <span class="p">((</span><span class="nv">hash</span> <span class="p">(</span><span class="nf">make-hash-table</span><span class="p">)))</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nb">setf</span> <span class="p">(</span><span class="nf">gethash</span> <span class="ss">:nil</span> <span class="nv">hash</span><span class="p">)</span> <span class="no">nil</span><span class="p">)</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nf">gethash</span> <span class="ss">:nil</span> <span class="nv">hash</span><span class="p">))</span> </span></span><span class="line"><span class="cl"><span class="c1">; -> NIL</span> </span></span><span class="line"><span class="cl"><span class="c1">; -> T</span> </span></span></code></pre></div><p>===</p> <h1 id="標準ライブラリ-1">標準ライブラリ</h1> <hr> <ul> <li>ハッシュテーブルの次があるか、キー、値が多値で返る</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="k">let</span> <span class="p">((</span><span class="nv">hash</span> <span class="p">(</span><span class="nf">make-hash-table</span><span class="p">)))</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nb">setf</span> <span class="p">(</span><span class="nf">gethash</span> <span class="ss">:nil</span> <span class="nv">hash</span><span class="p">)</span> <span class="no">nil</span><span class="p">)</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nb">with-hash-table-iterator</span> <span class="p">(</span><span class="nv">next</span> <span class="nv">hash</span><span class="p">)</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nb">loop</span> </span></span><span class="line"><span class="cl"> <span class="c1">; ここ</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nb">multiple-value-bind</span> <span class="p">(</span><span class="nv">more</span> <span class="nv">key</span> <span class="nv">value</span><span class="p">)</span> <span class="p">(</span><span class="nv">next</span><span class="p">)</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nb">unless</span> <span class="nv">more</span> <span class="p">(</span><span class="nb">return</span> <span class="no">nil</span><span class="p">))</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nf">print</span> <span class="p">(</span><span class="nc">list</span> <span class="nv">key</span> <span class="nv">value</span><span class="p">))))))</span> </span></span></code></pre></div><p>===</p> <h1 id="激しい例">激しい例</h1> <hr> <ul> <li><code>sb-unix:unix-getrusage</code></li> <li>SBCLの処理系拡張のUNIX API</li> <li>まずは手元で <code>man 2 getrusage</code> してみて</li> <li>いくよ…</li> </ul> <p>===</p> <h1 id="激しい例-1">激しい例</h1> <hr> <ul> <li>多値が16個返る</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="nv">sb-unix:unix-getrusage</span> <span class="nv">sb-unix:rusage_self</span><span class="p">)</span> </span></span><span class="line"><span class="cl"><span class="c1">;; T</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 650886</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 69591</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 547536</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 0</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 0</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 0</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 35833</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 0</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 0</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 16</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 480</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 0</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 0</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 0</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 507</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 78</span> </span></span></code></pre></div><p>===</p> <h1 id="common-lisp小話">Common Lisp小話</h1> <hr> <ul> <li><code>eval</code> 関数がある <ul> <li>実行時にインタプリタが呼べる</li> </ul> </li> <li><code>compile</code> 関数がある <ul> <li>実行時にコンパイラが呼べる</li> </ul> </li> <li><code>disassemble</code> 関数がある <ul> <li>実行時にディスアセンブラが呼べる</li> </ul> </li> <li>ダイナミック!!</li> </ul> <p>===</p> <h1 id="common-lisp小話-1">Common Lisp小話</h1> <hr> <ul> <li>2行でJITが書ける</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="nf">eval</span> <span class="o">'</span><span class="p">(</span><span class="nb">defun</span> <span class="nv">inc</span> <span class="p">(</span><span class="nv">x</span><span class="p">)</span> <span class="p">(</span><span class="nf">1+</span> <span class="nv">x</span><span class="p">)))</span> </span></span><span class="line"><span class="cl"><span class="p">(</span><span class="nf">compile</span> <span class="ss">'inc</span><span class="p">)</span> </span></span></code></pre></div><p>===</p> <h1 id="common-lisp小話-2">Common Lisp小話</h1> <hr> <ul> <li>さらに即座にディスアセンブルできる</li> </ul> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="nf">disassemble</span> <span class="nf">#'</span><span class="nv">inc</span><span class="p">)</span> </span></span><span class="line"><span class="cl"><span class="c1">; disassembly for INC</span> </span></span><span class="line"><span class="cl"><span class="c1">; Size: 35 bytes. Origin: #x100209ED64</span> </span></span><span class="line"><span class="cl"><span class="c1">; 64: 498B4D60 MOV RCX, [R13+96] ; no-arg-parsing entry point</span> </span></span><span class="line"><span class="cl"> <span class="c1">; thread.binding-stack-pointer</span> </span></span><span class="line"><span class="cl"><span class="c1">; 68: 48894DF8 MOV [RBP-8], RCX</span> </span></span><span class="line"><span class="cl"><span class="c1">;;;; GCのタグがあるので1bitシフトされてる</span> </span></span><span class="line"><span class="cl"><span class="c1">; 6C: BF02000000 MOV EDI, 2</span> </span></span><span class="line"><span class="cl"><span class="c1">; 71: 488BD3 MOV RDX, RBX</span> </span></span><span class="line"><span class="cl"><span class="c1">; 74: FF1425A800B021 CALL QWORD PTR [#x21B000A8] ; GENERIC-+</span> </span></span><span class="line"><span class="cl"><span class="c1">; 7B: 488B5DF0 MOV RBX, [RBP-16]</span> </span></span><span class="line"><span class="cl"><span class="c1">; 7F: 488BE5 MOV RSP, RBP</span> </span></span><span class="line"><span class="cl"><span class="c1">; 82: F8 CLC</span> </span></span><span class="line"><span class="cl"><span class="c1">; 83: 5D POP RBP</span> </span></span><span class="line"><span class="cl"><span class="c1">; 84: C3 RET</span> </span></span><span class="line"><span class="cl"><span class="c1">; 85: CC0F BREAK 15 ; Invalid argument count trap</span> </span></span></code></pre></div><p>===</p> <h1 id="多値の実装">多値の実装</h1> <hr> <ul> <li>disassemble関数を使って多値の実装を見てみよう</li> <li>複数の処理系で比べるよ</li> <li>Steel Bank Common Lisp (SBCL): ネイティブコンパイル、レジスタマシン</li> <li>GNU CLISP (CLISP): バイトコード、スタックマシン</li> </ul> <p>===</p> <h1 id="単値を返す">単値を返す</h1> <hr> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="nb">defun</span> <span class="nv">one-value</span> <span class="p">()</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span><span class="p">))</span> </span></span></code></pre></div><p>===</p> <h1 id="単値を返す-1">単値を返す</h1> <hr> <p>CLISP</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-text" data-lang="text"><span class="line"><span class="cl">Disassembly of function ONE-VALUE </span></span><span class="line"><span class="cl">(CONST 0) = 1 </span></span><span class="line"><span class="cl">0 required arguments </span></span><span class="line"><span class="cl">0 optional arguments </span></span><span class="line"><span class="cl">No rest parameter </span></span><span class="line"><span class="cl">No keyword parameters </span></span><span class="line"><span class="cl">2 byte-code instructions: </span></span><span class="line"><span class="cl">0 (CONST 0) ; 1 </span></span><span class="line"><span class="cl">1 (SKIP&RET 1) </span></span></code></pre></div><p>===</p> <h1 id="単値を返す-2">単値を返す</h1> <hr> <p>SBCL</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="c1">; disassembly for ONE-VALUE</span> </span></span><span class="line"><span class="cl"><span class="c1">; Size: 21 bytes. Origin: #x2278662C</span> </span></span><span class="line"><span class="cl"><span class="c1">; 2C: 498B4D60 MOV RCX, [R13+96] ; no-arg-parsing entry point</span> </span></span><span class="line"><span class="cl"> <span class="c1">; thread.binding-stack-pointer</span> </span></span><span class="line"><span class="cl"><span class="c1">; 30: 48894DF8 MOV [RBP-8], RCX</span> </span></span><span class="line"><span class="cl"><span class="c1">; 34: BA02000000 MOV EDX, 2</span> </span></span><span class="line"><span class="cl"><span class="c1">; 39: 488BE5 MOV RSP, RBP</span> </span></span><span class="line"><span class="cl"><span class="c1">; 3C: F8 CLC</span> </span></span><span class="line"><span class="cl"><span class="c1">; 3D: 5D POP RBP</span> </span></span><span class="line"><span class="cl"><span class="c1">; 3E: C3 RET</span> </span></span><span class="line"><span class="cl"><span class="c1">; 3F: CC0F BREAK 15 ; Invalid argument count trap</span> </span></span></code></pre></div><p>===</p> <h1 id="多値を返す-1">多値を返す</h1> <hr> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="nb">defun</span> <span class="nv">two-values</span> <span class="p">()</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nf">values</span> <span class="mi">1</span> <span class="mi">2</span><span class="p">))</span> </span></span><span class="line"><span class="cl"> </span></span><span class="line"><span class="cl"><span class="p">(</span><span class="nf">disassemble</span> <span class="nf">#'</span><span class="nv">two-values</span><span class="p">)</span> </span></span></code></pre></div><p>===</p> <h1 id="多値を返す-2">多値を返す</h1> <hr> <p>CLISP</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-text" data-lang="text"><span class="line"><span class="cl">(CONST 0) = 1 </span></span><span class="line"><span class="cl">(CONST 1) = 2 </span></span><span class="line"><span class="cl">0 required arguments </span></span><span class="line"><span class="cl">0 optional arguments </span></span><span class="line"><span class="cl">No rest parameter </span></span><span class="line"><span class="cl">No keyword parameters </span></span><span class="line"><span class="cl">4 byte-code instructions: </span></span><span class="line"><span class="cl">0 (CONST&PUSH 0) ; 1 </span></span><span class="line"><span class="cl">1 (CONST&PUSH 1) ; 2 </span></span><span class="line"><span class="cl">2 (STACK-TO-MV 2) </span></span><span class="line"><span class="cl">4 (SKIP&RET 1) </span></span></code></pre></div><p>===</p> <h1 id="多値を返す-3">多値を返す</h1> <hr> <p>SBCL</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="c1">; disassembly for TWO-VALUE</span> </span></span><span class="line"><span class="cl"><span class="c1">; Size: 40 bytes. Origin: #x2278637C</span> </span></span><span class="line"><span class="cl"><span class="c1">; 7C: 498B4D60 MOV RCX, [R13+96] ; no-arg-parsing entry point</span> </span></span><span class="line"><span class="cl"> <span class="c1">; thread.binding-stack-pointer</span> </span></span><span class="line"><span class="cl"><span class="c1">; 80: 48894DF8 MOV [RBP-8], RCX</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 1</span> </span></span><span class="line"><span class="cl"><span class="c1">; 84: BA02000000 MOV EDX, 2</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 2</span> </span></span><span class="line"><span class="cl"><span class="c1">; 89: BF04000000 MOV EDI, 4</span> </span></span><span class="line"><span class="cl"><span class="c1">; 8E: 488D5D10 LEA RBX, [RBP+16]</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 多値の数</span> </span></span><span class="line"><span class="cl"><span class="c1">; 92: B904000000 MOV ECX, 4</span> </span></span><span class="line"><span class="cl"><span class="c1">;; 恐らく多めに受け取ったときのためにNILで埋めてる</span> </span></span><span class="line"><span class="cl"><span class="c1">; 97: BE17001020 MOV ESI, #x20100017 ; NIL</span> </span></span><span class="line"><span class="cl"><span class="c1">;; キャリーフラグで多値であることを伝える</span> </span></span><span class="line"><span class="cl"><span class="c1">; 9C: F9 STC</span> </span></span><span class="line"><span class="cl"><span class="c1">; 9D: 488BE5 MOV RSP, RBP</span> </span></span><span class="line"><span class="cl"><span class="c1">; A0: 5D POP RBP</span> </span></span><span class="line"><span class="cl"><span class="c1">; A1: C3 RET</span> </span></span><span class="line"><span class="cl"><span class="c1">; A2: CC0F BREAK 15 ; Invalid argument count trap</span> </span></span></code></pre></div><p>===</p> <h1 id="多値を返す-4">多値を返す</h1> <hr> <p>SBCL (3値)</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="c1">; disassembly for THREE-VALUES</span> </span></span><span class="line"><span class="cl"><span class="c1">; Size: 40 bytes. Origin: #x2278640C</span> </span></span><span class="line"><span class="cl"><span class="c1">; 0C: 498B4D60 MOV RCX, [R13+96] ; no-arg-parsing entry point</span> </span></span><span class="line"><span class="cl"> <span class="c1">; thread.binding-stack-pointer</span> </span></span><span class="line"><span class="cl"><span class="c1">; 10: 48894DF8 MOV [RBP-8], RCX</span> </span></span><span class="line"><span class="cl"><span class="c1">; 14: BA02000000 MOV EDX, 2</span> </span></span><span class="line"><span class="cl"><span class="c1">; 19: BF04000000 MOV EDI, 4</span> </span></span><span class="line"><span class="cl"><span class="c1">; 1E: BE06000000 MOV ESI, 6</span> </span></span><span class="line"><span class="cl"><span class="c1">; 23: 488D5D10 LEA RBX, [RBP+16]</span> </span></span><span class="line"><span class="cl"><span class="c1">; 27: B906000000 MOV ECX, 6</span> </span></span><span class="line"><span class="cl"><span class="c1">; 2C: F9 STC</span> </span></span><span class="line"><span class="cl"><span class="c1">; 2D: 488BE5 MOV RSP, RBP</span> </span></span><span class="line"><span class="cl"><span class="c1">; 30: 5D POP RBP</span> </span></span><span class="line"><span class="cl"><span class="c1">; 31: C3 RET</span> </span></span><span class="line"><span class="cl"><span class="c1">; 32: CC0F BREAK 15 ; Invalid argument count trap</span> </span></span></code></pre></div><p>===</p> <h1 id="多値を返す-5">多値を返す</h1> <hr> <p>SBCL (4値) レジスタが溢れた</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="c1">; disassembly for FOUR-VALUES</span> </span></span><span class="line"><span class="cl"><span class="c1">; Size: 55 bytes. Origin: #x2278649C</span> </span></span><span class="line"><span class="cl"><span class="c1">; 9C: 498B4D60 MOV RCX, [R13+96] ; no-arg-parsing entry point</span> </span></span><span class="line"><span class="cl"> <span class="c1">; thread.binding-stack-pointer</span> </span></span><span class="line"><span class="cl"><span class="c1">; A0: 48894DF8 MOV [RBP-8], RCX</span> </span></span><span class="line"><span class="cl"><span class="c1">; A4: BA02000000 MOV EDX, 2</span> </span></span><span class="line"><span class="cl"><span class="c1">; A9: BF04000000 MOV EDI, 4</span> </span></span><span class="line"><span class="cl"><span class="c1">; AE: BE06000000 MOV ESI, 6</span> </span></span><span class="line"><span class="cl"><span class="c1">; B3: 48C745F008000000 MOV QWORD PTR [RBP-16], 8</span> </span></span><span class="line"><span class="cl"><span class="c1">; BB: 488D5D10 LEA RBX, [RBP+16]</span> </span></span><span class="line"><span class="cl"><span class="c1">; BF: B908000000 MOV ECX, 8</span> </span></span><span class="line"><span class="cl"><span class="c1">; C4: F9 STC</span> </span></span><span class="line"><span class="cl"><span class="c1">; C5: 488D65F0 LEA RSP, [RBP-16]</span> </span></span><span class="line"><span class="cl"><span class="c1">; C9: 488B6D00 MOV RBP, [RBP]</span> </span></span><span class="line"><span class="cl"><span class="c1">; CD: FF73F8 PUSH QWORD PTR [RBX-8]</span> </span></span><span class="line"><span class="cl"><span class="c1">; D0: C3 RET</span> </span></span><span class="line"><span class="cl"><span class="c1">; D1: CC0F BREAK 15 ; Invalid argument count trap</span> </span></span></code></pre></div><p>===</p> <h1 id="多値を受け取る-1">多値を受け取る</h1> <hr> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="p">(</span><span class="nb">defun</span> <span class="nv">recieve2-two-values</span> <span class="p">()</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nb">multiple-value-bind</span> <span class="p">(</span><span class="nv">v1</span> <span class="nv">v2</span><span class="p">)</span> <span class="p">(</span><span class="nv">two-values</span><span class="p">)</span> </span></span><span class="line"><span class="cl"> <span class="p">(</span><span class="nf">+</span> <span class="nv">v1</span> <span class="nv">v2</span><span class="p">)))</span> </span></span></code></pre></div><p>===</p> <h1 id="多値を受け取る-2">多値を受け取る</h1> <hr> <p>CLISP</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-text" data-lang="text"><span class="line"><span class="cl">Disassembly of function RECIEVE2-TWO-VALUES </span></span><span class="line"><span class="cl">(CONST 0) = TWO-VALUES </span></span><span class="line"><span class="cl">0 required arguments </span></span><span class="line"><span class="cl">0 optional arguments </span></span><span class="line"><span class="cl">No rest parameter </span></span><span class="line"><span class="cl">No keyword parameters </span></span><span class="line"><span class="cl">6 byte-code instructions: </span></span><span class="line"><span class="cl">0 (CALL0 0) ; TWO-VALUES </span></span><span class="line"><span class="cl">2 (NV-TO-STACK 2) </span></span><span class="line"><span class="cl">4 (LOAD&PUSH 1) </span></span><span class="line"><span class="cl">5 (LOAD&PUSH 1) </span></span><span class="line"><span class="cl">6 (CALLSR 2 55) ; + </span></span><span class="line"><span class="cl">9 (SKIP&RET 3) </span></span></code></pre></div><p>===</p> <h1 id="多値を受け取る-3">多値を受け取る</h1> <hr> <p>SBCL</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-common-lisp" data-lang="common-lisp"><span class="line"><span class="cl"><span class="c1">; disassembly for RECIEVE2-TWO-VALUES</span> </span></span><span class="line"><span class="cl"><span class="c1">; Size: 52 bytes. Origin: #x227867FC</span> </span></span><span class="line"><span class="cl"><span class="c1">; 7FC: 498B4D60 MOV RCX, [R13+96] ; no-arg-parsing entry point</span> </span></span><span class="line"><span class="cl"> <span class="c1">; thread.binding-stack-pointer</span> </span></span><span class="line"><span class="cl"><span class="c1">; 800: 48894DF8 MOV [RBP-8], RCX</span> </span></span><span class="line"><span class="cl"><span class="c1">; 804: 4883EC10 SUB RSP, 16</span> </span></span><span class="line"><span class="cl"><span class="c1">; 808: 31C9 XOR ECX, ECX</span> </span></span><span class="line"><span class="cl"><span class="c1">; 80A: 48892C24 MOV [RSP], RBP</span> </span></span><span class="line"><span class="cl"><span class="c1">; 80E: 488BEC MOV RBP, RSP</span> </span></span><span class="line"><span class="cl"><span class="c1">; 811: E86217D8FD CALL #x20507F78 ; #<FDEFN TWO-VALUES></span> </span></span><span class="line"><span class="cl"><span class="c1">;; キャリーフラグで分岐</span> </span></span><span class="line"><span class="cl"><span class="c1">; 816: 7208 JB L0</span> </span></span><span class="line"><span class="cl"><span class="c1">; 818: BF17001020 MOV EDI, #x20100017 ; NIL</span> </span></span><span class="line"><span class="cl"><span class="c1">; 81D: 488BDC MOV RBX, RSP</span> </span></span><span class="line"><span class="cl"><span class="c1">; 820: L0: 488BE3 MOV RSP, RBX</span> </span></span><span class="line"><span class="cl"><span class="c1">; 823: E818A237FF CALL #x21B00A40 ; GENERIC-+</span> </span></span><span class="line"><span class="cl"><span class="c1">; 828: 488BE5 MOV RSP, RBP</span> </span></span><span class="line"><span class="cl"><span class="c1">; 82B: F8 CLC</span> </span></span><span class="line"><span class="cl"><span class="c1">; 82C: 5D POP RBP</span> </span></span><span class="line"><span class="cl"><span class="c1">; 82D: C3 RET</span> </span></span><span class="line"><span class="cl"><span class="c1">; 82E: CC0F BREAK 15 ; Invalid argument count trap</span> </span></span></code></pre></div><p>===</p> <h1 id="まとめ">まとめ</h1> <hr> <ul> <li>多値とタプルは違うよ</li> <li>Common Lispの多値はダイナミックだよ</li> <li>Common Lispはダイナミックだよ</li> <li>スタックマシンの多値は特別扱いされてるよ</li> <li>レジスタマシンの多値はハックが詰まってるよ</li> <li><a href="https://gitlab.com/snippets/1779413">コード</a></li> </ul>