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| author | nsfisis <nsfisis@gmail.com> | 2025-03-29 00:47:55 +0900 |
|---|---|---|
| committer | nsfisis <nsfisis@gmail.com> | 2025-03-29 00:55:14 +0900 |
| commit | d30dfc89bf1b673b2fdc0638766b930adaec228c (patch) | |
| tree | 739d8826451947adfeb526ef1adeb1db397a9af4 /vhosts/blog/public/posts/2023-01-10/phperkaigi-2023-unused-token-quiz-3 | |
| parent | f65ec15aaf8fc46685c39d721cab82f64baead8c (diff) | |
| download | nsfisis.dev-d30dfc89bf1b673b2fdc0638766b930adaec228c.tar.gz nsfisis.dev-d30dfc89bf1b673b2fdc0638766b930adaec228c.tar.zst nsfisis.dev-d30dfc89bf1b673b2fdc0638766b930adaec228c.zip | |
feat(blog/nuldoc): migrate syntax highlighter from highlight.js to shiki.js
Diffstat (limited to 'vhosts/blog/public/posts/2023-01-10/phperkaigi-2023-unused-token-quiz-3')
| -rw-r--r-- | vhosts/blog/public/posts/2023-01-10/phperkaigi-2023-unused-token-quiz-3/index.html | 341 |
1 files changed, 177 insertions, 164 deletions
diff --git a/vhosts/blog/public/posts/2023-01-10/phperkaigi-2023-unused-token-quiz-3/index.html b/vhosts/blog/public/posts/2023-01-10/phperkaigi-2023-unused-token-quiz-3/index.html index 38e6a3f6..6cad79cb 100644 --- a/vhosts/blog/public/posts/2023-01-10/phperkaigi-2023-unused-token-quiz-3/index.html +++ b/vhosts/blog/public/posts/2023-01-10/phperkaigi-2023-unused-token-quiz-3/index.html @@ -14,8 +14,7 @@ <meta property="og:locale" content="ja_JP"> <link rel="icon" type="image/svg+xml" href="/favicon.svg"> <title>PHPerKaigi 2023: ボツになったトークン問題 その 3｜REPL: Rest-Eat-Program Loop</title> - <link rel="stylesheet" href="/style.css?h=79020a898c7052f79b32e90376a4497d"> - <link rel="stylesheet" href="/hl.css?h=340e65ffd5c17713efc9107c06304f7b"> + <link rel="stylesheet" href="/style.css?h=60eb349e583f5bd51518a7eb98598043"> </head> <body class="single"> <header class="header"> @@ -96,118 +95,120 @@ 注意: これはボツ問なので、得られたトークンを PHPerKaigi で入力してもポイントにはならない。 </p> - <pre class="highlight" language="php"><code class="highlight"><span class="hljs-meta"><?php</span> -<span class="hljs-keyword">try</span> { - <span class="hljs-title function_ invoke__">f</span>(<span class="hljs-title function_ invoke__">g</span>() / <span class="hljs-keyword">__LINE__</span>); -} <span class="hljs-keyword">catch</span> (<span class="hljs-built_in">Throwable</span> <span class="hljs-variable">$e</span>) { - <span class="hljs-keyword">while</span> (<span class="hljs-variable">$e</span> = <span class="hljs-variable">$e</span>-><span class="hljs-title function_ invoke__">getPrevious</span>()) <span class="hljs-title function_ invoke__">printf</span>(<span class="hljs-string">'%c'</span>, <span class="hljs-variable">$e</span>-><span class="hljs-title function_ invoke__">getLine</span>() + <span class="hljs-number">23</span>); - <span class="hljs-keyword">echo</span> <span class="hljs-string">"\n"</span>; -} -<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">f</span>(<span class="hljs-params"><span class="hljs-keyword">int</span> <span class="hljs-variable">$i</span></span>) </span>{ - <span class="hljs-keyword">if</span> (<span class="hljs-variable">$i</span> < <span class="hljs-number">0</span>) <span class="hljs-title function_ invoke__">f</span>(); - <span class="hljs-keyword">try</span> { - <span class="hljs-keyword">match</span> (<span class="hljs-variable">$i</span>) { - <span class="hljs-number">0</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - - - <span class="hljs-number">15</span>, <span class="hljs-number">36</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - <span class="hljs-number">14</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - <span class="hljs-number">37</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - - - - - - - - - - <span class="hljs-number">6</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - <span class="hljs-number">5</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - <span class="hljs-number">22</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - - - - <span class="hljs-number">34</span>, <span class="hljs-number">35</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - - - - - - - - <span class="hljs-number">25</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - <span class="hljs-number">17</span>, <span class="hljs-number">21</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - <span class="hljs-number">24</span>, <span class="hljs-number">32</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - - - - - - - <span class="hljs-number">33</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - <span class="hljs-number">16</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - - <span class="hljs-number">18</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - - - - - - - - <span class="hljs-number">7</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - <span class="hljs-number">2</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - <span class="hljs-number">1</span>, <span class="hljs-number">20</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - <span class="hljs-number">10</span>, <span class="hljs-number">28</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - <span class="hljs-number">8</span>, <span class="hljs-number">12</span>, <span class="hljs-number">26</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - <span class="hljs-number">4</span>, <span class="hljs-number">9</span>, <span class="hljs-number">13</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - - - - - <span class="hljs-number">31</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - <span class="hljs-number">29</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - <span class="hljs-number">11</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - - - <span class="hljs-number">3</span>, <span class="hljs-number">19</span>, <span class="hljs-number">23</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - - <span class="hljs-number">27</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - <span class="hljs-number">30</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - }; - } <span class="hljs-keyword">finally</span> { - <span class="hljs-title function_ invoke__">f</span>(<span class="hljs-variable">$i</span> - <span class="hljs-number">1</span>); - } -} - - - - - - - -<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">g</span>(<span class="hljs-params"></span>) </span>{ - <span class="hljs-keyword">return</span> <span class="hljs-keyword">__LINE__</span>; -}</code></pre> + <div class="codeblock" language="php"> + <pre class="shiki github-light" style="background-color:#f5f5f5;color:#24292e" tabindex="0"><code><span class="line"><span style="color:#D73A49"><?</span><span style="color:#005CC5">php</span></span> +<span class="line"><span style="color:#D73A49">try</span><span style="color:#24292E"> {</span></span> +<span class="line"><span style="color:#6F42C1"> f</span><span style="color:#24292E">(</span><span style="color:#6F42C1">g</span><span style="color:#24292E">() </span><span style="color:#D73A49">/</span><span style="color:#005CC5"> __LINE__</span><span style="color:#24292E">);</span></span> +<span class="line"><span style="color:#24292E">} </span><span style="color:#D73A49">catch</span><span style="color:#24292E"> (</span><span style="color:#005CC5">Throwable</span><span style="color:#24292E"> $e) {</span></span> +<span class="line"><span style="color:#D73A49"> while</span><span style="color:#24292E"> ($e </span><span style="color:#D73A49">=</span><span style="color:#24292E"> $e</span><span style="color:#D73A49">-></span><span style="color:#6F42C1">getPrevious</span><span style="color:#24292E">()) </span><span style="color:#005CC5">printf</span><span style="color:#24292E">(</span><span style="color:#032F62">'%c'</span><span style="color:#24292E">, $e</span><span style="color:#D73A49">-></span><span style="color:#6F42C1">getLine</span><span style="color:#24292E">() </span><span style="color:#D73A49">+</span><span style="color:#005CC5"> 23</span><span style="color:#24292E">);</span></span> +<span class="line"><span style="color:#005CC5"> echo</span><span style="color:#032F62"> "</span><span style="color:#005CC5">\n</span><span style="color:#032F62">"</span><span style="color:#24292E">;</span></span> +<span class="line"><span style="color:#24292E">}</span></span> +<span class="line"><span style="color:#D73A49">function</span><span style="color:#6F42C1"> f</span><span style="color:#24292E">(</span><span style="color:#D73A49">int</span><span style="color:#24292E"> $i) {</span></span> +<span class="line"><span style="color:#D73A49"> if</span><span style="color:#24292E"> ($i </span><span style="color:#D73A49"><</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">) </span><span style="color:#6F42C1">f</span><span style="color:#24292E">();</span></span> +<span class="line"><span style="color:#D73A49"> try</span><span style="color:#24292E"> {</span></span> +<span class="line"><span style="color:#D73A49"> match</span><span style="color:#24292E"> ($i) {</span></span> +<span class="line"><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 15</span><span style="color:#24292E">, </span><span style="color:#005CC5">36</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"><span style="color:#005CC5"> 14</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"><span style="color:#005CC5"> 37</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 6</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 5</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 22</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 34</span><span style="color:#24292E">, </span><span style="color:#005CC5">35</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 25</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"><span style="color:#005CC5"> 17</span><span style="color:#24292E">, </span><span style="color:#005CC5">21</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 24</span><span style="color:#24292E">, </span><span style="color:#005CC5">32</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 33</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 16</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 18</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 7</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 2</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"><span style="color:#005CC5"> 1</span><span style="color:#24292E">, </span><span style="color:#005CC5">20</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"><span style="color:#005CC5"> 10</span><span style="color:#24292E">, </span><span style="color:#005CC5">28</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"><span style="color:#005CC5"> 8</span><span style="color:#24292E">, </span><span style="color:#005CC5">12</span><span style="color:#24292E">, </span><span style="color:#005CC5">26</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"><span style="color:#005CC5"> 4</span><span style="color:#24292E">, </span><span style="color:#005CC5">9</span><span style="color:#24292E">, </span><span style="color:#005CC5">13</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 31</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 29</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 11</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 3</span><span style="color:#24292E">, </span><span style="color:#005CC5">19</span><span style="color:#24292E">, </span><span style="color:#005CC5">23</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 27</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 30</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"><span style="color:#24292E"> };</span></span> +<span class="line"><span style="color:#24292E"> } </span><span style="color:#D73A49">finally</span><span style="color:#24292E"> {</span></span> +<span class="line"><span style="color:#6F42C1"> f</span><span style="color:#24292E">($i </span><span style="color:#D73A49">-</span><span style="color:#005CC5"> 1</span><span style="color:#24292E">);</span></span> +<span class="line"><span style="color:#24292E"> }</span></span> +<span class="line"><span style="color:#24292E">}</span></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"><span style="color:#D73A49">function</span><span style="color:#6F42C1"> g</span><span style="color:#24292E">() {</span></span> +<span class="line"><span style="color:#D73A49"> return</span><span style="color:#005CC5"> __LINE__</span><span style="color:#24292E">;</span></span> +<span class="line"><span style="color:#24292E">}</span></span></code></pre> + </div> <p> "Catchline" と名付けた作品。実行するとトークン <code>#base64_decode('SGVsbG8sIFdvcmxkIQ==')</code> が得られる。 @@ -247,20 +248,22 @@ このうち 1つ目のケースは、 <code>finally</code> 節の中でエラーを投げると PHP 処理系が勝手に <code>$previous</code> を設定してくれる。 </p> - <pre class="highlight" language="php"><code class="highlight"><span class="hljs-meta"><?php</span> - -<span class="hljs-keyword">try</span> { - <span class="hljs-keyword">try</span> { - <span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> <span class="hljs-built_in">Exception</span>(<span class="hljs-string">"Error 1"</span>); - } <span class="hljs-keyword">finally</span> { - <span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> <span class="hljs-built_in">Exception</span>(<span class="hljs-string">"Error 2"</span>); - } -} <span class="hljs-keyword">catch</span> (<span class="hljs-built_in">Exception</span> <span class="hljs-variable">$e</span>) { - <span class="hljs-keyword">echo</span> <span class="hljs-variable">$e</span>-><span class="hljs-title function_ invoke__">getMessage</span>() . PHP_EOL; - <span class="hljs-comment">// => Error 2</span> - <span class="hljs-keyword">echo</span> <span class="hljs-variable">$e</span>-><span class="hljs-title function_ invoke__">getPrevious</span>()-><span class="hljs-title function_ invoke__">getMessage</span>() . PHP_EOL; - <span class="hljs-comment">// => Error 1</span> -}</code></pre> + <div class="codeblock" language="php"> + <pre class="shiki github-light" style="background-color:#f5f5f5;color:#24292e" tabindex="0"><code><span class="line"><span style="color:#D73A49"><?</span><span style="color:#005CC5">php</span></span> +<span class="line"></span> +<span class="line"><span style="color:#D73A49">try</span><span style="color:#24292E"> {</span></span> +<span class="line"><span style="color:#D73A49"> try</span><span style="color:#24292E"> {</span></span> +<span class="line"><span style="color:#D73A49"> throw</span><span style="color:#D73A49"> new</span><span style="color:#005CC5"> Exception</span><span style="color:#24292E">(</span><span style="color:#032F62">"Error 1"</span><span style="color:#24292E">);</span></span> +<span class="line"><span style="color:#24292E"> } </span><span style="color:#D73A49">finally</span><span style="color:#24292E"> {</span></span> +<span class="line"><span style="color:#D73A49"> throw</span><span style="color:#D73A49"> new</span><span style="color:#005CC5"> Exception</span><span style="color:#24292E">(</span><span style="color:#032F62">"Error 2"</span><span style="color:#24292E">);</span></span> +<span class="line"><span style="color:#24292E"> }</span></span> +<span class="line"><span style="color:#24292E">} </span><span style="color:#D73A49">catch</span><span style="color:#24292E"> (</span><span style="color:#005CC5">Exception</span><span style="color:#24292E"> $e) {</span></span> +<span class="line"><span style="color:#005CC5"> echo</span><span style="color:#24292E"> $e</span><span style="color:#D73A49">-></span><span style="color:#6F42C1">getMessage</span><span style="color:#24292E">() </span><span style="color:#D73A49">.</span><span style="color:#005CC5"> PHP_EOL</span><span style="color:#24292E">;</span></span> +<span class="line"><span style="color:#6A737D"> // => Error 2</span></span> +<span class="line"><span style="color:#005CC5"> echo</span><span style="color:#24292E"> $e</span><span style="color:#D73A49">-></span><span style="color:#6F42C1">getPrevious</span><span style="color:#24292E">()</span><span style="color:#D73A49">-></span><span style="color:#6F42C1">getMessage</span><span style="color:#24292E">() </span><span style="color:#D73A49">.</span><span style="color:#005CC5"> PHP_EOL</span><span style="color:#24292E">;</span></span> +<span class="line"><span style="color:#6A737D"> // => Error 1</span></span> +<span class="line"><span style="color:#24292E">}</span></span></code></pre> + </div> <p> この知識を元に、トークンの出力部を解析してみる。 @@ -273,15 +276,17 @@ 出力部をコメントや改行を追加して再掲する: </p> - <pre class="highlight" language="php"><code class="highlight"><span class="hljs-meta"><?php</span> -<span class="hljs-keyword">try</span> { - <span class="hljs-title function_ invoke__">f</span>(<span class="hljs-title function_ invoke__">g</span>() / <span class="hljs-keyword">__LINE__</span>); -} <span class="hljs-keyword">catch</span> (<span class="hljs-built_in">Throwable</span> <span class="hljs-variable">$e</span>) { - <span class="hljs-keyword">while</span> (<span class="hljs-variable">$e</span> = <span class="hljs-variable">$e</span>-><span class="hljs-title function_ invoke__">getPrevious</span>()) { - <span class="hljs-title function_ invoke__">printf</span>(<span class="hljs-string">'%c'</span>, <span class="hljs-variable">$e</span>-><span class="hljs-title function_ invoke__">getLine</span>() + <span class="hljs-number">23</span>); - } - <span class="hljs-keyword">echo</span> <span class="hljs-string">"\n"</span>; -}</code></pre> + <div class="codeblock" language="php"> + <pre class="shiki github-light" style="background-color:#f5f5f5;color:#24292e" tabindex="0"><code><span class="line"><span style="color:#D73A49"><?</span><span style="color:#005CC5">php</span></span> +<span class="line"><span style="color:#D73A49">try</span><span style="color:#24292E"> {</span></span> +<span class="line"><span style="color:#6F42C1"> f</span><span style="color:#24292E">(</span><span style="color:#6F42C1">g</span><span style="color:#24292E">() </span><span style="color:#D73A49">/</span><span style="color:#005CC5"> __LINE__</span><span style="color:#24292E">);</span></span> +<span class="line"><span style="color:#24292E">} </span><span style="color:#D73A49">catch</span><span style="color:#24292E"> (</span><span style="color:#005CC5">Throwable</span><span style="color:#24292E"> $e) {</span></span> +<span class="line"><span style="color:#D73A49"> while</span><span style="color:#24292E"> ($e </span><span style="color:#D73A49">=</span><span style="color:#24292E"> $e</span><span style="color:#D73A49">-></span><span style="color:#6F42C1">getPrevious</span><span style="color:#24292E">()) {</span></span> +<span class="line"><span style="color:#005CC5"> printf</span><span style="color:#24292E">(</span><span style="color:#032F62">'%c'</span><span style="color:#24292E">, $e</span><span style="color:#D73A49">-></span><span style="color:#6F42C1">getLine</span><span style="color:#24292E">() </span><span style="color:#D73A49">+</span><span style="color:#005CC5"> 23</span><span style="color:#24292E">);</span></span> +<span class="line"><span style="color:#24292E"> }</span></span> +<span class="line"><span style="color:#005CC5"> echo</span><span style="color:#032F62"> "</span><span style="color:#005CC5">\n</span><span style="color:#032F62">"</span><span style="color:#24292E">;</span></span> +<span class="line"><span style="color:#24292E">}</span></span></code></pre> + </div> <p> 出力をおこなう <code>catch</code> 節を見てみると、 <code>Throwable::getPrevious()</code> を呼び出してエラーチェインを辿り、 <code>Throwable::getLine()</code> でエラーが発生した行数を取得している。その行数に <code>23</code> なるマジックナンバーを足し、フォーマット指定子 <code>%c</code> で出力している。 @@ -291,7 +296,9 @@ フォーマット指定子 <code>%c</code> は、整数を ASCII コード<span></span> と見做して印字する。トークン <code>#base64_decode('SGVsbG8sIFdvcmxkIQ==')</code> の <code>b</code> であれば、ASCII コード <code>98</code> なので、75 行目で発生したエラー、 </p> - <pre class="highlight" language="php"><code class="highlight"><span class="hljs-number">1</span>, <span class="hljs-number">20</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>,</code></pre> + <div class="codeblock" language="php"> + <pre class="shiki github-light" style="background-color:#f5f5f5;color:#24292e" tabindex="0"><code><span class="line"><span style="color:#005CC5">1</span><span style="color:#24292E">, </span><span style="color:#005CC5">20</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span></code></pre> + </div> <p> によって表現されている。エラーを起こす方法はいろいろと考えられるが、今回はゼロ除算を使った。 @@ -308,38 +315,44 @@ <code>f()</code> の定義を再掲する (エラーオブジェクトの行数を利用しているので、一部分だけ抜き出すと値が変わることに注意): </p> - <pre class="highlight" language="php"><code class="highlight"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">f</span>(<span class="hljs-params"><span class="hljs-keyword">int</span> <span class="hljs-variable">$i</span></span>) </span>{ - <span class="hljs-keyword">if</span> (<span class="hljs-variable">$i</span> < <span class="hljs-number">0</span>) <span class="hljs-title function_ invoke__">f</span>(); - <span class="hljs-keyword">try</span> { - <span class="hljs-keyword">match</span> (<span class="hljs-variable">$i</span>) { - <span class="hljs-number">0</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, <span class="hljs-comment">// 12 行目</span> - - - - <span class="hljs-number">15</span>, <span class="hljs-number">36</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - <span class="hljs-number">14</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - <span class="hljs-number">37</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, - - <span class="hljs-comment">// (略)</span> - - <span class="hljs-number">30</span> => <span class="hljs-number">0</span> / <span class="hljs-number">0</span>, <span class="hljs-comment">// 97 行目</span> - }; - } <span class="hljs-keyword">finally</span> { - <span class="hljs-title function_ invoke__">f</span>(<span class="hljs-variable">$i</span> - <span class="hljs-number">1</span>); - } -}</code></pre> + <div class="codeblock" language="php"> + <pre class="shiki github-light" style="background-color:#f5f5f5;color:#24292e" tabindex="0"><code><span class="line"><span style="color:#D73A49">function</span><span style="color:#6F42C1"> f</span><span style="color:#24292E">(</span><span style="color:#D73A49">int</span><span style="color:#24292E"> $i) {</span></span> +<span class="line"><span style="color:#D73A49"> if</span><span style="color:#24292E"> ($i </span><span style="color:#D73A49"><</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">) </span><span style="color:#6F42C1">f</span><span style="color:#24292E">();</span></span> +<span class="line"><span style="color:#D73A49"> try</span><span style="color:#24292E"> {</span></span> +<span class="line"><span style="color:#D73A49"> match</span><span style="color:#24292E"> ($i) {</span></span> +<span class="line"><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">, </span><span style="color:#6A737D">// 12 行目</span></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 15</span><span style="color:#24292E">, </span><span style="color:#005CC5">36</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"><span style="color:#005CC5"> 14</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"><span style="color:#005CC5"> 37</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">,</span></span> +<span class="line"></span> +<span class="line"><span style="color:#6A737D"> // (略)</span></span> +<span class="line"></span> +<span class="line"><span style="color:#005CC5"> 30</span><span style="color:#D73A49"> =></span><span style="color:#005CC5"> 0</span><span style="color:#D73A49"> /</span><span style="color:#005CC5"> 0</span><span style="color:#24292E">, </span><span style="color:#6A737D">// 97 行目</span></span> +<span class="line"><span style="color:#24292E"> };</span></span> +<span class="line"><span style="color:#24292E"> } </span><span style="color:#D73A49">finally</span><span style="color:#24292E"> {</span></span> +<span class="line"><span style="color:#6F42C1"> f</span><span style="color:#24292E">($i </span><span style="color:#D73A49">-</span><span style="color:#005CC5"> 1</span><span style="color:#24292E">);</span></span> +<span class="line"><span style="color:#24292E"> }</span></span> +<span class="line"><span style="color:#24292E">}</span></span></code></pre> + </div> <p> 前述のように、 <code>finally</code> 節でエラーを投げると PHP 処理系が <code>$previous</code> を設定する。ここでは、エラーを繋げるために <code>f()</code> を再帰呼び出ししている。最初に <code>f()</code> を呼び出している箇所を確認すると、 </p> - <pre class="highlight" language="php"><code class="highlight"><span class="hljs-meta"><?php</span> -<span class="hljs-keyword">try</span> { - <span class="hljs-title function_ invoke__">f</span>(<span class="hljs-title function_ invoke__">g</span>() / <span class="hljs-keyword">__LINE__</span>); <span class="hljs-comment">// 3 行目</span></code></pre> + <div class="codeblock" language="php"> + <pre class="shiki github-light" style="background-color:#f5f5f5;color:#24292e" tabindex="0"><code><span class="line"><span style="color:#D73A49"><?</span><span style="color:#005CC5">php</span></span> +<span class="line"><span style="color:#D73A49">try</span><span style="color:#24292E"> {</span></span> +<span class="line"><span style="color:#6F42C1"> f</span><span style="color:#24292E">(</span><span style="color:#6F42C1">g</span><span style="color:#24292E">() </span><span style="color:#D73A49">/</span><span style="color:#005CC5"> __LINE__</span><span style="color:#24292E">); </span><span style="color:#6A737D">// 3 行目</span></span></code></pre> + </div> - <pre class="highlight" language="php"><code class="highlight"><span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">g</span>(<span class="hljs-params"></span>) </span>{ - <span class="hljs-keyword">return</span> <span class="hljs-keyword">__LINE__</span>; <span class="hljs-comment">// 111 行目</span> -}</code></pre> + <div class="codeblock" language="php"> + <pre class="shiki github-light" style="background-color:#f5f5f5;color:#24292e" tabindex="0"><code><span class="line"><span style="color:#D73A49">function</span><span style="color:#6F42C1"> g</span><span style="color:#24292E">() {</span></span> +<span class="line"><span style="color:#D73A49"> return</span><span style="color:#005CC5"> __LINE__</span><span style="color:#24292E">; </span><span style="color:#6A737D">// 111 行目</span></span> +<span class="line"><span style="color:#24292E">}</span></span></code></pre> + </div> <p> <code>f()</code> には <code>111 / 3</code> で <code>37</code> が渡されることがわかる。そこから 1 ずつ減らして再帰呼び出ししていき、0 より小さくなったら <code>f()</code> を引数なしで呼び出す。引数の数が足りないと呼び出しに失敗するので、再帰はここで止まる。 |