<!DOCTYPE html>
<html>
<head>
</head>
<body>
<dl style="line-height: 1.5; margin-left: 2em">
<dt style="clear: both; float: left; font-weight: bold; width: 8em">Author</dt>
<dd style="margin-left: 8.5em">Kouhei Sutou <kou****@clear*****></dd>
<dt style="clear: both; float: left; font-weight: bold; width: 8em">Date</dt>
<dd style="margin-left: 8.5em">2012-03-15 18:11:04 +0900 (Thu, 15 Mar 2012)</dd>
<dt style="clear: both; float: left; font-weight: bold; width: 8em">New Revision</dt>
<dd style="margin-left: 8.5em"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058">3d65ee6975a21b499da99b53f362df76f15fc058</a></dd>
<dt style="clear: both; float: left; font-weight: bold; width: 8em">Log</dt>
<dd style="margin-left: 8.5em"><pre style="border: 1px solid #aaa; font-family: Consolas, Menlo, "Liberation Mono", Courier, monospace; line-height: 1.2; padding: 0.5em">doc coding-style: add about NULL in condition</pre></dd>
<dt style="clear: both; float: left; font-weight: bold; width: 8em">Modified files</dt>
<dd style="margin-left: 8.5em">
<ul>
<li><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#diff-0">doc/source/developer/coding_style.rst</a></li>
</ul>
</dd>
</dl>
<div class="diff-section" style="clear: both">
<table style="border-collapse: collapse; border: 1px solid #aaa">
<thead>
<tr class="diff-header" style="border: 1px solid #aaa">
<td colspan="3">
<pre style="border: 0; font-family: Consolas, Menlo, "Liberation Mono", Courier, monospace; line-height: 1.2; margin: 0; padding: 0.5em; white-space: normal"><span class="diff-header" style="background-color: #eaf2f5; color: #999999; display: block; white-space: pre"> Modified: doc/source/developer/coding_style.rst (+15 -0)</span>
<span class="diff-header-mark" style="background-color: #eaf2f5; color: #999999; display: block; white-space: pre">===================================================================</span>
</pre>
</td>
</tr>
</thead>
<tbody>
<tr>
<th class="diff-line-number" style="border: 1px solid #aaa">
<pre style="border: 0; font-family: Consolas, Menlo, "Liberation Mono", Courier, monospace; line-height: 1.2; margin: 0; padding: 0.5em; white-space: normal"><span class="diff-line-number-hunk-header" style="display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0L451">...</a></span>
<span class="diff-line-number-not-changed" style="display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0L452">452</a></span>
<span class="diff-line-number-not-changed" style="display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0L453">453</a></span>
<span class="diff-line-number-not-changed" style="display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0L454">454</a></span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
<span class="diff-line-number-nothing" style="display: block; white-space: pre"> </span>
</pre>
</th>
<th class="diff-line-number" style="border: 1px solid #aaa">
<pre style="border: 0; font-family: Consolas, Menlo, "Liberation Mono", Courier, monospace; line-height: 1.2; margin: 0; padding: 0.5em; white-space: normal"><span class="diff-line-number-hunk-header" style="display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R451">...</a></span>
<span class="diff-line-number-not-changed" style="display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R452">452</a></span>
<span class="diff-line-number-not-changed" style="display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R453">453</a></span>
<span class="diff-line-number-not-changed" style="display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R454">454</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R455">455</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R456">456</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R457">457</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R458">458</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R459">459</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R460">460</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R461">461</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R462">462</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R463">463</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R464">464</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R465">465</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R466">466</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R467">467</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R468">468</a></span>
<span class="diff-line-number-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre"><a href="https://github.com/mroonga/mroonga/commit/3d65ee6975a21b499da99b53f362df76f15fc058#L0R469">469</a></span>
</pre>
</th>
<td class="diff-content" style="border: 1px solid #aaa">
<pre style="border: 0; font-family: Consolas, Menlo, "Liberation Mono", Courier, monospace; line-height: 1.2; margin: 0; padding: 0.5em; white-space: normal"><span class="diff-hunk-header" style="background-color: #eaf2f5; color: #999999; display: block; white-space: pre">@@ -452,3 +452,18 @@ <span class="diff-context" style="background-color: #ffffaa; color: #000000">bool型を用いる</span></span>
<span class="diff-not-changed" style="display: block; white-space: pre"> boolean is_searching = true;</span>
<span class="diff-not-changed" style="display: block; white-space: pre"> if (is_searching == false) { ... }</span>
<span class="diff-not-changed" style="display: block; white-space: pre"> </span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+``NULL`` と比較しない</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+^^^^^^^^^^^^^^^^^^^^^^</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+``NULL`` かどうかを条件式に使う場合は ``value == NULL`` ではなく ``!value`` というように書く。多くの言語で ``NULL`` に相当する値（たとえばLispの ``nil`` ）は偽を表すため、明示的に ``NULL`` と比較しなくても意図は伝わるからである。</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+よい例:</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+ char *name = NULL;</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+ if (!name) { ... }</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+悪い例（ ``NULL`` と比較している）:</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+ char *name = NULL;</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+ if (name == NULL) { ... }</span>
<span class="diff-added" style="background-color: #aaffaa; color: #000000; display: block; white-space: pre">+</span>
</pre>
</td>
</tr>
</tbody>
</table>
</div>
</body>
</html>