LoginSignup
6
5

Delete article

Deleted articles cannot be recovered.

Draft of this article would be also deleted.

Are you sure you want to delete this article?

More than 5 years have passed since last update.

@ProjectICKX(ICKX Project)inProject ICKX

mb_strwidthの返す値が怪しかったので調べてみた

Last updated at Posted at 2015-10-30

JavaScriptにmb_strimwidthを移植していた時に文字幅が合わなくなったので調べてみた。

※取り急ぎ関数の返り値から実体をマップしただけで、PHPの生コードは洗っていないためご注意ください。

結論

数万字単位で仕様と異なる文字幅が返ってくる。

見た感じ明らかにfull widthな文字が1文字分の幅扱いだったり、mb_strwidthによる文字幅判定は結構危ないかも・・・

U+0000 - U+10FFFFの範囲内で"mb_strwidthとして"正しい仕様

character width
U+0000 - U+10FF 1
U+1100 - U+115F 2
U+1160 - U+11A2 1
U+11A3 - U+11A7 2
U+11A8 - U+11F9 1
U+11FA - U+11FF 2
U+1200 - U+2328 1
U+2329 - U+232A 2
U+232B - U+2E7F 1
U+2E80 - U+2E99 2
U+2E9A - U+2E9A 1
U+2E9B - U+2EF3 2
U+2EF4 - U+2EFF 1
U+2F00 - U+2FD5 2
U+2FD6 - U+2FEF 1
U+2FF0 - U+2FFB 2
U+2FFC - U+2FFF 1
U+3000 - U+303E 2
U+303F - U+3040 1
U+3041 - U+3096 2
U+3097 - U+3098 1
U+3099 - U+30FF 2
U+3100 - U+3104 1
U+3105 - U+312D 2
U+312E - U+3130 1
U+3131 - U+318E 2
U+318F - U+318F 1
U+3190 - U+31BA 2
U+31BB - U+31BF 1
U+31C0 - U+31E3 2
U+31E4 - U+31EF 1
U+31F0 - U+321E 2
U+321F - U+321F 1
U+3220 - U+3247 2
U+3248 - U+324F 1
U+3250 - U+32FE 2
U+32FF - U+32FF 1
U+3300 - U+4DBF 2
U+4DC0 - U+4DFF 1
U+4E00 - U+A48C 2
U+A48D - U+A48F 1
U+A490 - U+A4C6 2
U+A4C7 - U+A95F 1
U+A960 - U+A97C 2
U+A97D - U+ABFF 1
U+AC00 - U+D7A3 2
U+D7A4 - U+D7AF 1
U+D7B0 - U+D7C6 2
U+D7C7 - U+D7CA 1
U+D7CB - U+D7FB 2
U+D7FC - U+F8FF 1
U+F900 - U+FAFF 2
U+FB00 - U+FE0F 1
U+FE10 - U+FE19 2
U+FE1A - U+FE2F 1
U+FE30 - U+FE52 2
U+FE53 - U+FE53 1
U+FE54 - U+FE66 2
U+FE67 - U+FE67 1
U+FE68 - U+FE6B 2
U+FE6C - U+FF00 1
U+FF01 - U+FF60 2
U+FF61 - U+FFDF 1
U+FFE0 - U+FFE6 2
U+FFE7 - U+1AFFF 1
U+1B000 - U+1B001 2
U+1B002 - U+1F1FF 1
U+1F200 - U+1F202 2
U+1F203 - U+1F20F 1
U+1F210 - U+1F23A 2
U+1F23B - U+1F23F 1
U+1F240 - U+1F248 2
U+1F249 - U+1F24F 1
U+1F250 - U+1F251 2
U+1F252 - U+1FFFF 1
U+20000 - U+2FFFD 2
U+2FFFE - U+2FFFF 1
U+30000 - U+3FFFD 2
U+3FFFE - U+10FFFF 1

検証バージョン

PHP 5.6.15

PHP Manualにある仕様

PHP: mb_strwidth - Manual
http://php.net/manual/ja/function.mb-strwidth.php

character width
U+0000 - U+0019 0
U+0020 - U+1FFF 1
U+2000 - U+FF60 2
U+FF61 - U+FF9F 1
U+FFA0 - 2

発端

**※**の幅に差分がある

PHPの場合
mb_strwidth('※', 'UTF-8') === 2; // is false
mb_strwidth('※', 'UTF-8') === 1; // is true
JSの場合
var char_code = '※'.charCodeAt(0);
var width = 0;
if (0x0000 <= char_code && char_code <= 0x0019) {
} else if (0x0020 <= char_code && char_code <= 0x1FFF) {
    width = 1;
} else if (0x2000 <= char_code && char_code <= 0xFF60) {
    width = 2;
} else if (0xFF61 <= char_code && char_code <= 0xFF9F) {
    width = 1;
} else if (0xFFA0 <= char_code) {
    width = 2;
}
width == 2; // is true

PHP Manualにある仕様に則って作ったのに差分があるじゃないか！
※ '※'は0x203Bのため、U+2000 - U+FF60の範囲に入ります。

実際の値の洗い出し

次のコードで実際の文字幅を洗い出し。

<html>
<head></head>
<body>

<table border="1">
    <tbody>
        <tr>
            <td>start char</td>
            <td>code (dex)</td>
            <td>range</td>
            <td>mb_strwidth</td>
            <td>array</td>
        </tr>
<?php
function int2utf8($code_point) {
	//UTF-16コードポイント内判定
	if ($code_point < 0) {
		throw new \Exception(sprintf('%1$s is out of range UTF-16 code point (0x000000 - 0x10FFFF)', $code_point));
	}
	if (0x10FFFF < $code_point) {
		throw new \Exception(sprintf('0x%1$X is out of range UTF-16 code point (0x000000 - 0x10FFFF)', $code_point));
	}

	//サロゲートペア判定
	if (0xD800 <= $code_point && $code_point <= 0xDFFF) {
		throw new \Exception(sprintf('0x%X is in of range surrogate pair code point (0xD800 - 0xDFFF)', $code_point));
	}

	//1番目のバイトのみでchr関数が使えるケース
	if ($code_point < 0x80) {
		return chr($code_point);
	}

	//2番目のバイトを考慮する必要があるケース
	if ($code_point < 0xA0) {
		return chr(0xC0 | $code_point >> 6) . chr(0x80 | $code_point & 0x3F);
	}

	//数値実体参照表記からの変換
	return html_entity_decode('&#'. $code_point .';');
}

$stacker            = [];
$prev_width         = -1;
$prev_dec_char_code = 0;
$start                       = hexdec('0x0');
$end                         = hexdec('0x10FFFF');

for ($i = $start;$i <= $end;$i++) {
    if (0xD800 <= $i && $i <= 0xDFFF) {
        continue;
    }
    $char = int2utf8($i);

    $current_width = mb_strwidth($char, 'UTF-8');
    if ($prev_width !== $current_width) {
        $stacker[] = [
            'char'                  => $char,
            'dec_char_code'         => $i,
            'width'                 => $current_width,
        ];

        $prev_dec_char_code = $i;
        $prev_width         = $current_width;
    }
}

$i = 1;
foreach ($stacker as $stack) {
    $next = isset($stacker[$i]) ? $stacker[$i] : ['dec_char_code' => $end + 1];
    $i++;
?>
        <tr>
            <td><?= $stack['char'] ?></td>
            <td><?= sprintf('0x%X', $stack['dec_char_code']) ?> (<?= $stack['dec_char_code'] ?>)</td>
            <td><?= sprintf("U+%X - U+%X", $stack['dec_char_code'], $next['dec_char_code'] - 1); ?></td>
            <td><?= $stack['width'] ?></td>
            <td><?= sprintf("[hexdec('0x%X'), hexdec('0x%X'), %s],", $stack['dec_char_code'], $next['dec_char_code'] - 1, $stack['width']); ?></td>
        </tr>
<?php
}
?>
    </tbody>
</table>

</body>
</html>

検証

次のコードで洗い出した値と実際の値に差分が無いか確認。
diff countが0なら問題無し。

<html>
<head></head>
<body>
<?php

function int2utf8($code_point) {
	//UTF-16コードポイント内判定
	if ($code_point < 0) {
		throw new \Exception(sprintf('%1$s is out of range UTF-16 code point (0x000000 - 0x10FFFF)', $code_point));
	}
	if (0x10FFFF < $code_point) {
		throw new \Exception(sprintf('0x%1$X is out of range UTF-16 code point (0x000000 - 0x10FFFF)', $code_point));
	}

	//サロゲートペア判定
	if (0xD800 <= $code_point && $code_point <= 0xDFFF) {
		throw new \Exception(sprintf('0x%X is in of range surrogate pair code point (0xD800 - 0xDFFF)', $code_point));
	}

	//1番目のバイトのみでchr関数が使えるケース
	if ($code_point < 0x80) {
		return chr($code_point);
	}

	//2番目のバイトを考慮する必要があるケース
	if ($code_point < 0xA0) {
		return chr(0xC0 | $code_point >> 6) . chr(0x80 | $code_point & 0x3F);
	}

	//数値実体参照表記からの変換
	return html_entity_decode('&#'. $code_point .';');
}

$spec_list = [
	[hexdec('0x0'), hexdec('0x10FF'), 1],
	[hexdec('0x1100'), hexdec('0x115F'), 2],
	[hexdec('0x1160'), hexdec('0x11A2'), 1],
	[hexdec('0x11A3'), hexdec('0x11A7'), 2],
	[hexdec('0x11A8'), hexdec('0x11F9'), 1],
	[hexdec('0x11FA'), hexdec('0x11FF'), 2],
	[hexdec('0x1200'), hexdec('0x2328'), 1],
	[hexdec('0x2329'), hexdec('0x232A'), 2],
	[hexdec('0x232B'), hexdec('0x2E7F'), 1],
	[hexdec('0x2E80'), hexdec('0x2E99'), 2],
	[hexdec('0x2E9A'), hexdec('0x2E9A'), 1],
	[hexdec('0x2E9B'), hexdec('0x2EF3'), 2],
	[hexdec('0x2EF4'), hexdec('0x2EFF'), 1],
	[hexdec('0x2F00'), hexdec('0x2FD5'), 2],
	[hexdec('0x2FD6'), hexdec('0x2FEF'), 1],
	[hexdec('0x2FF0'), hexdec('0x2FFB'), 2],
	[hexdec('0x2FFC'), hexdec('0x2FFF'), 1],
	[hexdec('0x3000'), hexdec('0x303E'), 2],
	[hexdec('0x303F'), hexdec('0x3040'), 1],
	[hexdec('0x3041'), hexdec('0x3096'), 2],
	[hexdec('0x3097'), hexdec('0x3098'), 1],
	[hexdec('0x3099'), hexdec('0x30FF'), 2],
	[hexdec('0x3100'), hexdec('0x3104'), 1],
	[hexdec('0x3105'), hexdec('0x312D'), 2],
	[hexdec('0x312E'), hexdec('0x3130'), 1],
	[hexdec('0x3131'), hexdec('0x318E'), 2],
	[hexdec('0x318F'), hexdec('0x318F'), 1],
	[hexdec('0x3190'), hexdec('0x31BA'), 2],
	[hexdec('0x31BB'), hexdec('0x31BF'), 1],
	[hexdec('0x31C0'), hexdec('0x31E3'), 2],
	[hexdec('0x31E4'), hexdec('0x31EF'), 1],
	[hexdec('0x31F0'), hexdec('0x321E'), 2],
	[hexdec('0x321F'), hexdec('0x321F'), 1],
	[hexdec('0x3220'), hexdec('0x3247'), 2],
	[hexdec('0x3248'), hexdec('0x324F'), 1],
	[hexdec('0x3250'), hexdec('0x32FE'), 2],
	[hexdec('0x32FF'), hexdec('0x32FF'), 1],
	[hexdec('0x3300'), hexdec('0x4DBF'), 2],
	[hexdec('0x4DC0'), hexdec('0x4DFF'), 1],
	[hexdec('0x4E00'), hexdec('0xA48C'), 2],
	[hexdec('0xA48D'), hexdec('0xA48F'), 1],
	[hexdec('0xA490'), hexdec('0xA4C6'), 2],
	[hexdec('0xA4C7'), hexdec('0xA95F'), 1],
	[hexdec('0xA960'), hexdec('0xA97C'), 2],
	[hexdec('0xA97D'), hexdec('0xABFF'), 1],
	[hexdec('0xAC00'), hexdec('0xD7A3'), 2],
	[hexdec('0xD7A4'), hexdec('0xD7AF'), 1],
	[hexdec('0xD7B0'), hexdec('0xD7C6'), 2],
	[hexdec('0xD7C7'), hexdec('0xD7CA'), 1],
	[hexdec('0xD7CB'), hexdec('0xD7FB'), 2],
	[hexdec('0xD7FC'), hexdec('0xF8FF'), 1],
	[hexdec('0xF900'), hexdec('0xFAFF'), 2],
	[hexdec('0xFB00'), hexdec('0xFE0F'), 1],
	[hexdec('0xFE10'), hexdec('0xFE19'), 2],
	[hexdec('0xFE1A'), hexdec('0xFE2F'), 1],
	[hexdec('0xFE30'), hexdec('0xFE52'), 2],
	[hexdec('0xFE53'), hexdec('0xFE53'), 1],
	[hexdec('0xFE54'), hexdec('0xFE66'), 2],
	[hexdec('0xFE67'), hexdec('0xFE67'), 1],
	[hexdec('0xFE68'), hexdec('0xFE6B'), 2],
	[hexdec('0xFE6C'), hexdec('0xFF00'), 1],
	[hexdec('0xFF01'), hexdec('0xFF60'), 2],
	[hexdec('0xFF61'), hexdec('0xFFDF'), 1],
	[hexdec('0xFFE0'), hexdec('0xFFE6'), 2],
	[hexdec('0xFFE7'), hexdec('0x1AFFF'), 1],
	[hexdec('0x1B000'), hexdec('0x1B001'), 2],
	[hexdec('0x1B002'), hexdec('0x1F1FF'), 1],
	[hexdec('0x1F200'), hexdec('0x1F202'), 2],
	[hexdec('0x1F203'), hexdec('0x1F20F'), 1],
	[hexdec('0x1F210'), hexdec('0x1F23A'), 2],
	[hexdec('0x1F23B'), hexdec('0x1F23F'), 1],
	[hexdec('0x1F240'), hexdec('0x1F248'), 2],
	[hexdec('0x1F249'), hexdec('0x1F24F'), 1],
	[hexdec('0x1F250'), hexdec('0x1F251'), 2],
	[hexdec('0x1F252'), hexdec('0x1FFFF'), 1],
	[hexdec('0x20000'), hexdec('0x2FFFD'), 2],
	[hexdec('0x2FFFE'), hexdec('0x2FFFF'), 1],
	[hexdec('0x30000'), hexdec('0x3FFFD'), 2],
	[hexdec('0x3FFFE'), hexdec('0x10FFFF'), 1],
];

$spec = array_shift($spec_list);

$diff_cnt = 0;

?>
<table border="2">
	<tr>
		<td>char</td>
		<td>code (dex)</td>
		<td>spec width</td>
		<td>mb_strwidth</td>
	</tr>
<?php
for ($i = hexdec('0x0000'), $end = hexdec('0x10FFFF');$i <= $end;$i++) {
    if (0xD800 <= $i && $i <= 0xDFFF) {
        continue;
    }
    $target_text = int2utf8($i);

	if ($spec[1] < $i) {
		$spec = array_shift($spec_list);
	}

	if (mb_strwidth($target_text) !== $spec[2]) {
		$diff_cnt++;
?>
	<tr>
		<td><?= $target_text ?></td>
		<td><?= sprintf('0x%X', $i) ?> (<?= $i ?>)</td>
		<td><?= $spec[2] ?></td>
		<td><?= mb_strwidth($target_text) ?></td>
	</tr>
<?php
	}
}
?>
</table>

diff count : <?= $diff_cnt; ?>

</body>
</html>
6
5
6

Register as a new user and use Qiita more conveniently

  1. You get articles that match your needs
  2. You can efficiently read back useful information
  3. You can use dark theme
What you can do with signing up
Sign upLogin
6
5

Delete article

Deleted articles cannot be recovered.

Draft of this article would be also deleted.

Are you sure you want to delete this article?