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| author | Manuel A. Fernandez Montecelo <manuel.montezelo@gmail.com> | 2016-05-26 16:48:15 +0100 |
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| committer | Manuel A. Fernandez Montecelo <manuel.montezelo@gmail.com> | 2016-05-26 16:48:15 +0100 |
| commit | 5f2b09982312c98863eb9a8dfe2c608b81f58259 (patch) | |
| tree | e5d38581c2f36e1cca02efedd2d85044d77f76f9 /doc/libunistring_10.html | |
| parent | 3e0814cd9862b89c7a39672672937477bd87ddfb (diff) | |
Imported Upstream version 0.9.6upstream/0.9.6
Diffstat (limited to 'doc/libunistring_10.html')
| -rw-r--r-- | doc/libunistring_10.html | 228 |
1 files changed, 148 insertions, 80 deletions
diff --git a/doc/libunistring_10.html b/doc/libunistring_10.html index 617406d6..3f4f5dac 100644 --- a/doc/libunistring_10.html +++ b/doc/libunistring_10.html @@ -1,6 +1,6 @@ <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html401/loose.dtd"> <html> -<!-- Created on March, 30 2010 by texi2html 1.78a --> +<!-- Created on July, 8 2015 by texi2html 1.78a --> <!-- Written by: Lionel Cons <Lionel.Cons@cern.ch> (original author) Karl Berry <karl@freefriends.org> @@ -11,10 +11,10 @@ Send bugs and suggestions to <texi2html-bug@nongnu.org> --> <head> -<title>GNU libunistring: 10. Word breaks in strings <uniwbrk.h></title> +<title>GNU libunistring: 10. Grapheme cluster breaks in strings <unigbrk.h></title> -<meta name="description" content="GNU libunistring: 10. Word breaks in strings <uniwbrk.h>"> -<meta name="keywords" content="GNU libunistring: 10. Word breaks in strings <uniwbrk.h>"> +<meta name="description" content="GNU libunistring: 10. Grapheme cluster breaks in strings <unigbrk.h>"> +<meta name="keywords" content="GNU libunistring: 10. Grapheme cluster breaks in strings <unigbrk.h>"> <meta name="resource-type" content="document"> <meta name="distribution" content="global"> <meta name="Generator" content="texi2html 1.78a"> @@ -42,8 +42,8 @@ ul.toc {list-style: none} <body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> <table cellpadding="1" cellspacing="1" border="0"> -<tr><td valign="middle" align="left">[<a href="libunistring_9.html#SEC37" title="Beginning of this chapter or previous chapter"> << </a>]</td> -<td valign="middle" align="left">[<a href="libunistring_11.html#SEC41" title="Next chapter"> >> </a>]</td> +<tr><td valign="middle" align="left">[<a href="libunistring_9.html#SEC40" title="Beginning of this chapter or previous chapter"> << </a>]</td> +<td valign="middle" align="left">[<a href="libunistring_11.html#SEC44" title="Next chapter"> >> </a>]</td> <td valign="middle" align="left"> </td> <td valign="middle" align="left"> </td> <td valign="middle" align="left"> </td> @@ -51,126 +51,194 @@ ul.toc {list-style: none} <td valign="middle" align="left"> </td> <td valign="middle" align="left">[<a href="libunistring.html#SEC_Top" title="Cover (top) of document">Top</a>]</td> <td valign="middle" align="left">[<a href="libunistring.html#SEC_Contents" title="Table of contents">Contents</a>]</td> -<td valign="middle" align="left">[<a href="libunistring_18.html#SEC71" title="Index">Index</a>]</td> +<td valign="middle" align="left">[<a href="libunistring_19.html#SEC77" title="Index">Index</a>]</td> <td valign="middle" align="left">[<a href="libunistring_abt.html#SEC_About" title="About (help)"> ? </a>]</td> </tr></table> <hr size="2"> -<a name="uniwbrk_002eh"></a> -<a name="SEC38"></a> -<h1 class="chapter"> <a href="libunistring.html#TOC38">10. Word breaks in strings <code><uniwbrk.h></code></a> </h1> +<a name="unigbrk_002eh"></a> +<a name="SEC41"></a> +<h1 class="chapter"> <a href="libunistring.html#TOC41">10. Grapheme cluster breaks in strings <code><unigbrk.h></code></a> </h1> <p>This include file declares functions for determining where in a string -“words” start and end. Here “words” are not necessarily the same as -entities that can be looked up in dictionaries, but rather groups of -consecutive characters that should not be split by text processing -operations. +“grapheme clusters” start and end. A “grapheme cluster” is an +approximation to a user-perceived character, which sometimes +corresponds to multiple Unicode characters. Editing operations such as +mouse selection, cursor movement, and backspacing often operate on +grapheme clusters as units, not on individual characters. +</p> +<p>Some grapheme clusters are built from a base character and a combining +character. The letter ‘<samp>é</samp>’, +for example, is most commonly represented in Unicode as a single +character U+00E8 <small>LATIN SMALL LETTER E WITH ACUTE</small>. It is, +however, equally valid to use the pair of characters U+0065 <small>LATIN +SMALL LETTER E</small> followed by U+0301 <small>COMBINING ACUTE ACCENT</small>. Since +the user would perceive this pair of characters as a single character, +they would be grouped into a single grapheme cluster. +</p> +<p>But there are also grapheme clusters that consist of several base characters. +For example, a Devanagari letter and a Devanagari vowel sign that follows it +may form a grapheme cluster. Similarly, some pairs of Thai characters and +Hangul syllables (formed by two or three Hangul characters) are grapheme +clusters. </p> <hr size="6"> -<a name="Word-breaks-in-a-string"></a> -<a name="SEC39"></a> -<h2 class="section"> <a href="libunistring.html#TOC39">10.1 Word breaks in a string</a> </h2> +<a name="Grapheme-cluster-breaks-in-a-string"></a> +<a name="SEC42"></a> +<h2 class="section"> <a href="libunistring.html#TOC42">10.1 Grapheme cluster breaks in a string</a> </h2> + +<p>The following functions find a single boundary between grapheme +clusters in a string. +</p> +<dl> +<dt><u>Function:</u> void <b>u8_grapheme_next</b><i> (const uint8_t *<var>s</var>, const uint8_t *<var>end</var>)</i> +<a name="IDX712"></a> +</dt> +<dt><u>Function:</u> void <b>u16_grapheme_next</b><i> (const uint16_t *<var>s</var>, const uint16_t *<var>end</var>)</i> +<a name="IDX713"></a> +</dt> +<dt><u>Function:</u> void <b>u32_grapheme_next</b><i> (const uint32_t *<var>s</var>, const uint32_t *<var>end</var>)</i> +<a name="IDX714"></a> +</dt> +<dd><p>Returns the start of the next grapheme cluster following <var>s</var>, +or <var>end</var> if no grapheme cluster break is encountered before it. +Returns NULL if and only if <code><var>s</var> == <var>end</var></code>. +</p></dd></dl> + +<dl> +<dt><u>Function:</u> void <b>u8_grapheme_prev</b><i> (const uint8_t *<var>s</var>, const uint8_t *<var>start</var>)</i> +<a name="IDX715"></a> +</dt> +<dt><u>Function:</u> void <b>u16_grapheme_prev</b><i> (const uint16_t *<var>s</var>, const uint16_t *<var>start</var>)</i> +<a name="IDX716"></a> +</dt> +<dt><u>Function:</u> void <b>u32_grapheme_prev</b><i> (const uint32_t *<var>s</var>, const uint32_t *<var>start</var>)</i> +<a name="IDX717"></a> +</dt> +<dd><p>Returns the start of the grapheme cluster preceding <var>s</var>, or +<var>start</var> if no grapheme cluster break is encountered before it. +Returns NULL if and only if <code><var>s</var> == <var>start</var></code>. +</p></dd></dl> -<p>The following functions determine the word breaks in a string. +<p>The following functions determine all of the grapheme cluster +boundaries in a string. </p> <dl> -<dt><u>Function:</u> void <b>u8_wordbreaks</b><i> (const uint8_t *<var>s</var>, size_t <var>n</var>, char *<var>p</var>)</i> -<a name="IDX615"></a> +<dt><u>Function:</u> void <b>u8_grapheme_breaks</b><i> (const uint8_t *<var>s</var>, size_t <var>n</var>, char *<var>p</var>)</i> +<a name="IDX718"></a> </dt> -<dt><u>Function:</u> void <b>u16_wordbreaks</b><i> (const uint16_t *<var>s</var>, size_t <var>n</var>, char *<var>p</var>)</i> -<a name="IDX616"></a> +<dt><u>Function:</u> void <b>u16_grapheme_breaks</b><i> (const uint16_t *<var>s</var>, size_t <var>n</var>, char *<var>p</var>)</i> +<a name="IDX719"></a> </dt> -<dt><u>Function:</u> void <b>u32_wordbreaks</b><i> (const uint32_t *<var>s</var>, size_t <var>n</var>, char *<var>p</var>)</i> -<a name="IDX617"></a> +<dt><u>Function:</u> void <b>u32_grapheme_breaks</b><i> (const uint32_t *<var>s</var>, size_t <var>n</var>, char *<var>p</var>)</i> +<a name="IDX720"></a> </dt> -<dt><u>Function:</u> void <b>ulc_wordbreaks</b><i> (const char *<var>s</var>, size_t <var>n</var>, char *<var>p</var>)</i> -<a name="IDX618"></a> +<dt><u>Function:</u> void <b>ulc_grapheme_breaks</b><i> (const char *<var>s</var>, size_t <var>n</var>, char *<var>p</var>)</i> +<a name="IDX721"></a> </dt> -<dd><p>Determines the word break points in <var>s</var>, an array of <var>n</var> units, and -stores the result at <code><var>p</var>[0..<var>n</var>-1]</code>. +<dd><p>Determines the grapheme cluster break points in <var>s</var>, an array of +<var>n</var> units, and stores the result at <code><var>p</var>[0..<var>n</var>-1]</code>. </p><dl compact="compact"> <dt> <code><var>p</var>[i] = 1</code></dt> -<dd><p>means that there is a word boundary between <code><var>s</var>[i-1]</code> and -<code><var>s</var>[i]</code>. +<dd><p>means that there is a grapheme cluster boundary between +<code><var>s</var>[i-1]</code> and <code><var>s</var>[i]</code>. </p></dd> <dt> <code><var>p</var>[i] = 0</code></dt> -<dd><p>means that <code><var>s</var>[i-1]</code> and <code><var>s</var>[i]</code> must not be separated. +<dd><p>means that <code><var>s</var>[i-1]</code> and <code><var>s</var>[i]</code> are part of the +same grapheme cluster. </p></dd> </dl> -<p><code><var>p</var>[0]</code> is always set to 0. If an application wants to consider a -word break to be present at the beginning of the string (before -<code><var>s</var>[0]</code>) or at the end of the string (after -<code><var>s</var>[0..<var>n</var>-1]</code>), it has to treat these cases explicitly. +<p><code><var>p</var>[0]</code> is always set to 1, because there is always a +grapheme cluster break at start of text. </p></dd></dl> <hr size="6"> -<a name="Word-break-property"></a> -<a name="SEC40"></a> -<h2 class="section"> <a href="libunistring.html#TOC40">10.2 Word break property</a> </h2> - -<p>This is a more low-level API. The word break property is a property defined -in Unicode Standard Annex #29, section “Word Boundaries”, see -<a href="http://www.unicode.org/reports/tr29/#Word_Boundaries">http://www.unicode.org/reports/tr29/#Word_Boundaries</a>. It is -used for determining the word breaks in a string. +<a name="Grapheme-cluster-break-property"></a> +<a name="SEC43"></a> +<h2 class="section"> <a href="libunistring.html#TOC43">10.2 Grapheme cluster break property</a> </h2> + +<p>This is a more low-level API. The grapheme cluster break property is a +property defined in Unicode Standard Annex #29, section “Grapheme Cluster +Boundaries”, see +<a href="http://www.unicode.org/reports/tr29/#Grapheme_Cluster_Boundaries">http://www.unicode.org/reports/tr29/#Grapheme_Cluster_Boundaries</a>. +It is used for determining the grapheme cluster breaks in a string. </p> -<p>The following are the possible values of the word break property. More values -may be added in the future. +<p>The following are the possible values of the grapheme cluster break +property. More values may be added in the future. </p> <dl> -<dt><u>Constant:</u> int <b>WBP_OTHER</b> -<a name="IDX619"></a> -</dt> -<dt><u>Constant:</u> int <b>WBP_CR</b> -<a name="IDX620"></a> +<dt><u>Constant:</u> int <b>GBP_OTHER</b> +<a name="IDX722"></a> </dt> -<dt><u>Constant:</u> int <b>WBP_LF</b> -<a name="IDX621"></a> +<dt><u>Constant:</u> int <b>GBP_CR</b> +<a name="IDX723"></a> </dt> -<dt><u>Constant:</u> int <b>WBP_NEWLINE</b> -<a name="IDX622"></a> +<dt><u>Constant:</u> int <b>GBP_LF</b> +<a name="IDX724"></a> </dt> -<dt><u>Constant:</u> int <b>WBP_EXTEND</b> -<a name="IDX623"></a> +<dt><u>Constant:</u> int <b>GBP_CONTROL</b> +<a name="IDX725"></a> </dt> -<dt><u>Constant:</u> int <b>WBP_FORMAT</b> -<a name="IDX624"></a> +<dt><u>Constant:</u> int <b>GBP_EXTEND</b> +<a name="IDX726"></a> </dt> -<dt><u>Constant:</u> int <b>WBP_KATAKANA</b> -<a name="IDX625"></a> +<dt><u>Constant:</u> int <b>GBP_PREPEND</b> +<a name="IDX727"></a> </dt> -<dt><u>Constant:</u> int <b>WBP_ALETTER</b> -<a name="IDX626"></a> +<dt><u>Constant:</u> int <b>GBP_SPACINGMARK</b> +<a name="IDX728"></a> </dt> -<dt><u>Constant:</u> int <b>WBP_MIDNUMLET</b> -<a name="IDX627"></a> +<dt><u>Constant:</u> int <b>GBP_L</b> +<a name="IDX729"></a> </dt> -<dt><u>Constant:</u> int <b>WBP_MIDLETTER</b> -<a name="IDX628"></a> +<dt><u>Constant:</u> int <b>GBP_V</b> +<a name="IDX730"></a> </dt> -<dt><u>Constant:</u> int <b>WBP_MIDNUM</b> -<a name="IDX629"></a> +<dt><u>Constant:</u> int <b>GBP_T</b> +<a name="IDX731"></a> </dt> -<dt><u>Constant:</u> int <b>WBP_NUMERIC</b> -<a name="IDX630"></a> +<dt><u>Constant:</u> int <b>GBP_LV</b> +<a name="IDX732"></a> </dt> -<dt><u>Constant:</u> int <b>WBP_EXTENDNUMLET</b> -<a name="IDX631"></a> +<dt><u>Constant:</u> int <b>GBP_LVT</b> +<a name="IDX733"></a> </dt> </dl> -<p>The following function looks up the word break property of a character. +<p>The following function looks up the grapheme cluster break property of a +character. +</p> +<dl> +<dt><u>Function:</u> int <b>uc_graphemeclusterbreak_property</b><i> (ucs4_t <var>uc</var>)</i> +<a name="IDX734"></a> +</dt> +<dd><p>Returns the Grapheme_Cluster_Break property of a Unicode character. +</p></dd></dl> + +<p>The following function determines whether there is a grapheme cluster +break between two Unicode characters. It is the primitive upon which +the higher-level functions in the previous section are directly based. </p> <dl> -<dt><u>Function:</u> int <b>uc_wordbreak_property</b><i> (ucs4_t <var>uc</var>)</i> -<a name="IDX632"></a> +<dt><u>Function:</u> bool <b>uc_is_grapheme_break</b><i> (ucs4_t <var>a</var>, ucs4_t <var>b</var>)</i> +<a name="IDX735"></a> </dt> -<dd><p>Returns the Word_Break property of a Unicode character. +<dd><p>Returns true if there is an grapheme cluster boundary between Unicode +characters <var>a</var> and <var>b</var>. +</p> +<p>There is always a grapheme cluster break at the start or end of text. +You can specify zero for <var>a</var> or <var>b</var> to indicate start of text or end +of text, respectively. +</p> +<p>This implements the extended (not legacy) grapheme cluster rules +described in the Unicode standard, because the standard says that they +are preferred. </p></dd></dl> <hr size="6"> <table cellpadding="1" cellspacing="1" border="0"> -<tr><td valign="middle" align="left">[<a href="#SEC38" title="Beginning of this chapter or previous chapter"> << </a>]</td> -<td valign="middle" align="left">[<a href="libunistring_11.html#SEC41" title="Next chapter"> >> </a>]</td> +<tr><td valign="middle" align="left">[<a href="#SEC41" title="Beginning of this chapter or previous chapter"> << </a>]</td> +<td valign="middle" align="left">[<a href="libunistring_11.html#SEC44" title="Next chapter"> >> </a>]</td> <td valign="middle" align="left"> </td> <td valign="middle" align="left"> </td> <td valign="middle" align="left"> </td> @@ -178,12 +246,12 @@ may be added in the future. <td valign="middle" align="left"> </td> <td valign="middle" align="left">[<a href="libunistring.html#SEC_Top" title="Cover (top) of document">Top</a>]</td> <td valign="middle" align="left">[<a href="libunistring.html#SEC_Contents" title="Table of contents">Contents</a>]</td> -<td valign="middle" align="left">[<a href="libunistring_18.html#SEC71" title="Index">Index</a>]</td> +<td valign="middle" align="left">[<a href="libunistring_19.html#SEC77" title="Index">Index</a>]</td> <td valign="middle" align="left">[<a href="libunistring_abt.html#SEC_About" title="About (help)"> ? </a>]</td> </tr></table> <p> <font size="-1"> - This document was generated by <em>Bruno Haible</em> on <em>March, 30 2010</em> using <a href="http://www.nongnu.org/texi2html/"><em>texi2html 1.78a</em></a>. + This document was generated by <em>Daiki Ueno</em> on <em>July, 8 2015</em> using <a href="http://www.nongnu.org/texi2html/"><em>texi2html 1.78a</em></a>. </font> <br> |