diff options
| author | Andreas Rottmann <a.rottmann@gmx.at> | 2009-09-14 12:32:44 +0200 |
|---|---|---|
| committer | Andreas Rottmann <a.rottmann@gmx.at> | 2009-09-14 12:32:44 +0200 |
| commit | fa095a4504cbe668e4244547e2c141597bea4ecf (patch) | |
| tree | 06135820a286ffec47804e75fbf8a147e92acd2e /doc/libunistring_12.html | |
Imported Upstream version 0.9.1upstream/0.9.1
Diffstat (limited to 'doc/libunistring_12.html')
| -rw-r--r-- | doc/libunistring_12.html | 507 |
1 files changed, 507 insertions, 0 deletions
diff --git a/doc/libunistring_12.html b/doc/libunistring_12.html new file mode 100644 index 00000000..0bf1e933 --- /dev/null +++ b/doc/libunistring_12.html @@ -0,0 +1,507 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html401/loose.dtd"> +<html> +<!-- Created on July, 1 2009 by texi2html 1.78a --> +<!-- +Written by: Lionel Cons <Lionel.Cons@cern.ch> (original author) + Karl Berry <karl@freefriends.org> + Olaf Bachmann <obachman@mathematik.uni-kl.de> + and many others. +Maintained by: Many creative people. +Send bugs and suggestions to <texi2html-bug@nongnu.org> + +--> +<head> +<title>GNU libunistring: 12. Normalization forms (composition and decomposition) <uninorm.h></title> + +<meta name="description" content="GNU libunistring: 12. Normalization forms (composition and decomposition) <uninorm.h>"> +<meta name="keywords" content="GNU libunistring: 12. Normalization forms (composition and decomposition) <uninorm.h>"> +<meta name="resource-type" content="document"> +<meta name="distribution" content="global"> +<meta name="Generator" content="texi2html 1.78a"> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +<style type="text/css"> +<!-- +a.summary-letter {text-decoration: none} +pre.display {font-family: serif} +pre.format {font-family: serif} +pre.menu-comment {font-family: serif} +pre.menu-preformatted {font-family: serif} +pre.smalldisplay {font-family: serif; font-size: smaller} +pre.smallexample {font-size: smaller} +pre.smallformat {font-family: serif; font-size: smaller} +pre.smalllisp {font-size: smaller} +span.roman {font-family:serif; font-weight:normal;} +span.sansserif {font-family:sans-serif; font-weight:normal;} +ul.toc {list-style: none} +--> +</style> + + +</head> + +<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_11.html#SEC41" title="Beginning of this chapter or previous chapter"> << </a>]</td> +<td valign="middle" align="left">[<a href="libunistring_13.html#SEC48" title="Next chapter"> >> </a>]</td> +<td valign="middle" align="left"> </td> +<td valign="middle" align="left"> </td> +<td valign="middle" align="left"> </td> +<td valign="middle" align="left"> </td> +<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_abt.html#SEC_About" title="About (help)"> ? </a>]</td> +</tr></table> + +<hr size="2"> +<a name="uninorm_002eh"></a> +<a name="SEC42"></a> +<h1 class="chapter"> <a href="libunistring.html#TOC42">12. Normalization forms (composition and decomposition) <code><uninorm.h></code></a> </h1> + +<p>This include file defines functions for transforming Unicode strings to one +of the four normal forms, known as NFC, NFD, NKFC, NFKD. These +transformations involve decomposition and — for NFC and NFKC — composition +of Unicode characters. +</p> + +<hr size="6"> +<a name="Decomposition-of-characters"></a> +<a name="SEC43"></a> +<h2 class="section"> <a href="libunistring.html#TOC43">12.1 Decomposition of Unicode characters</a> </h2> + +<p>The following enumerated values are the possible types of decomposition of a +Unicode character. +</p> +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_CANONICAL</b> +<a name="IDX646"></a> +</dt> +<dd><p>Denotes canonical decomposition. +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_FONT</b> +<a name="IDX647"></a> +</dt> +<dd><p>UCD marker: <code><font></code>. Denotes a font variant (e.g. a blackletter form). +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_NOBREAK</b> +<a name="IDX648"></a> +</dt> +<dd><p>UCD marker: <code><noBreak></code>. +Denotes a no-break version of a space or hyphen. +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_INITIAL</b> +<a name="IDX649"></a> +</dt> +<dd><p>UCD marker: <code><initial></code>. +Denotes an initial presentation form (Arabic). +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_MEDIAL</b> +<a name="IDX650"></a> +</dt> +<dd><p>UCD marker: <code><medial></code>. +Denotes a medial presentation form (Arabic). +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_FINAL</b> +<a name="IDX651"></a> +</dt> +<dd><p>UCD marker: <code><final></code>. +Denotes a final presentation form (Arabic). +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_ISOLATED</b> +<a name="IDX652"></a> +</dt> +<dd><p>UCD marker: <code><isolated></code>. +Denotes an isolated presentation form (Arabic). +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_CIRCLE</b> +<a name="IDX653"></a> +</dt> +<dd><p>UCD marker: <code><circle></code>. +Denotes an encircled form. +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_SUPER</b> +<a name="IDX654"></a> +</dt> +<dd><p>UCD marker: <code><super></code>. +Denotes a superscript form. +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_SUB</b> +<a name="IDX655"></a> +</dt> +<dd><p>UCD marker: <code><sub></code>. +Denotes a subscript form. +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_VERTICAL</b> +<a name="IDX656"></a> +</dt> +<dd><p>UCD marker: <code><vertical></code>. +Denotes a vertical layout presentation form. +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_WIDE</b> +<a name="IDX657"></a> +</dt> +<dd><p>UCD marker: <code><wide></code>. +Denotes a wide (or zenkaku) compatibility character. +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_NARROW</b> +<a name="IDX658"></a> +</dt> +<dd><p>UCD marker: <code><narrow></code>. +Denotes a narrow (or hankaku) compatibility character. +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_SMALL</b> +<a name="IDX659"></a> +</dt> +<dd><p>UCD marker: <code><small></code>. +Denotes a small variant form (CNS compatibility). +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_SQUARE</b> +<a name="IDX660"></a> +</dt> +<dd><p>UCD marker: <code><square></code>. +Denotes a CJK squared font variant. +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_FRACTION</b> +<a name="IDX661"></a> +</dt> +<dd><p>UCD marker: <code><fraction></code>. +Denotes a vulgar fraction form. +</p></dd></dl> + +<dl> +<dt><u>Constant:</u> int <b>UC_DECOMP_COMPAT</b> +<a name="IDX662"></a> +</dt> +<dd><p>UCD marker: <code><compat></code>. +Denotes an otherwise unspecified compatibility character. +</p></dd></dl> + +<p>The following constant denotes the maximum size of decomposition of a single +Unicode character. +</p> +<dl> +<dt><u>Macro:</u> unsigned int <b>UC_DECOMPOSITION_MAX_LENGTH</b> +<a name="IDX663"></a> +</dt> +<dd><p>This macro expands to a constant that is the required size of buffer passed to +the <code>uc_decomposition</code> and <code>uc_canonical_decomposition</code> functions. +</p></dd></dl> + +<p>The following functions decompose a Unicode character. +</p> +<dl> +<dt><u>Function:</u> int <b>uc_decomposition</b><i> (ucs4_t <var>uc</var>, int *<var>decomp_tag</var>, ucs4_t *<var>decomposition</var>)</i> +<a name="IDX664"></a> +</dt> +<dd><p>Returns the character decomposition mapping of the Unicode character <var>uc</var>. +<var>decomposition</var> must point to an array of at least +<code>UC_DECOMPOSITION_MAX_LENGTH</code> <code>ucs_t</code> elements. +</p> +<p>When a decomposition exists, <code><var>decomposition</var>[0..<var>n</var>-1]</code> and +<code>*<var>decomp_tag</var></code> are filled and <var>n</var> is returned. Otherwise -1 is +returned. +</p></dd></dl> + +<dl> +<dt><u>Function:</u> int <b>uc_canonical_decomposition</b><i> (ucs4_t <var>uc</var>, ucs4_t *<var>decomposition</var>)</i> +<a name="IDX665"></a> +</dt> +<dd><p>Returns the canonical character decomposition mapping of the Unicode character +<var>uc</var>. <var>decomposition</var> must point to an array of at least +<code>UC_DECOMPOSITION_MAX_LENGTH</code> <code>ucs_t</code> elements. +</p> +<p>When a decomposition exists, <code><var>decomposition</var>[0..<var>n</var>-1]</code> is filled +and <var>n</var> is returned. Otherwise -1 is returned. +</p></dd></dl> + +<hr size="6"> +<a name="Composition-of-characters"></a> +<a name="SEC44"></a> +<h2 class="section"> <a href="libunistring.html#TOC44">12.2 Composition of Unicode characters</a> </h2> + +<p>The following function composes a Unicode character from two Unicode +characters. +</p> +<dl> +<dt><u>Function:</u> ucs4_t <b>uc_composition</b><i> (ucs4_t <var>uc1</var>, ucs4_t <var>uc2</var>)</i> +<a name="IDX666"></a> +</dt> +<dd><p>Attempts to combine the Unicode characters <var>uc1</var>, <var>uc2</var>. +<var>uc1</var> is known to have canonical combining class 0. +</p> +<p>Returns the combination of <var>uc1</var> and <var>uc2</var>, if it exists. +Returns 0 otherwise. +</p> +<p>Not all decompositions can be recombined using this function. See the Unicode +file ‘<tt>CompositionExclusions.txt</tt>’ for details. +</p></dd></dl> + +<hr size="6"> +<a name="Normalization-of-strings"></a> +<a name="SEC45"></a> +<h2 class="section"> <a href="libunistring.html#TOC45">12.3 Normalization of strings</a> </h2> + +<p>The Unicode standard defines four normalization forms for Unicode strings. +The following type is used to denote a normalization form. +</p> +<dl> +<dt><u>Type:</u> <b>uninorm_t</b> +<a name="IDX667"></a> +</dt> +<dd><p>An object of type <code>uninorm_t</code> denotes a Unicode normalization form. +This is a scalar type; its values can be compared with <code>==</code>. +</p></dd></dl> + +<p>The following constants denote the four normalization forms. +</p> +<dl> +<dt><u>Macro:</u> uninorm_t <b>UNINORM_NFD</b> +<a name="IDX668"></a> +</dt> +<dd><p>Denotes Normalization form D: canonical decomposition. +</p></dd></dl> + +<dl> +<dt><u>Macro:</u> uninorm_t <b>UNINORM_NFC</b> +<a name="IDX669"></a> +</dt> +<dd><p>Normalization form C: canonical decomposition, then canonical composition. +</p></dd></dl> + +<dl> +<dt><u>Macro:</u> uninorm_t <b>UNINORM_NFKD</b> +<a name="IDX670"></a> +</dt> +<dd><p>Normalization form KD: compatibility decomposition. +</p></dd></dl> + +<dl> +<dt><u>Macro:</u> uninorm_t <b>UNINORM_NFKC</b> +<a name="IDX671"></a> +</dt> +<dd><p>Normalization form KC: compatibility decomposition, then canonical composition. +</p></dd></dl> + +<p>The following functions operate on <code>uninorm_t</code> objects. +</p> +<dl> +<dt><u>Function:</u> bool <b>uninorm_is_compat_decomposing</b><i> (uninorm_t <var>nf</var>)</i> +<a name="IDX672"></a> +</dt> +<dd><p>Tests whether the normalization form <var>nf</var> does compatibility decomposition. +</p></dd></dl> + +<dl> +<dt><u>Function:</u> bool <b>uninorm_is_composing</b><i> (uninorm_t <var>nf</var>)</i> +<a name="IDX673"></a> +</dt> +<dd><p>Tests whether the normalization form <var>nf</var> includes canonical composition. +</p></dd></dl> + +<dl> +<dt><u>Function:</u> uninorm_t <b>uninorm_decomposing_form</b><i> (uninorm_t <var>nf</var>)</i> +<a name="IDX674"></a> +</dt> +<dd><p>Returns the decomposing variant of the normalization form <var>nf</var>. +This maps NFC,NFD → NFD and NFKC,NFKD → NFKD. +</p></dd></dl> + +<p>The following functions apply a Unicode normalization form to a Unicode string. +</p> +<dl> +<dt><u>Function:</u> uint8_t * <b>u8_normalize</b><i> (uninorm_t <var>nf</var>, const uint8_t *<var>s</var>, size_t <var>n</var>, uint8_t *<var>resultbuf</var>, size_t *<var>lengthp</var>)</i> +<a name="IDX675"></a> +</dt> +<dt><u>Function:</u> uint16_t * <b>u16_normalize</b><i> (uninorm_t <var>nf</var>, const uint16_t *<var>s</var>, size_t <var>n</var>, uint16_t *<var>resultbuf</var>, size_t *<var>lengthp</var>)</i> +<a name="IDX676"></a> +</dt> +<dt><u>Function:</u> uint32_t * <b>u32_normalize</b><i> (uninorm_t <var>nf</var>, const uint32_t *<var>s</var>, size_t <var>n</var>, uint32_t *<var>resultbuf</var>, size_t *<var>lengthp</var>)</i> +<a name="IDX677"></a> +</dt> +<dd><p>Returns the specified normalization form of a string. +</p></dd></dl> + +<hr size="6"> +<a name="Normalizing-comparisons"></a> +<a name="SEC46"></a> +<h2 class="section"> <a href="libunistring.html#TOC46">12.4 Normalizing comparisons</a> </h2> + +<p>The following functions compare Unicode string, ignoring differences in +normalization. +</p> +<dl> +<dt><u>Function:</u> int <b>u8_normcmp</b><i> (const uint8_t *<var>s1</var>, size_t <var>n1</var>, const uint8_t *<var>s2</var>, size_t <var>n2</var>, uninorm_t <var>nf</var>, int *<var>resultp</var>)</i> +<a name="IDX678"></a> +</dt> +<dt><u>Function:</u> int <b>u16_normcmp</b><i> (const uint16_t *<var>s1</var>, size_t <var>n1</var>, const uint16_t *<var>s2</var>, size_t <var>n2</var>, uninorm_t <var>nf</var>, int *<var>resultp</var>)</i> +<a name="IDX679"></a> +</dt> +<dt><u>Function:</u> int <b>u32_normcmp</b><i> (const uint32_t *<var>s1</var>, size_t <var>n1</var>, const uint32_t *<var>s2</var>, size_t <var>n2</var>, uninorm_t <var>nf</var>, int *<var>resultp</var>)</i> +<a name="IDX680"></a> +</dt> +<dd><p>Compares <var>s1</var> and <var>s2</var>, ignoring differences in normalization. +</p> +<p><var>nf</var> must be either <code>UNINORM_NFD</code> or <code>UNINORM_NFKD</code>. +</p> +<p>If successful, sets <code>*<var>resultp</var></code> to -1 if <var>s1</var> < <var>s2</var>, +0 if <var>s1</var> = <var>s2</var>, 1 if <var>s1</var> > <var>s2</var>, and returns 0. +Upon failure, returns -1 with <code>errno</code> set. +</p></dd></dl> + +<a name="IDX681"></a> +<a name="IDX682"></a> +<dl> +<dt><u>Function:</u> char * <b>u8_normxfrm</b><i> (const uint8_t *<var>s</var>, size_t <var>n</var>, uninorm_t <var>nf</var>, char *<var>resultbuf</var>, size_t *<var>lengthp</var>)</i> +<a name="IDX683"></a> +</dt> +<dt><u>Function:</u> char * <b>u16_normxfrm</b><i> (const uint16_t *<var>s</var>, size_t <var>n</var>, uninorm_t <var>nf</var>, char *<var>resultbuf</var>, size_t *<var>lengthp</var>)</i> +<a name="IDX684"></a> +</dt> +<dt><u>Function:</u> char * <b>u32_normxfrm</b><i> (const uint32_t *<var>s</var>, size_t <var>n</var>, uninorm_t <var>nf</var>, char *<var>resultbuf</var>, size_t *<var>lengthp</var>)</i> +<a name="IDX685"></a> +</dt> +<dd><p>Converts the string <var>s</var> of length <var>n</var> to a NUL-terminated byte +sequence, in such a way that comparing <code>u8_normxfrm (<var>s1</var>)</code> and +<code>u8_normxfrm (<var>s2</var>)</code> with the <code>u8_cmp2</code> function is equivalent to +comparing <var>s1</var> and <var>s2</var> with the <code>u8_normcoll</code> function. +</p> +<p><var>nf</var> must be either <code>UNINORM_NFC</code> or <code>UNINORM_NFKC</code>. +</p></dd></dl> + +<dl> +<dt><u>Function:</u> int <b>u8_normcoll</b><i> (const uint8_t *<var>s1</var>, size_t <var>n1</var>, const uint8_t *<var>s2</var>, size_t <var>n2</var>, uninorm_t <var>nf</var>, int *<var>resultp</var>)</i> +<a name="IDX686"></a> +</dt> +<dt><u>Function:</u> int <b>u16_normcoll</b><i> (const uint16_t *<var>s1</var>, size_t <var>n1</var>, const uint16_t *<var>s2</var>, size_t <var>n2</var>, uninorm_t <var>nf</var>, int *<var>resultp</var>)</i> +<a name="IDX687"></a> +</dt> +<dt><u>Function:</u> int <b>u32_normcoll</b><i> (const uint32_t *<var>s1</var>, size_t <var>n1</var>, const uint32_t *<var>s2</var>, size_t <var>n2</var>, uninorm_t <var>nf</var>, int *<var>resultp</var>)</i> +<a name="IDX688"></a> +</dt> +<dd><p>Compares <var>s1</var> and <var>s2</var>, ignoring differences in normalization, using +the collation rules of the current locale. +</p> +<p><var>nf</var> must be either <code>UNINORM_NFC</code> or <code>UNINORM_NFKC</code>. +</p> +<p>If successful, sets <code>*<var>resultp</var></code> to -1 if <var>s1</var> < <var>s2</var>, +0 if <var>s1</var> = <var>s2</var>, 1 if <var>s1</var> > <var>s2</var>, and returns 0. +Upon failure, returns -1 with <code>errno</code> set. +</p></dd></dl> + +<hr size="6"> +<a name="Normalization-of-streams"></a> +<a name="SEC47"></a> +<h2 class="section"> <a href="libunistring.html#TOC47">12.5 Normalization of streams of Unicode characters</a> </h2> + +<p>A “stream of Unicode characters” is essentially a function that accepts an +<code>ucs4_t</code> argument repeatedly, optionally combined with a function that +“flushes” the stream. +</p> +<dl> +<dt><u>Type:</u> <b>struct uninorm_filter</b> +<a name="IDX689"></a> +</dt> +<dd><p>This is the data type of a stream of Unicode characters that normalizes its +input according to a given normalization form and passes the normalized +character sequence to the encapsulated stream of Unicode characters. +</p></dd></dl> + +<dl> +<dt><u>Function:</u> struct uninorm_filter * <b>uninorm_filter_create</b><i> (uninorm_t <var>nf</var>, int (*<var>stream_func</var>) (void *<var>stream_data</var>, ucs4_t <var>uc</var>), void *<var>stream_data</var>)</i> +<a name="IDX690"></a> +</dt> +<dd><p>Creates and returns a normalization filter for Unicode characters. +</p> +<p>The pair (<var>stream_func</var>, <var>stream_data</var>) is the encapsulated stream. +<code><var>stream_func</var> (<var>stream_data</var>, <var>uc</var>)</code> receives the Unicode +character <var>uc</var> and returns 0 if successful, or -1 with <code>errno</code> set +upon failure. +</p> +<p>Returns the new filter, or NULL with <code>errno</code> set upon failure. +</p></dd></dl> + +<dl> +<dt><u>Function:</u> int <b>uninorm_filter_write</b><i> (struct uninorm_filter *<var>filter</var>, ucs4_t <var>uc</var>)</i> +<a name="IDX691"></a> +</dt> +<dd><p>Stuffs a Unicode character into a normalizing filter. +Returns 0 if successful, or -1 with <code>errno</code> set upon failure. +</p></dd></dl> + +<dl> +<dt><u>Function:</u> int <b>uninorm_filter_flush</b><i> (struct uninorm_filter *<var>filter</var>)</i> +<a name="IDX692"></a> +</dt> +<dd><p>Brings data buffered in the filter to its destination, the encapsulated stream. +</p> +<p>Returns 0 if successful, or -1 with <code>errno</code> set upon failure. +</p> +<p>Note! If after calling this function, additional characters are written +into the filter, the resulting character sequence in the encapsulated stream +will not necessarily be normalized. +</p></dd></dl> + +<dl> +<dt><u>Function:</u> int <b>uninorm_filter_free</b><i> (struct uninorm_filter *<var>filter</var>)</i> +<a name="IDX693"></a> +</dt> +<dd><p>Brings data buffered in the filter to its destination, the encapsulated stream, +then closes and frees the filter. +</p> +<p>Returns 0 if successful, or -1 with <code>errno</code> set upon failure. +</p></dd></dl> +<hr size="6"> +<table cellpadding="1" cellspacing="1" border="0"> +<tr><td valign="middle" align="left">[<a href="#SEC42" title="Beginning of this chapter or previous chapter"> << </a>]</td> +<td valign="middle" align="left">[<a href="libunistring_13.html#SEC48" title="Next chapter"> >> </a>]</td> +<td valign="middle" align="left"> </td> +<td valign="middle" align="left"> </td> +<td valign="middle" align="left"> </td> +<td valign="middle" align="left"> </td> +<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_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>July, 1 2009</em> using <a href="http://www.nongnu.org/texi2html/"><em>texi2html 1.78a</em></a>. + </font> + <br> + +</p> +</body> +</html> |