修改文件，添加注释

Author: zuyue

postgresql/doc/src/sgml/libpq.sgml

@@ -1,38 +1,103 @@
 <!-- doc/src/sgml/unaccent.sgml -->
 
 <sect1 id="unaccent" xreflabel="unaccent">
+<!--==========================orignal english content==========================
+ <title>unaccent</title>
+____________________________________________________________________________-->
  <title>unaccent</title>
 
+<!--==========================orignal english content==========================
+ <indexterm zone="unaccent">
+  <primary>unaccent</primary>
+ </indexterm>
+____________________________________________________________________________-->
  <indexterm zone="unaccent">
   <primary>unaccent</primary>
  </indexterm>
 
+<!--==========================orignal english content==========================
+ <para>
+  <filename>unaccent</> is a text search dictionary that removes accents
+  (diacritic signs) from lexemes.
+  It's a filtering dictionary, which means its output is
+  always passed to the next dictionary (if any), unlike the normal
+  behavior of dictionaries.  This allows accent-insensitive processing
+  for full text search.
+ </para>
+____________________________________________________________________________-->
  <para>
   <filename>unaccent</>是一个文本搜索字典，它能从词位中移除重音（附加符号）。它是一个过滤词典，这表示它的输出总是会被传递给下一个字典（如果有），这和字典的通常行为不同。这允许为全文搜索做与重音无关的处理。
  </para>
 
+<!--==========================orignal english content==========================
+ <para>
+  The current implementation of <filename>unaccent</> cannot be used as a
+  normalizing dictionary for the <filename>thesaurus</filename> dictionary.
+ </para>
+____________________________________________________________________________-->
  <para>
   <filename>unaccent</>的当前实现不能被用作<filename>thesaurus</filename>字典的正规化字典。
  </para>
 
  <sect2>
+<!--==========================orignal english content==========================
+  <title>Configuration</title>
+____________________________________________________________________________-->
   <title>配置</title>
 
+<!--==========================orignal english content==========================
+  <para>
+   An <literal>unaccent</> dictionary accepts the following options:
+  </para>
+____________________________________________________________________________-->
   <para>
    <literal>unaccent</>字典接受下列选项：
   </para>
   <itemizedlist>
    <listitem>
+<!--==========================orignal english content==========================
+    <para>
+     <literal>RULES</> is the base name of the file containing the list of
+     translation rules.  This file must be stored in
+     <filename>$SHAREDIR/tsearch_data/</> (where <literal>$SHAREDIR</> means
+     the <productname>PostgreSQL</> installation's shared-data directory).
+     Its name must end in <literal>.rules</> (which is not to be included in
+     the <literal>RULES</> parameter).
+    </para>
+____________________________________________________________________________-->
     <para>
      <literal>RULES</>是包含翻译规则列表的文件的基本名。这个文件必须被存储在<filename>$SHAREDIR/tsearch_data/</>（这里<literal>$SHAREDIR</>表示<productname>PostgreSQL</>安装的共享数据目录）中。它的名称必须以<literal>.rules</>（不包含在<literal>RULES</>参数中）结束。
     </para>
    </listitem>
   </itemizedlist>
+<!--==========================orignal english content==========================
+  <para>
+   The rules file has the following format:
+  </para>
+____________________________________________________________________________-->
   <para>
    规则文件具有下面的格式：
   </para>
   <itemizedlist>
    <listitem>
+<!--==========================orignal english content==========================
+    <para>
+     Each line represents one translation rule, consisting of a character with
+     accent followed by a character without accent.  The first is translated
+     into the second.  For example,
+<programlisting>
+&Agrave;        A
+&Aacute;        A
+&Acirc;        A
+&Atilde;        A
+&Auml;        A
+&Aring;        A
+&AElig;        AE
+</programlisting>
+     The two characters must be separated by whitespace, and any leading or
+     trailing whitespace on a line is ignored.
+    </para>
+____________________________________________________________________________-->
     <para>
      每一行表示一个由带有重音的字符和不带重音的字符构成的对。第一个字符将被翻译成第二个。例如：
 <programlisting>
@@ -42,20 +107,97 @@
 &Atilde;        A
 &Auml;        A
 &Aring;        A
-&AElig;        A
+&AElig;        AE
 </programlisting>
+     两个字符必须由空格分隔，并且一行上的任何前导或尾随空白都将被忽略。
+    </para>
+   </listitem>
+
+   <listitem>
+<!--==========================orignal english content==========================
+    <para>
+     Alternatively, if only one character is given on a line, instances of
+     that character are deleted; this is useful in languages where accents
+     are represented by separate characters.
+    </para>
+____________________________________________________________________________-->
+    <para>
+     或者，如果一行只给出一个字符，则删除该字符的实例; 
+     这在用单独的字符表示重音的语言中是有用的。
+    </para>
+   </listitem>
+
+   <listitem>
+<!--==========================orignal english content==========================
+    <para>
+     Actually, each <quote>character</> can be any string not containing
+     whitespace, so <filename>unaccent</> dictionaries could be used for
+     other sorts of substring substitutions besides diacritic removal.
+    </para>
+____________________________________________________________________________-->
+    <para>
+     实际上，每个<quote>字符</>可以是不包含空格的任何字符串，因此，
+     除了去除变音符之外，<filename>unaccent</>字典也可以用于其他类型的字符串替换。
+    </para>
+   </listitem>
+
+   <listitem>
+<!--==========================orignal english content==========================
+    <para>
+     As with other <productname>PostgreSQL</> text search configuration files,
+     the rules file must be stored in UTF-8 encoding.  The data is
+     automatically translated into the current database's encoding when
+     loaded.  Any lines containing untranslatable characters are silently
+     ignored, so that rules files can contain rules that are not applicable in
+     the current encoding.
+    </para>
+____________________________________________________________________________-->
+    <para>
+     与其他<productname>PostgreSQL</>文本搜索配置文件一样，
+     规则文件必须以UTF-8编码方式存储。加载时，数据将自动转换为当前数据库的编码。
+     任何含有不可翻译字符的行都将被忽略，因此规则文件可以包含当前编码中不适用的规则。
     </para>
    </listitem>
   </itemizedlist>
 
+<!--==========================orignal english content==========================
+  <para>
+   A more complete example, which is directly useful for most European
+   languages, can be found in <filename>unaccent.rules</>, which is installed
+   in <filename>$SHAREDIR/tsearch_data/</> when the <filename>unaccent</>
+   module is installed.  This rules file translates characters with accents
+   to the same characters without accents, and it also expands ligatures
+   into the equivalent series of simple characters (for example, &AElig; to
+   AE).
+  </para>
+____________________________________________________________________________-->
   <para>
    在<filename>unaccent.rules</>中可以找到一个更完整的例子，它可以直接用于大部分欧洲语言，当<filename>unaccent</>模块被安装时，它被安装在<filename>$SHAREDIR/tsearch_data/</>中。
   </para>
  </sect2>
 
  <sect2>
+<!--==========================orignal english content==========================
+  <title>Usage</title>
+____________________________________________________________________________-->
   <title>用法</title>
 
+<!--==========================orignal english content==========================
+  <para>
+   Installing the <literal>unaccent</> extension creates a text
+   search template <literal>unaccent</> and a dictionary <literal>unaccent</>
+   based on it.  The <literal>unaccent</> dictionary has the default
+   parameter setting <literal>RULES='unaccent'</>, which makes it immediately
+   usable with the standard <filename>unaccent.rules</> file.
+   If you wish, you can alter the parameter, for example
+
+<programlisting>
+mydb=# ALTER TEXT SEARCH DICTIONARY unaccent (RULES='my_rules');
+</programlisting>
+
+   or create new dictionaries based on the template.
+  </para>
+____________________________________________________________________________-->
   <para>
    安装<literal>unaccent</>扩展会创建一个文本搜索模板<literal>unaccent</>和一个基于前者的字典<literal>unaccent</>。<literal>unaccent</>字典有默认的参数设置<literal>RULES='unaccent'</>，这会让该字典使用标准的<filename>unaccent.rules</>文件。如果希望修改该参数，可以
 
@@ -66,6 +208,18 @@ mydb=# ALTER TEXT SEARCH DICTIONARY unaccent (RULES='my_rules');
    或者基于该模板创建新的字典。
   </para>
 
+<!--==========================orignal english content==========================
+  <para>
+   To test the dictionary, you can try:
+<programlisting>
+mydb=# select ts_lexize('unaccent','H&ocirc;tel');
+ ts_lexize
+-&minus;-&minus;-&minus;-&minus;-&minus;-
+ {Hotel}
+(1 row)
+</programlisting>
+  </para>
+____________________________________________________________________________-->
   <para>
    要测试该字典，你可以尝试：
 <programlisting>
@@ -77,6 +231,35 @@ mydb=# select ts_lexize('unaccent','H&ocirc;tel');
 </programlisting>
   </para>
 
+<!--==========================orignal english content==========================
+  <para>
+   Here is an example showing how to insert the
+   <filename>unaccent</> dictionary into a text search configuration:
+<programlisting>
+mydb=# CREATE TEXT SEARCH CONFIGURATION fr ( COPY = french );
+mydb=# ALTER TEXT SEARCH CONFIGURATION fr
+        ALTER MAPPING FOR hword, hword_part, word
+        WITH unaccent, french_stem;
+mydb=# select to_tsvector('fr','H&ocirc;tels de la Mer');
+    to_tsvector
+-&minus;-&minus;-&minus;-&minus;-&minus;-&minus;-&minus;-&minus;-&minus;-
+ 'hotel':1 'mer':4
+(1 row)
+
+mydb=# select to_tsvector('fr','H&ocirc;tel de la Mer') @@ to_tsquery('fr','Hotels');
+ ?column?
+-&minus;-&minus;-&minus;-&minus;-&minus;
+ t
+(1 row)
+
+mydb=# select ts_headline('fr','H&ocirc;tel de la Mer',to_tsquery('fr','Hotels'));
+      ts_headline
+-&minus;-&minus;-&minus;-&minus;-&minus;-&minus;-&minus;-&minus;-&minus;-&minus;-&minus;-&minus;
+ &lt;b&gt;H&ocirc;tel&lt;/b&gt; de la Mer
+(1 row)
+</programlisting>
+  </para>
+____________________________________________________________________________-->
   <para>
    这里是一个展示把<filename>unaccent</>字典插入到一个文本搜索配置的例子：
 <programlisting>
@@ -106,20 +289,61 @@ mydb=# select ts_headline('fr','H&ocirc;tel de la Mer',to_tsquery('fr','Hotels')
  </sect2>
 
  <sect2>
+<!--==========================orignal english content==========================
+ <title>Functions</title>
+____________________________________________________________________________-->
  <title>函数</title>
 
+<!--==========================orignal english content==========================
+ <para>
+  The <function>unaccent()</> function removes accents (diacritic signs) from
+  a given string.  Basically, it's a wrapper around
+  <filename>unaccent</>-type dictionaries, but it can be used outside normal
+  text search contexts.
+ </para>
+____________________________________________________________________________-->
  <para>
   <function>unaccent()</>函数从一个给定的字符串中移除重音（附加符号）。基本上，它是<filename>unaccent</>字典的一个包装器，但是它能在普通的文本搜索环境之外使用。
  </para>
 
+<!--==========================orignal english content==========================
+ <indexterm>
+  <primary>unaccent</primary>
+ </indexterm>
+____________________________________________________________________________-->
  <indexterm>
   <primary>unaccent</primary>
  </indexterm>
 
+<!--==========================orignal english content==========================
 <synopsis>
 unaccent(<optional><replaceable class="PARAMETER">dictionary</replaceable>, </optional> <replaceable class="PARAMETER">string</replaceable>) returns <type>text</type>
 </synopsis>
+____________________________________________________________________________-->
+<synopsis>
+unaccent(<optional><replaceable class="PARAMETER">dictionary</replaceable>, </optional> <replaceable class="PARAMETER">string</replaceable>) returns <type>text</type>
+</synopsis>
+
+<!--==========================orignal english content==========================
+ <para>
+  If the <replaceable class="PARAMETER">dictionary</replaceable> argument is
+  omitted, <literal>unaccent</> is assumed.
+ </para>
+____________________________________________________________________________-->
+ <para>
+  如果省略了<replaceable class="PARAMETER">dictionary</replaceable>参数，
+  则使用<literal>unaccent</>。
+ </para>
 
+<!--==========================orignal english content==========================
+ <para>
+  For example:
+<programlisting>
+SELECT unaccent('unaccent', 'H&ocirc;tel');
+SELECT unaccent('H&ocirc;tel');
+</programlisting>
+ </para>
+____________________________________________________________________________-->
  <para>
   例如：
 <programlisting>