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<H2><A NAME="SECTION0014440000000000000000"></A>
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12.4.4 Writer Implementations 
</H2>

<P>
Three implementations of the writer object interface are provided as
examples by this module.  Most applications will need to derive new
writer classes from the <tt class=class>NullWriter</tt> class.

<P>
<dl><dt><b><a name="l2h-1966"><tt class=class>NullWriter</tt></a></b> ()
<dd>
A writer which only provides the interface definition; no actions are
taken on any methods.  This should be the base class for all writers
which do not need to inherit any implementation methods.
</dl>

<P>
<dl><dt><b><a name="l2h-1967"><tt class=class>AbstractWriter</tt></a></b> ()
<dd>
A writer which can be used in debugging formatters, but not much
else.  Each method simply announces itself by printing its name and
arguments on standard output.
</dl>

<P>
<dl><dt><b><a name="l2h-1968"><tt class=class>DumbWriter</tt></a></b> (<big>[</big><var>file</var><big>[</big><var>, maxcol<tt> = 72</tt></var><big>]</big><big>]</big>)
<dd>
Simple writer class which writes output on the file object passed in
as <var>file</var> or, if <var>file</var> is omitted, on standard output.  The
output is simply word-wrapped to the number of columns specified by
<var>maxcol</var>.  This class is suitable for reflowing a sequence of
paragraphs.
</dl><p>
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