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<ul><li><a href="../inweb/index.html">inweb</a></li>
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</ul><h2>Foundation Module</h2><ul>
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<!--Weave of 'Writers and Loggers' generated by Inweb-->
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<ul class="crumbs"><li><a href="../index.html">Home</a></li><li><a href="index.html">foundation</a></li><li><a href="index.html#2">Chapter 2: Memory, Streams and Collections</a></li><li><b>Writers and Loggers</b></li></ul><p class="purpose">Formatted text output to streams.</p>
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<ul class="toc"><li><a href="2-wal.html#SP1">§1. Registration</a></li><li><a href="2-wal.html#SP6">§6. Writing</a></li></ul><hr class="tocbar">
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<p class="inwebparagraph"><a id="SP1"></a><b>§1. Registration. </b>The main function here is modelled on the "minimum <code class="display"><span class="extract-syntax">printf</span></code>" function
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used as an example in Kernighan and Ritchie, Chapter 7, but because it
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prints to streams, it combines the traditional functions <code class="display"><span class="extract-syntax">printf</span></code>, <code class="display"><span class="extract-syntax">sprintf</span></code>
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and <code class="display"><span class="extract-syntax">fprintf</span></code> in one. It also contains a number of doohickeys to provide
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for a wider and extensible range of string interpolations.
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</p>
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<p class="inwebparagraph">Traditionally, in the C library, everything in the formatting string is
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literal except for <code class="display"><span class="extract-syntax">%</span></code> escapes: thus <code class="display"><span class="extract-syntax">%d</span></code> means "integer goes here", and
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so on. We follow this but allow extra <code class="display"><span class="extract-syntax">%</span></code> escapes unknown to K&R, and we
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also allow a further family of <code class="display"><span class="extract-syntax">$</span></code> escapes intended for the debugging log
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only; these are restricted to streams flagged as for debugging and generally
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produce guru meditation numbers rather than user-friendly information.
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</p>
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<p class="inwebparagraph">Each escape, say <code class="display"><span class="extract-syntax">%z</span></code>, must be "registered" before use, and will be
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given one of the following categories:
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</p>
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<pre class="definitions">
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<span class="definition-keyword">define</span> <span class="constant-syntax">VACANT_ECAT</span><span class="plain-syntax"> </span><span class="constant-syntax">0</span><span class="plain-syntax"> </span><span class="comment"> unregistered</span>
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<span class="definition-keyword">define</span> <span class="constant-syntax">POINTER_ECAT</span><span class="plain-syntax"> </span><span class="constant-syntax">1</span><span class="plain-syntax"> </span><span class="comment"> data to be printed is a pointer to a structure</span>
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<span class="definition-keyword">define</span> <span class="constant-syntax">INTSIZED_ECAT</span><span class="plain-syntax"> </span><span class="constant-syntax">2</span><span class="plain-syntax"> </span><span class="comment"> data to be printed is or fits into an integer</span>
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<span class="definition-keyword">define</span> <span class="constant-syntax">WORDING_ECAT</span><span class="plain-syntax"> </span><span class="constant-syntax">3</span><span class="plain-syntax"> </span><span class="comment"> data to be printed is a </span><code class="display"><span class="extract-syntax">wording</span></code><span class="comment"> structure from inform7</span>
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<span class="definition-keyword">define</span> <span class="constant-syntax">DIRECT_ECAT</span><span class="plain-syntax"> </span><span class="constant-syntax">4</span><span class="plain-syntax"> </span><span class="comment"> data must be printed directly by the code below</span>
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</pre>
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<p class="inwebparagraph"><a id="SP2"></a><b>§2. </b>We'll start with <code class="display"><span class="extract-syntax">%</span></code> escapes, which generalise the familiar <code class="display"><span class="extract-syntax">printf</span></code>
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escapes such as <code class="display"><span class="extract-syntax">%d</span></code>. Cumbersomely, we need three sorts of escape: those where
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the variable argument token is a pointer, those where it's essentially an
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integer, and those where it's a structure used only in the Inform 7 compiler
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called a <code class="display"><span class="extract-syntax">wording</span></code>. The standard C typechecker can't generalise across these,
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so we have to do everything three times. (And then we have to do all that twice,
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because the loggers don't use format strings.)
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</p>
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<pre class="displayed-code all-displayed-code">
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<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">escapes_registered</span><span class="plain-syntax"> = </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[2][128]; </span><span class="comment"> one of the </span><code class="display"><span class="extract-syntax">*_ECAT</span></code><span class="comment"> values above</span>
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<span class="reserved-syntax">void</span><span class="plain-syntax"> *</span><span class="identifier-syntax">the_escapes</span><span class="plain-syntax">[2][128]; </span><span class="comment"> the function to call to implement this</span>
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<span class="reserved-syntax">typedef</span><span class="plain-syntax"> </span><span class="reserved-syntax">void</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">writer_function</span><span class="plain-syntax">)(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">char</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *);</span>
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<span class="reserved-syntax">typedef</span><span class="plain-syntax"> </span><span class="reserved-syntax">void</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">writer_function_I</span><span class="plain-syntax">)(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">char</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">int</span><span class="plain-syntax">);</span>
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<span class="reserved-syntax">typedef</span><span class="plain-syntax"> </span><span class="reserved-syntax">void</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">log_function</span><span class="plain-syntax">)(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *);</span>
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<span class="reserved-syntax">typedef</span><span class="plain-syntax"> </span><span class="reserved-syntax">void</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">log_function_I</span><span class="plain-syntax">)(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">int</span><span class="plain-syntax">);</span>
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<span class="plain-syntax">#</span><span class="identifier-syntax">ifdef</span><span class="plain-syntax"> </span><span class="identifier-syntax">WORDS_MODULE</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">typedef</span><span class="plain-syntax"> </span><span class="reserved-syntax">void</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">writer_function_W</span><span class="plain-syntax">)(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">char</span><span class="plain-syntax"> *, </span><span class="identifier-syntax">wording</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">typedef</span><span class="plain-syntax"> </span><span class="reserved-syntax">void</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">log_function_W</span><span class="plain-syntax">)(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *, </span><span class="identifier-syntax">wording</span><span class="plain-syntax">);</span>
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<span class="plain-syntax">#</span><span class="identifier-syntax">endif</span>
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</pre><p class="inwebparagraph"><a id="SP3"></a><b>§3. </b></p>
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<pre class="displayed-code all-displayed-code">
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<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Writers::log_escape_usage</span><button class="popup" onclick="togglePopup('usagePopup1')">...<span class="popuptext" id="usagePopup1">Usage of <b>Writers::log_escape_usage</b>:<br>none</span></button><span class="plain-syntax">(</span><span class="reserved-syntax">void</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">cat</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="identifier-syntax">cat</span><span class="plain-syntax"> < </span><span class="constant-syntax">2</span><span class="plain-syntax">; </span><span class="identifier-syntax">cat</span><span class="plain-syntax">++) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">char</span><span class="plain-syntax"> *</span><span class="identifier-syntax">alphanum</span><span class="plain-syntax"> = </span><span class="string-syntax">"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"Vacant escapes: %s: "</span><span class="plain-syntax">, (</span><span class="identifier-syntax">cat</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">)?</span><span class="string-syntax">"%"</span><span class="plain-syntax">:</span><span class="string-syntax">"$"</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">i</span><span class="plain-syntax">=0; </span><span class="identifier-syntax">alphanum</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">]; </span><span class="identifier-syntax">i</span><span class="plain-syntax">++)</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[</span><span class="identifier-syntax">cat</span><span class="plain-syntax">][(</span><span class="reserved-syntax">int</span><span class="plain-syntax">) </span><span class="identifier-syntax">alphanum</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">]] == </span><span class="constant-syntax">VACANT_ECAT</span><span class="plain-syntax">)</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"%c"</span><span class="plain-syntax">, </span><span class="identifier-syntax">alphanum</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">]);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">else</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"."</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"\n"</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> }</span>
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<span class="plain-syntax">}</span>
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</pre><p class="inwebparagraph"><a id="SP4"></a><b>§4. </b>That gives us a number of front doors:
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</p>
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<pre class="displayed-code all-displayed-code">
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<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Writers::register_writer</span><button class="popup" onclick="togglePopup('usagePopup2')">...<span class="popuptext" id="usagePopup2">Usage of <b>Writers::register_writer</b>:<br>Foundation Module - <a href="1-fm.html#SP8_1">§8.1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">esc</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">f</span><span class="plain-syntax">)(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">char</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *)) {</span>
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<span class="plain-syntax"> </span><a href="2-wal.html#SP5" class="internal">Writers::register_writer_p</a><span class="plain-syntax">(0, </span><span class="identifier-syntax">esc</span><span class="plain-syntax">, (</span><span class="reserved-syntax">void</span><span class="plain-syntax"> *) </span><span class="identifier-syntax">f</span><span class="plain-syntax">, </span><span class="constant-syntax">POINTER_ECAT</span><span class="plain-syntax">);</span>
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<span class="plain-syntax">}</span>
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<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Writers::register_logger</span><button class="popup" onclick="togglePopup('usagePopup3')">...<span class="popuptext" id="usagePopup3">Usage of <b>Writers::register_logger</b>:<br>Foundation Module - <a href="1-fm.html#SP8_3">§8.3</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">esc</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">f</span><span class="plain-syntax">)(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *)) {</span>
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<span class="plain-syntax"> </span><a href="2-wal.html#SP5" class="internal">Writers::register_writer_p</a><span class="plain-syntax">(1, </span><span class="identifier-syntax">esc</span><span class="plain-syntax">, (</span><span class="reserved-syntax">void</span><span class="plain-syntax"> *) </span><span class="identifier-syntax">f</span><span class="plain-syntax">, </span><span class="constant-syntax">POINTER_ECAT</span><span class="plain-syntax">);</span>
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<span class="plain-syntax">}</span>
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<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Writers::register_writer_I</span><button class="popup" onclick="togglePopup('usagePopup4')">...<span class="popuptext" id="usagePopup4">Usage of <b>Writers::register_writer_I</b>:<br>none</span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">esc</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">f</span><span class="plain-syntax">)(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">char</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">int</span><span class="plain-syntax">)) {</span>
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<span class="plain-syntax"> </span><a href="2-wal.html#SP5" class="internal">Writers::register_writer_p</a><span class="plain-syntax">(0, </span><span class="identifier-syntax">esc</span><span class="plain-syntax">, (</span><span class="reserved-syntax">void</span><span class="plain-syntax"> *) </span><span class="identifier-syntax">f</span><span class="plain-syntax">, </span><span class="constant-syntax">INTSIZED_ECAT</span><span class="plain-syntax">);</span>
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<span class="plain-syntax">}</span>
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<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Writers::register_logger_I</span><button class="popup" onclick="togglePopup('usagePopup5')">...<span class="popuptext" id="usagePopup5">Usage of <b>Writers::register_logger_I</b>:<br>none</span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">esc</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">f</span><span class="plain-syntax">)(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *, </span><span class="reserved-syntax">int</span><span class="plain-syntax">)) {</span>
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<span class="plain-syntax"> </span><a href="2-wal.html#SP5" class="internal">Writers::register_writer_p</a><span class="plain-syntax">(1, </span><span class="identifier-syntax">esc</span><span class="plain-syntax">, (</span><span class="reserved-syntax">void</span><span class="plain-syntax"> *) </span><span class="identifier-syntax">f</span><span class="plain-syntax">, </span><span class="constant-syntax">INTSIZED_ECAT</span><span class="plain-syntax">);</span>
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<span class="plain-syntax">}</span>
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<span class="plain-syntax">#</span><span class="identifier-syntax">ifdef</span><span class="plain-syntax"> </span><span class="identifier-syntax">WORDS_MODULE</span>
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<span class="plain-syntax">#</span><span class="identifier-syntax">define</span><span class="plain-syntax"> </span><span class="identifier-syntax">Writers::register_writer_W</span><span class="plain-syntax">(</span><span class="identifier-syntax">esc</span><span class="plain-syntax">, </span><span class="identifier-syntax">f</span><span class="plain-syntax">) </span><a href="2-wal.html#SP5" class="internal">Writers::register_writer_p</a><span class="plain-syntax">(0, </span><span class="identifier-syntax">esc</span><span class="plain-syntax">, (</span><span class="reserved-syntax">void</span><span class="plain-syntax"> *) </span><span class="identifier-syntax">f</span><span class="plain-syntax">, </span><span class="constant-syntax">WORDING_ECAT</span><span class="plain-syntax">);</span>
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<span class="plain-syntax">#</span><span class="identifier-syntax">define</span><span class="plain-syntax"> </span><span class="identifier-syntax">Writers::register_logger_W</span><span class="plain-syntax">(</span><span class="identifier-syntax">esc</span><span class="plain-syntax">, </span><span class="identifier-syntax">f</span><span class="plain-syntax">) </span><a href="2-wal.html#SP5" class="internal">Writers::register_writer_p</a><span class="plain-syntax">(1, </span><span class="identifier-syntax">esc</span><span class="plain-syntax">, (</span><span class="reserved-syntax">void</span><span class="plain-syntax"> *) </span><span class="identifier-syntax">f</span><span class="plain-syntax">, </span><span class="constant-syntax">WORDING_ECAT</span><span class="plain-syntax">);</span>
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<span class="plain-syntax">#</span><span class="identifier-syntax">endif</span>
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</pre><p class="inwebparagraph"><a id="SP5"></a><b>§5. </b>All leading to:
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</p>
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<pre class="displayed-code all-displayed-code">
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<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Writers::register_writer_p</span><button class="popup" onclick="togglePopup('usagePopup6')">...<span class="popuptext" id="usagePopup6">Usage of <b>Writers::register_writer_p</b>:<br><a href="2-wal.html#SP4">§4</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">set</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">esc</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *</span><span class="identifier-syntax">f</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">cat</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">escapes_registered</span><span class="plain-syntax"> == </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">) </span><<span class="named-paragraph">Initialise the table of escapes</span> <span class="named-paragraph-number">5.1</span>><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">esc</span><span class="plain-syntax"> < </span><span class="constant-syntax">0</span><span class="plain-syntax">) || (</span><span class="identifier-syntax">esc</span><span class="plain-syntax"> >= </span><span class="constant-syntax">128</span><span class="plain-syntax">) ||</span>
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<span class="plain-syntax"> ((</span><a href="4-chr.html#SP1" class="internal">Characters::isalpha</a><span class="plain-syntax">(</span><span class="identifier-syntax">esc</span><span class="plain-syntax">) == </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">) && (</span><a href="4-chr.html#SP1" class="internal">Characters::isdigit</a><span class="plain-syntax">(</span><span class="identifier-syntax">esc</span><span class="plain-syntax">) == </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">)))</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"nonalphabetic escape"</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[</span><span class="identifier-syntax">set</span><span class="plain-syntax">][</span><span class="identifier-syntax">esc</span><span class="plain-syntax">] != </span><span class="constant-syntax">VACANT_ECAT</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE_TO</span><span class="plain-syntax">(</span><span class="constant-syntax">STDERR</span><span class="plain-syntax">, </span><span class="string-syntax">"Clashing escape is %s%c\n"</span><span class="plain-syntax">, (</span><span class="identifier-syntax">set</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">)?</span><span class="string-syntax">"%"</span><span class="plain-syntax">:</span><span class="string-syntax">"$"</span><span class="plain-syntax">, </span><span class="identifier-syntax">esc</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"clash of escapes"</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[</span><span class="identifier-syntax">set</span><span class="plain-syntax">][</span><span class="identifier-syntax">esc</span><span class="plain-syntax">] = </span><span class="identifier-syntax">cat</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">the_escapes</span><span class="plain-syntax">[</span><span class="identifier-syntax">set</span><span class="plain-syntax">][</span><span class="identifier-syntax">esc</span><span class="plain-syntax">] = </span><span class="identifier-syntax">f</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax">}</span>
|
|
</pre><p class="inwebparagraph"><a id="SP5_1"></a><b>§5.1. </b>We're going to implement <code class="display"><span class="extract-syntax">%d</span></code> and a few others directly, so those are marked
|
|
in the table as being unavailable for registration.
|
|
</p>
|
|
|
|
<p class="inwebparagraph">Note that we don't support <code class="display"><span class="extract-syntax">%f</span></code> for floats; but we do add our very own <code class="display"><span class="extract-syntax">%w</span></code>
|
|
for wide strings.
|
|
</p>
|
|
|
|
|
|
<p class="macrodefinition"><code class="display">
|
|
<<span class="named-paragraph-defn">Initialise the table of escapes</span> <span class="named-paragraph-number">5.1</span>> =
|
|
</code></p>
|
|
|
|
<pre class="displayed-code all-displayed-code">
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_registered</span><span class="plain-syntax"> = </span><span class="constant-syntax">TRUE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">e</span><span class="plain-syntax">=0; </span><span class="identifier-syntax">e</span><span class="plain-syntax"><2; </span><span class="identifier-syntax">e</span><span class="plain-syntax">++)</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">i</span><span class="plain-syntax">=0; </span><span class="identifier-syntax">i</span><span class="plain-syntax"><128; </span><span class="identifier-syntax">i</span><span class="plain-syntax">++) {</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">the_escapes</span><span class="plain-syntax">[</span><span class="identifier-syntax">e</span><span class="plain-syntax">][</span><span class="identifier-syntax">i</span><span class="plain-syntax">] = </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">; </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[</span><span class="identifier-syntax">e</span><span class="plain-syntax">][</span><span class="identifier-syntax">i</span><span class="plain-syntax">] = </span><span class="constant-syntax">VACANT_ECAT</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[0][</span><span class="character-syntax">'c'</span><span class="plain-syntax">] = </span><span class="constant-syntax">DIRECT_ECAT</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[0][</span><span class="character-syntax">'d'</span><span class="plain-syntax">] = </span><span class="constant-syntax">DIRECT_ECAT</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[0][</span><span class="character-syntax">'g'</span><span class="plain-syntax">] = </span><span class="constant-syntax">DIRECT_ECAT</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[0][</span><span class="character-syntax">'i'</span><span class="plain-syntax">] = </span><span class="constant-syntax">DIRECT_ECAT</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[0][</span><span class="character-syntax">'s'</span><span class="plain-syntax">] = </span><span class="constant-syntax">DIRECT_ECAT</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[0][</span><span class="character-syntax">'w'</span><span class="plain-syntax">] = </span><span class="constant-syntax">DIRECT_ECAT</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[0][</span><span class="character-syntax">'x'</span><span class="plain-syntax">] = </span><span class="constant-syntax">DIRECT_ECAT</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[0][</span><span class="character-syntax">'%'</span><span class="plain-syntax">] = </span><span class="constant-syntax">DIRECT_ECAT</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[0][</span><span class="character-syntax">'$'</span><span class="plain-syntax">] = </span><span class="constant-syntax">DIRECT_ECAT</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[1][</span><span class="character-syntax">'%'</span><span class="plain-syntax">] = </span><span class="constant-syntax">DIRECT_ECAT</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[1][</span><span class="character-syntax">'$'</span><span class="plain-syntax">] = </span><span class="constant-syntax">DIRECT_ECAT</span><span class="plain-syntax">;</span>
|
|
</pre><ul class="endnotetexts"><li>This code is used in <a href="2-wal.html#SP5">§5</a>.</li></ul><p class="inwebparagraph"><a id="SP6"></a><b>§6. Writing. </b>We can finally get on with that formatted-print function we've all been
|
|
waiting for:
|
|
</p>
|
|
|
|
<pre class="displayed-code all-displayed-code">
|
|
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Writers::printf</span><button class="popup" onclick="togglePopup('usagePopup7')">...<span class="popuptext" id="usagePopup7">Usage of <b>Writers::printf</b>:<br>Streams - <a href="2-str.html#SP3">§3</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">stream</span><span class="plain-syntax">, </span><span class="reserved-syntax">char</span><span class="plain-syntax"> *</span><span class="identifier-syntax">fmt</span><span class="plain-syntax">, ...) {</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">va_list</span><span class="plain-syntax"> </span><span class="identifier-syntax">ap</span><span class="plain-syntax">; </span><span class="comment"> the variable argument list signified by the dots</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">char</span><span class="plain-syntax"> *</span><span class="identifier-syntax">p</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">stream</span><span class="plain-syntax"> == </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">va_start</span><span class="plain-syntax">(</span><span class="identifier-syntax">ap</span><span class="plain-syntax">, </span><span class="identifier-syntax">fmt</span><span class="plain-syntax">); </span><span class="comment"> macro to begin variable argument processing</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="identifier-syntax">p</span><span class="plain-syntax"> = </span><span class="identifier-syntax">fmt</span><span class="plain-syntax">; *</span><span class="identifier-syntax">p</span><span class="plain-syntax">; </span><span class="identifier-syntax">p</span><span class="plain-syntax">++) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">p</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'%'</span><span class="plain-syntax">: {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">set</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><<span class="named-paragraph">Deal with escape sequences</span> <span class="named-paragraph-number">6.1</span>><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'$'</span><span class="plain-syntax">: {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">set</span><span class="plain-syntax"> = </span><span class="constant-syntax">1</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">stream</span><span class="plain-syntax">-></span><span class="element-syntax">stream_flags</span><span class="plain-syntax">) & </span><span class="constant-syntax">USES_LOG_ESCAPES_STRF</span><span class="plain-syntax">)</span>
|
|
<span class="plain-syntax"> </span><<span class="named-paragraph">Deal with escape sequences</span> <span class="named-paragraph-number">6.1</span>>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><a href="2-str.html#SP35" class="internal">Streams::putc</a><span class="plain-syntax">(</span><span class="character-syntax">'$'</span><span class="plain-syntax">, </span><span class="identifier-syntax">stream</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'"'</span><span class="plain-syntax">:</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">stream</span><span class="plain-syntax">-></span><span class="element-syntax">stream_flags</span><span class="plain-syntax"> & </span><span class="constant-syntax">USES_I6_ESCAPES_STRF</span><span class="plain-syntax">)</span>
|
|
<span class="plain-syntax"> </span><a href="2-str.html#SP35" class="internal">Streams::putc</a><span class="plain-syntax">(</span><span class="character-syntax">'~'</span><span class="plain-syntax">, </span><span class="identifier-syntax">stream</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><a href="2-str.html#SP35" class="internal">Streams::putc</a><span class="plain-syntax">(*</span><span class="identifier-syntax">p</span><span class="plain-syntax">, </span><span class="identifier-syntax">stream</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'\n'</span><span class="plain-syntax">:</span>
|
|
<span class="plain-syntax"> </span><a href="2-str.html#SP35" class="internal">Streams::putc</a><span class="plain-syntax">(*</span><span class="identifier-syntax">p</span><span class="plain-syntax">, </span><span class="identifier-syntax">stream</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">default:</span><span class="plain-syntax"> </span><a href="2-str.html#SP35" class="internal">Streams::putc</a><span class="plain-syntax">(*</span><span class="identifier-syntax">p</span><span class="plain-syntax">, </span><span class="identifier-syntax">stream</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">va_end</span><span class="plain-syntax">(</span><span class="identifier-syntax">ap</span><span class="plain-syntax">); </span><span class="comment"> macro to end variable argument processing</span>
|
|
<span class="plain-syntax">}</span>
|
|
</pre><p class="inwebparagraph"><a id="SP6_1"></a><b>§6.1. </b><code class="display">
|
|
<<span class="named-paragraph-defn">Deal with escape sequences</span> <span class="named-paragraph-number">6.1</span>> =
|
|
</code></p>
|
|
|
|
<pre class="displayed-code all-displayed-code">
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">char</span><span class="plain-syntax"> </span><span class="identifier-syntax">format_string</span><span class="plain-syntax">[8];</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">esc_number</span><span class="plain-syntax"> = </span><span class="character-syntax">' '</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">i</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">format_string</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">++] = *(</span><span class="identifier-syntax">p</span><span class="plain-syntax">++);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">while</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">p</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">format_string</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">++] = *</span><span class="identifier-syntax">p</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">islower</span><span class="plain-syntax">(*</span><span class="identifier-syntax">p</span><span class="plain-syntax">)) || (</span><span class="identifier-syntax">isupper</span><span class="plain-syntax">(*</span><span class="identifier-syntax">p</span><span class="plain-syntax">)) || ((</span><span class="identifier-syntax">set</span><span class="plain-syntax"> == </span><span class="constant-syntax">1</span><span class="plain-syntax">) && (</span><span class="identifier-syntax">isdigit</span><span class="plain-syntax">(*</span><span class="identifier-syntax">p</span><span class="plain-syntax">))) ||</span>
|
|
<span class="plain-syntax"> (*</span><span class="identifier-syntax">p</span><span class="plain-syntax"> == </span><span class="character-syntax">'%'</span><span class="plain-syntax">)) </span><span class="identifier-syntax">esc_number</span><span class="plain-syntax"> = (</span><span class="reserved-syntax">int</span><span class="plain-syntax">) *</span><span class="identifier-syntax">p</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">p</span><span class="plain-syntax">++;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">esc_number</span><span class="plain-syntax"> != </span><span class="character-syntax">' '</span><span class="plain-syntax">) || (</span><span class="identifier-syntax">i</span><span class="plain-syntax">==6)) </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">format_string</span><span class="plain-syntax">[</span><span class="identifier-syntax">i</span><span class="plain-syntax">] = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="identifier-syntax">p</span><span class="plain-syntax">--;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">esc_number</span><span class="plain-syntax"><0) || (</span><span class="identifier-syntax">esc_number</span><span class="plain-syntax"> > </span><span class="constant-syntax">255</span><span class="plain-syntax">)) </span><span class="identifier-syntax">esc_number</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="identifier-syntax">escapes_category</span><span class="plain-syntax">[</span><span class="identifier-syntax">set</span><span class="plain-syntax">][</span><span class="identifier-syntax">esc_number</span><span class="plain-syntax">]) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">POINTER_ECAT:</span><span class="plain-syntax"> {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">set</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">writer_function</span><span class="plain-syntax"> </span><span class="identifier-syntax">f</span><span class="plain-syntax"> = (</span><span class="identifier-syntax">writer_function</span><span class="plain-syntax">) </span><span class="identifier-syntax">the_escapes</span><span class="plain-syntax">[0][</span><span class="identifier-syntax">esc_number</span><span class="plain-syntax">];</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *</span><span class="identifier-syntax">q</span><span class="plain-syntax"> = </span><span class="identifier-syntax">va_arg</span><span class="plain-syntax">(</span><span class="identifier-syntax">ap</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *);</span>
|
|
<span class="plain-syntax"> (*</span><span class="identifier-syntax">f</span><span class="plain-syntax">)(</span><span class="identifier-syntax">stream</span><span class="plain-syntax">, </span><span class="identifier-syntax">format_string</span><span class="plain-syntax">+1, </span><span class="identifier-syntax">q</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">log_function</span><span class="plain-syntax"> </span><span class="identifier-syntax">f</span><span class="plain-syntax"> = (</span><span class="identifier-syntax">log_function</span><span class="plain-syntax">) </span><span class="identifier-syntax">the_escapes</span><span class="plain-syntax">[1][</span><span class="identifier-syntax">esc_number</span><span class="plain-syntax">];</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *</span><span class="identifier-syntax">q</span><span class="plain-syntax"> = </span><span class="identifier-syntax">va_arg</span><span class="plain-syntax">(</span><span class="identifier-syntax">ap</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *);</span>
|
|
<span class="plain-syntax"> (*</span><span class="identifier-syntax">f</span><span class="plain-syntax">)(</span><span class="identifier-syntax">stream</span><span class="plain-syntax">, </span><span class="identifier-syntax">q</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INTSIZED_ECAT:</span><span class="plain-syntax"> {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">set</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">writer_function_I</span><span class="plain-syntax"> </span><span class="identifier-syntax">f</span><span class="plain-syntax"> = (</span><span class="identifier-syntax">writer_function_I</span><span class="plain-syntax">) </span><span class="identifier-syntax">the_escapes</span><span class="plain-syntax">[0][</span><span class="identifier-syntax">esc_number</span><span class="plain-syntax">];</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">N</span><span class="plain-syntax"> = </span><span class="identifier-syntax">va_arg</span><span class="plain-syntax">(</span><span class="identifier-syntax">ap</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> (*</span><span class="identifier-syntax">f</span><span class="plain-syntax">)(</span><span class="identifier-syntax">stream</span><span class="plain-syntax">, </span><span class="identifier-syntax">format_string</span><span class="plain-syntax">+1, </span><span class="identifier-syntax">N</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
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|
<span class="plain-syntax"> </span><span class="identifier-syntax">log_function_I</span><span class="plain-syntax"> </span><span class="identifier-syntax">f</span><span class="plain-syntax"> = (</span><span class="identifier-syntax">log_function_I</span><span class="plain-syntax">) </span><span class="identifier-syntax">the_escapes</span><span class="plain-syntax">[1][</span><span class="identifier-syntax">esc_number</span><span class="plain-syntax">];</span>
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|
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">N</span><span class="plain-syntax"> = </span><span class="identifier-syntax">va_arg</span><span class="plain-syntax">(</span><span class="identifier-syntax">ap</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> (*</span><span class="identifier-syntax">f</span><span class="plain-syntax">)(</span><span class="identifier-syntax">stream</span><span class="plain-syntax">, </span><span class="identifier-syntax">N</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> }</span>
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|
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> }</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">WORDING_ECAT:</span><span class="plain-syntax"> {</span>
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<span class="plain-syntax"> #</span><span class="identifier-syntax">ifdef</span><span class="plain-syntax"> </span><span class="identifier-syntax">WORDS_MODULE</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">set</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) {</span>
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|
<span class="plain-syntax"> </span><span class="identifier-syntax">writer_function_W</span><span class="plain-syntax"> </span><span class="identifier-syntax">f</span><span class="plain-syntax"> = (</span><span class="identifier-syntax">writer_function_W</span><span class="plain-syntax">) </span><span class="identifier-syntax">the_escapes</span><span class="plain-syntax">[0][</span><span class="identifier-syntax">esc_number</span><span class="plain-syntax">];</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">wording</span><span class="plain-syntax"> </span><span class="identifier-syntax">W</span><span class="plain-syntax"> = </span><span class="identifier-syntax">va_arg</span><span class="plain-syntax">(</span><span class="identifier-syntax">ap</span><span class="plain-syntax">, </span><span class="identifier-syntax">wording</span><span class="plain-syntax">);</span>
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|
<span class="plain-syntax"> (*</span><span class="identifier-syntax">f</span><span class="plain-syntax">)(</span><span class="identifier-syntax">stream</span><span class="plain-syntax">, </span><span class="identifier-syntax">format_string</span><span class="plain-syntax">+1, </span><span class="identifier-syntax">W</span><span class="plain-syntax">);</span>
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|
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
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|
<span class="plain-syntax"> </span><span class="identifier-syntax">log_function_W</span><span class="plain-syntax"> </span><span class="identifier-syntax">f</span><span class="plain-syntax"> = (</span><span class="identifier-syntax">log_function_W</span><span class="plain-syntax">) </span><span class="identifier-syntax">the_escapes</span><span class="plain-syntax">[1][</span><span class="identifier-syntax">esc_number</span><span class="plain-syntax">];</span>
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|
<span class="plain-syntax"> </span><span class="identifier-syntax">wording</span><span class="plain-syntax"> </span><span class="identifier-syntax">W</span><span class="plain-syntax"> = </span><span class="identifier-syntax">va_arg</span><span class="plain-syntax">(</span><span class="identifier-syntax">ap</span><span class="plain-syntax">, </span><span class="identifier-syntax">wording</span><span class="plain-syntax">);</span>
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|
<span class="plain-syntax"> (*</span><span class="identifier-syntax">f</span><span class="plain-syntax">)(</span><span class="identifier-syntax">stream</span><span class="plain-syntax">, </span><span class="identifier-syntax">W</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> }</span>
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<span class="plain-syntax"> #</span><span class="identifier-syntax">endif</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> }</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">DIRECT_ECAT:</span><span class="plain-syntax"> </span><<span class="named-paragraph">Implement this using the original printf</span> <span class="named-paragraph-number">6.1.1</span>><span class="plain-syntax">; </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">VACANT_ECAT:</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">WRITE_TO</span><span class="plain-syntax">(</span><span class="constant-syntax">STDERR</span><span class="plain-syntax">, </span><span class="string-syntax">"*** Bad WRITE escape: <%s> ***\n"</span><span class="plain-syntax">, </span><span class="identifier-syntax">format_string</span><span class="plain-syntax">);</span>
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|
<span class="plain-syntax"> </span><span class="identifier-syntax">internal_error</span><span class="plain-syntax">(</span><span class="string-syntax">"Unknown string escape"</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
</pre><ul class="endnotetexts"><li>This code is used in <a href="2-wal.html#SP6">§6</a> (twice).</li></ul><p class="inwebparagraph"><a id="SP6_1_1"></a><b>§6.1.1. </b>Here the traditional C library helps us out with the difficult ones to get
|
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right. We don't trouble to check that correct <code class="display"><span class="extract-syntax">printf</span></code> escapes have been used:
|
|
instead, we pass anything in the form of a percentage sign, followed by
|
|
up to four nonalphabetic modifying characters, followed by an alphabetic
|
|
category character for numerical printing, straight through to <code class="display"><span class="extract-syntax">sprintf</span></code>
|
|
or <code class="display"><span class="extract-syntax">fprintf</span></code>.
|
|
</p>
|
|
|
|
<p class="inwebparagraph">Thus an escape like <code class="display"><span class="extract-syntax">%04d</span></code> is handled by the standard C library, but not
|
|
<code class="display"><span class="extract-syntax">%s</span></code>, which we handle directly. That's for two reasons: first, we want to
|
|
be careful to prevent overruns of memory streams; second, we need to ensure
|
|
that the correct encoding is used when writing to disc. The numerical
|
|
escapes involve only characters whose representation is the same in all our
|
|
file encodings, but expanding <code class="display"><span class="extract-syntax">%s</span></code> does not.
|
|
</p>
|
|
|
|
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<p class="macrodefinition"><code class="display">
|
|
<<span class="named-paragraph-defn">Implement this using the original printf</span> <span class="named-paragraph-number">6.1.1</span>> =
|
|
</code></p>
|
|
|
|
<pre class="displayed-code all-displayed-code">
|
|
<span class="plain-syntax"> #</span><span class="identifier-syntax">pragma</span><span class="plain-syntax"> </span><span class="identifier-syntax">clang</span><span class="plain-syntax"> </span><span class="identifier-syntax">diagnostic</span><span class="plain-syntax"> </span><span class="identifier-syntax">push</span>
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|
<span class="plain-syntax"> #</span><span class="identifier-syntax">pragma</span><span class="plain-syntax"> </span><span class="identifier-syntax">clang</span><span class="plain-syntax"> </span><span class="identifier-syntax">diagnostic</span><span class="plain-syntax"> </span><span class="identifier-syntax">ignored</span><span class="plain-syntax"> </span><span class="string-syntax">"-Wformat-nonliteral"</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="identifier-syntax">esc_number</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'c'</span><span class="plain-syntax">: </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'d'</span><span class="plain-syntax">: </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'i'</span><span class="plain-syntax">: </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'x'</span><span class="plain-syntax">: { /* |</span><span class="reserved-syntax">char</span><span class="plain-syntax">| </span><span class="identifier-syntax">is</span><span class="plain-syntax"> </span><span class="identifier-syntax">promoted</span><span class="plain-syntax"> </span><span class="identifier-syntax">to</span><span class="plain-syntax"> |</span><span class="reserved-syntax">int</span><span class="plain-syntax">| </span><span class="identifier-syntax">in</span><span class="plain-syntax"> </span><span class="identifier-syntax">variable</span><span class="plain-syntax"> </span><span class="identifier-syntax">arguments</span><span class="plain-syntax"> */</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">ival</span><span class="plain-syntax"> = </span><span class="identifier-syntax">va_arg</span><span class="plain-syntax">(</span><span class="identifier-syntax">ap</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">char</span><span class="plain-syntax"> </span><span class="identifier-syntax">temp</span><span class="plain-syntax">[256];</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">snprintf</span><span class="plain-syntax">(</span><span class="identifier-syntax">temp</span><span class="plain-syntax">, </span><span class="constant-syntax">255</span><span class="plain-syntax">, </span><span class="identifier-syntax">format_string</span><span class="plain-syntax">, </span><span class="identifier-syntax">ival</span><span class="plain-syntax">) >= </span><span class="constant-syntax">255</span><span class="plain-syntax">) </span><span class="identifier-syntax">strcpy</span><span class="plain-syntax">(</span><span class="identifier-syntax">temp</span><span class="plain-syntax">, </span><span class="string-syntax">"?"</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">j</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="identifier-syntax">temp</span><span class="plain-syntax">[</span><span class="identifier-syntax">j</span><span class="plain-syntax">]; </span><span class="identifier-syntax">j</span><span class="plain-syntax">++) </span><a href="2-str.html#SP35" class="internal">Streams::putc</a><span class="plain-syntax">(</span><span class="identifier-syntax">temp</span><span class="plain-syntax">[</span><span class="identifier-syntax">j</span><span class="plain-syntax">], </span><span class="identifier-syntax">stream</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'g'</span><span class="plain-syntax">: {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">double</span><span class="plain-syntax"> </span><span class="identifier-syntax">dval</span><span class="plain-syntax"> = </span><span class="identifier-syntax">va_arg</span><span class="plain-syntax">(</span><span class="identifier-syntax">ap</span><span class="plain-syntax">, </span><span class="reserved-syntax">double</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">char</span><span class="plain-syntax"> </span><span class="identifier-syntax">temp</span><span class="plain-syntax">[256];</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">snprintf</span><span class="plain-syntax">(</span><span class="identifier-syntax">temp</span><span class="plain-syntax">, </span><span class="constant-syntax">255</span><span class="plain-syntax">, </span><span class="identifier-syntax">format_string</span><span class="plain-syntax">, </span><span class="identifier-syntax">dval</span><span class="plain-syntax">) >= </span><span class="constant-syntax">255</span><span class="plain-syntax">) </span><span class="identifier-syntax">strcpy</span><span class="plain-syntax">(</span><span class="identifier-syntax">temp</span><span class="plain-syntax">, </span><span class="string-syntax">"?"</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">j</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="identifier-syntax">temp</span><span class="plain-syntax">[</span><span class="identifier-syntax">j</span><span class="plain-syntax">]; </span><span class="identifier-syntax">j</span><span class="plain-syntax">++) </span><a href="2-str.html#SP35" class="internal">Streams::putc</a><span class="plain-syntax">(</span><span class="identifier-syntax">temp</span><span class="plain-syntax">[</span><span class="identifier-syntax">j</span><span class="plain-syntax">], </span><span class="identifier-syntax">stream</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'s'</span><span class="plain-syntax">:</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">char</span><span class="plain-syntax"> *</span><span class="identifier-syntax">sval</span><span class="plain-syntax"> = </span><span class="identifier-syntax">va_arg</span><span class="plain-syntax">(</span><span class="identifier-syntax">ap</span><span class="plain-syntax">, </span><span class="reserved-syntax">char</span><span class="plain-syntax"> *); *</span><span class="identifier-syntax">sval</span><span class="plain-syntax">; </span><span class="identifier-syntax">sval</span><span class="plain-syntax">++) </span><a href="2-str.html#SP35" class="internal">Streams::putc</a><span class="plain-syntax">(*</span><span class="identifier-syntax">sval</span><span class="plain-syntax">, </span><span class="identifier-syntax">stream</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'w'</span><span class="plain-syntax">: {</span>
|
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<span class="plain-syntax"> </span><span class="identifier-syntax">wchar_t</span><span class="plain-syntax"> *</span><span class="identifier-syntax">W</span><span class="plain-syntax"> = (</span><span class="identifier-syntax">wchar_t</span><span class="plain-syntax"> *) </span><span class="identifier-syntax">va_arg</span><span class="plain-syntax">(</span><span class="identifier-syntax">ap</span><span class="plain-syntax">, </span><span class="identifier-syntax">wchar_t</span><span class="plain-syntax"> *);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax"> (</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">j</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="identifier-syntax">W</span><span class="plain-syntax">[</span><span class="identifier-syntax">j</span><span class="plain-syntax">]; </span><span class="identifier-syntax">j</span><span class="plain-syntax">++) </span><a href="2-str.html#SP35" class="internal">Streams::putc</a><span class="plain-syntax">(</span><span class="identifier-syntax">W</span><span class="plain-syntax">[</span><span class="identifier-syntax">j</span><span class="plain-syntax">], </span><span class="identifier-syntax">stream</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'%'</span><span class="plain-syntax">: </span><a href="2-str.html#SP35" class="internal">Streams::putc</a><span class="plain-syntax">(</span><span class="character-syntax">'%'</span><span class="plain-syntax">, </span><span class="identifier-syntax">stream</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="character-syntax">'$'</span><span class="plain-syntax">: </span><a href="2-str.html#SP35" class="internal">Streams::putc</a><span class="plain-syntax">(</span><span class="character-syntax">'$'</span><span class="plain-syntax">, </span><span class="identifier-syntax">stream</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
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<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> #</span><span class="identifier-syntax">pragma</span><span class="plain-syntax"> </span><span class="identifier-syntax">clang</span><span class="plain-syntax"> </span><span class="identifier-syntax">diagnostic</span><span class="plain-syntax"> </span><span class="identifier-syntax">pop</span>
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</pre><ul class="endnotetexts"><li>This code is used in <a href="2-wal.html#SP6_1">§6.1</a>.</li></ul><hr class="tocbar">
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<ul class="toc"><li><a href="2-str.html">Back to 'Streams'</a></li><li><a href="2-mth.html">Continue with 'Methods'</a></li></ul><hr class="tocbar">
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