292 lines
40 KiB
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292 lines
40 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<html>
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<head>
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<title>Reporting the Date</title>
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<nav role="navigation">
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<h1><a href="../index.html">
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<img src="../docs-assets/Octagram.png" width=72 height=72">
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</a></h1>
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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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<li><a href="../foundation-module/index.html">foundation</a></li>
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<li><a href="../foundation-test/index.html">foundation-test</a></li>
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</ul><h2>Example Webs</h2><ul>
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<li><a href="../goldbach/index.html">goldbach</a></li>
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<li><a href="../twinprimes/twinprimes.html">twinprimes</a></li>
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<li><a href="index.html"><span class="selectedlink">eastertide</span></a></li>
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</ul><h2>Repository</h2><ul>
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<li><a href="https://github.com/ganelson/inweb"><img src="../docs-assets/github.png" height=18> github</a></li>
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</ul><h2>Related Projects</h2><ul>
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<li><a href="../../../inform/docs/index.html">inform</a></li>
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<li><a href="../../../intest/docs/index.html">intest</a></li>
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</ul>
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<main role="main">
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<!--Weave of 'Reporting the Date' generated by Inweb-->
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<div class="breadcrumbs">
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<ul class="crumbs"><li><a href="../index.html">Home</a></li><li><a href="index.html">Eastertide</a></li><li><b>Reporting the Date</b></li></ul></div>
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<p class="purpose">This is really the whole Eastertide program, in a single section.</p>
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<p class="commentary firstcommentary"><a id="SP1" class="paragraph-anchor"></a><b>§1. </b>This utility, or perhaps futility, is a minimal example of the use of the
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Foundation library, which comes supplied with <a href="../inweb/index.html" class="internal">inweb</a> for the benefit
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of C programs wanting to use it. We will do everything in an unnecessarily
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fancy way, just to give the tires a kick.
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</p>
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<p class="commentary">Any program using Foundation must define this constant:
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</p>
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<pre class="definitions code-font"><span class="definition-keyword">define</span> <span class="constant-syntax">PROGRAM_NAME</span><span class="plain-syntax"> </span><span class="string-syntax">"eastertide"</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP2" class="paragraph-anchor"></a><b>§2. </b>The <span class="extract"><span class="extract-syntax">main</span></span> routine must start and end Foundation, and is not allowed to
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do much after that; but it is allowed to ask if error messages were generated,
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so that it can return conventional Unix return values 0 (okay) or 1 (not okay).
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">main</span><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">argc</span><span class="plain-syntax">, </span><span class="reserved-syntax">char</span><span class="plain-syntax"> *</span><span class="identifier-syntax">argv</span><span class="plain-syntax">[]) {</span>
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<span class="plain-syntax"> </span><a href="../foundation-module/1-fm.html#SP8" class="function-link"><span class="function-syntax">Foundation::start</span></a><span class="plain-syntax">();</span>
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<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="S-rtd.html#SP2_3" class="named-paragraph-link"><span class="named-paragraph">Read the command line</span><span class="named-paragraph-number">2.3</span></a></span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="S-rtd.html#SP2_1" class="named-paragraph-link"><span class="named-paragraph">Write the report to the console</span><span class="named-paragraph-number">2.1</span></a></span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><a href="../foundation-module/1-fm.html#SP9" class="function-link"><span class="function-syntax">Foundation::end</span></a><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><a href="../foundation-module/3-em.html#SP1" class="function-link"><span class="function-syntax">Errors::have_occurred</span></a><span class="plain-syntax">()) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">1</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">return</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>
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</pre>
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<p class="commentary firstcommentary"><a id="SP2_1" class="paragraph-anchor"></a><b>§2.1. </b>The general scheme here is that we read the command line to work out which
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the user is interested in, and store those in memory; but eventually we will
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actually report on them, thus. <span class="extract"><span class="extract-syntax">STDOUT</span></span> is the "text stream" for standard
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output, i.e., writing to it will print to the Terminal or similar console.
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</p>
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<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Write the report to the console</span><span class="named-paragraph-number">2.1</span></span><span class="comment-syntax"> =</span>
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="plain-syntax"> </span><a href="S-rtd.html#SP9" class="function-link"><span class="function-syntax">Main::report_on_years</span></a><span class="plain-syntax">(</span><span class="constant-syntax">STDOUT</span><span class="plain-syntax">);</span>
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</pre>
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<ul class="endnotetexts"><li>This code is used in <a href="S-rtd.html#SP2">§2</a>.</li></ul>
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<p class="commentary firstcommentary"><a id="SP2_2" class="paragraph-anchor"></a><b>§2.2. </b>All this program does is to print the date of Easter on any years requested,
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but we'll give it some command-line options anyway. Foundation will add also
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<span class="extract"><span class="extract-syntax">-help</span></span> and a few others to the mix.
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</p>
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<pre class="definitions code-font"><span class="definition-keyword">enum</span> <span class="constant-syntax">CALENDAR_FILE_CLSW</span>
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<span class="definition-keyword">enum</span> <span class="constant-syntax">QUALIFYING_CLSG</span>
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<span class="definition-keyword">enum</span> <span class="constant-syntax">VERBOSE_CLSW</span>
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<span class="definition-keyword">enum</span> <span class="constant-syntax">AMERICAN_CLSW</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP2_3" class="paragraph-anchor"></a><b>§2.3. </b><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Read the command line</span><span class="named-paragraph-number">2.3</span></span><span class="comment-syntax"> =</span>
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="plain-syntax"> </span><a href="../foundation-module/3-cla.html#SP14" class="function-link"><span class="function-syntax">CommandLine::declare_heading</span></a><span class="plain-syntax">(</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">L</span><span class="string-syntax">"eastertide: an Easter date calculator\n\n"</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">L</span><span class="string-syntax">"usage: eastertide [OPTIONS] year1 year2 ...\n"</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><a href="../foundation-module/3-cla.html#SP5" class="function-link"><span class="function-syntax">CommandLine::declare_switch</span></a><span class="plain-syntax">(</span><span class="constant-syntax">CALENDAR_FILE_CLSW</span><span class="plain-syntax">, </span><span class="identifier-syntax">L</span><span class="string-syntax">"calendar-file"</span><span class="plain-syntax">, </span><span class="constant-syntax">2</span><span class="plain-syntax">,</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">L</span><span class="string-syntax">"specify file X as a list of year requests, one per line"</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><a href="../foundation-module/3-cla.html#SP5" class="function-link"><span class="function-syntax">CommandLine::begin_group</span></a><span class="plain-syntax">(</span><span class="constant-syntax">QUALIFYING_CLSG</span><span class="plain-syntax">, </span><span class="identifier-syntax">I</span><span class="string-syntax">"for qualifying the output"</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><a href="../foundation-module/3-cla.html#SP6" class="function-link"><span class="function-syntax">CommandLine::declare_boolean_switch</span></a><span class="plain-syntax">(</span><span class="constant-syntax">VERBOSE_CLSW</span><span class="plain-syntax">, </span><span class="identifier-syntax">L</span><span class="string-syntax">"verbose"</span><span class="plain-syntax">, </span><span class="constant-syntax">1</span><span class="plain-syntax">,</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">L</span><span class="string-syntax">"print output verbosely"</span><span class="plain-syntax">, </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><a href="../foundation-module/3-cla.html#SP6" class="function-link"><span class="function-syntax">CommandLine::declare_boolean_switch</span></a><span class="plain-syntax">(</span><span class="constant-syntax">AMERICAN_CLSW</span><span class="plain-syntax">, </span><span class="identifier-syntax">L</span><span class="string-syntax">"american"</span><span class="plain-syntax">, </span><span class="constant-syntax">1</span><span class="plain-syntax">,</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">L</span><span class="string-syntax">"print dates in American MM/DD format"</span><span class="plain-syntax">, </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><a href="../foundation-module/3-cla.html#SP5" class="function-link"><span class="function-syntax">CommandLine::end_group</span></a><span class="plain-syntax">();</span>
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<span class="plain-syntax"> </span><a href="../foundation-module/3-cla.html#SP8" class="function-link"><span class="function-syntax">CommandLine::read</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">argc</span><span class="plain-syntax">, </span><span class="identifier-syntax">argv</span><span class="plain-syntax">, </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">, &</span><a href="S-rtd.html#SP4" class="function-link"><span class="function-syntax">Main::switch</span></a><span class="plain-syntax">, &</span><a href="S-rtd.html#SP4" class="function-link"><span class="function-syntax">Main::bareword</span></a><span class="plain-syntax">);</span>
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</pre>
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<ul class="endnotetexts"><li>This code is used in <a href="S-rtd.html#SP2">§2</a>.</li></ul>
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<p class="commentary firstcommentary"><a id="SP3" class="paragraph-anchor"></a><b>§3. </b>That results in dialogue like the following:
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</p>
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<pre class="ConsoleText-displayed-code all-displayed-code code-font">
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<span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-element-syntax">$</span><span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-function-syntax">eastertide</span><span class="ConsoleText-plain-syntax"> 2020</span>
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<span class="ConsoleText-plain-syntax"> 12/4/2020</span>
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<span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-element-syntax">$</span><span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-function-syntax">eastertide</span><span class="ConsoleText-identifier-syntax"> -help</span>
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<span class="ConsoleText-plain-syntax"> eastertide: an Easter date calculator</span>
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<span class="ConsoleText-plain-syntax"> usage: eastertide [OPTIONS] year1 year2 ...</span>
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<span class="ConsoleText-plain-syntax"> -calendar-file X specify file X as a list of year requests, one per line</span>
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<span class="ConsoleText-plain-syntax"> for qualifying the output:</span>
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<span class="ConsoleText-plain-syntax"> -american print dates in American MM/DD format (default is -no-american)</span>
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<span class="ConsoleText-plain-syntax"> -verbose print output verbosely (default is -no-verbose)</span>
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<span class="ConsoleText-plain-syntax"> -at X specify that this tool is installed at X</span>
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<span class="ConsoleText-plain-syntax"> -crash intentionally crash on internal errors, for backtracing</span>
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<span class="ConsoleText-plain-syntax"> -fixtime pretend the time is 11 a.m. on 28 March 2016 for testing</span>
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<span class="ConsoleText-plain-syntax"> -help print this help information</span>
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<span class="ConsoleText-plain-syntax"> -log X write the debugging log to include diagnostics on X</span>
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<span class="ConsoleText-plain-syntax"> -version print out version number</span>
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<span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-element-syntax">$</span><span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-function-syntax">eastertide</span><span class="ConsoleText-identifier-syntax"> -verbose</span><span class="ConsoleText-plain-syntax"> 2021 2022</span>
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<span class="ConsoleText-plain-syntax"> Easter in 2021 falls on 4/4.</span>
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<span class="ConsoleText-plain-syntax"> Easter in 2022 falls on 17/4.</span>
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<span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-element-syntax">$</span><span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-function-syntax">eastertide</span><span class="ConsoleText-plain-syntax"> 1496</span>
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<span class="ConsoleText-plain-syntax"> eastertide: Gregorian calendar only valid from 1582</span>
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<span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-element-syntax">$</span><span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-function-syntax">eastertide</span><span class="ConsoleText-plain-syntax"> 1685 1750</span>
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<span class="ConsoleText-plain-syntax"> 22/4/1685</span>
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<span class="ConsoleText-plain-syntax"> 29/3/1750</span>
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<span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-element-syntax">$</span><span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-function-syntax">eastertide</span><span class="ConsoleText-identifier-syntax"> -calendar-file</span><span class="ConsoleText-plain-syntax"> cal.txt</span>
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<span class="ConsoleText-plain-syntax"> eastertide: cal.txt, line 2: not a year: '1791b'</span>
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<span class="ConsoleText-plain-syntax"> 15/4/1770</span>
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<span class="ConsoleText-plain-syntax"> 15/4/1827</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP4" class="paragraph-anchor"></a><b>§4. </b>So let's get back to how this is done. The Foundation function <a href="../foundation-module/3-cla.html#SP8" class="internal">CommandLine::read</a>
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calls our function <span class="extract"><span class="ConsoleText-extract-syntax">Main::switch</span></span> when any of our three switches is used
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(we don't need to handle the ones Foundation added, only our own); and
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<span class="extract"><span class="ConsoleText-extract-syntax">Main::bareword</span></span> for any other words given on the command line. For example,
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</p>
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<pre class="ConsoleText-displayed-code all-displayed-code code-font">
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<span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-element-syntax">$</span><span class="ConsoleText-plain-syntax"> </span><span class="ConsoleText-function-syntax">eastertide</span><span class="ConsoleText-identifier-syntax"> -american -calendar-file</span><span class="ConsoleText-plain-syntax"> cal.txt 1982 2007</span>
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</pre>
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<p class="commentary">...results in two calls to <span class="extract"><span class="ConsoleText-extract-syntax">Main::switch</span></span>, then two to <span class="extract"><span class="ConsoleText-extract-syntax">Main::bareword</span></span>.
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">verbose_mode</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">american_mode</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">void</span><span class="plain-syntax"> </span><span class="function-syntax">Main::bareword</span><button class="popup" onclick="togglePopup('usagePopup1')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup1">Usage of <span class="code-font"><span class="function-syntax">Main::bareword</span></span>:<br/><a href="S-rtd.html#SP2_3">§2.3</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">id</span><span class="plain-syntax">, </span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">arg</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *</span><span class="identifier-syntax">state</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><a href="S-rtd.html#SP6" class="function-link"><span class="function-syntax">Main::request</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">arg</span><span class="plain-syntax">, </span><span class="identifier-syntax">NULL</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">Main::switch</span><button class="popup" onclick="togglePopup('usagePopup2')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup2">Usage of <span class="code-font"><span class="function-syntax">Main::switch</span></span>:<br/><a href="S-rtd.html#SP2_3">§2.3</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">id</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">val</span><span class="plain-syntax">, </span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">arg</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *</span><span class="identifier-syntax">state</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="identifier-syntax">id</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">VERBOSE_CLSW:</span><span class="plain-syntax"> </span><span class="identifier-syntax">verbose_mode</span><span class="plain-syntax"> = </span><span class="identifier-syntax">val</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">AMERICAN_CLSW:</span><span class="plain-syntax"> </span><span class="identifier-syntax">american_mode</span><span class="plain-syntax"> = </span><span class="identifier-syntax">val</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">CALENDAR_FILE_CLSW:</span><span class="plain-syntax"> </span><span class="named-paragraph-container code-font"><a href="S-rtd.html#SP4_1" class="named-paragraph-link"><span class="named-paragraph">Process calendar file</span><span class="named-paragraph-number">4.1</span></a></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>
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<span class="plain-syntax">}</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP4_1" class="paragraph-anchor"></a><b>§4.1. </b>We will read in the calendar file as soon as it is mentioned:
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</p>
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<p class="commentary"><span class="named-paragraph-container code-font"><span class="named-paragraph-defn">Process calendar file</span><span class="named-paragraph-number">4.1</span></span><span class="comment-syntax"> =</span>
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="plain-syntax"> </span><span class="reserved-syntax">filename</span><span class="plain-syntax"> *</span><span class="identifier-syntax">F</span><span class="plain-syntax"> = </span><a href="../foundation-module/3-fln.html#SP3" class="function-link"><span class="function-syntax">Filenames::from_text</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">arg</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><a href="../foundation-module/4-tf.html#SP5" class="function-link"><span class="function-syntax">TextFiles::read</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">F</span><span class="plain-syntax">, </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">, </span><span class="string-syntax">"can't open calendar file"</span><span class="plain-syntax">,</span>
|
|
<span class="plain-syntax"> </span><span class="constant-syntax">TRUE</span><span class="plain-syntax">, </span><a href="S-rtd.html#SP5" class="function-link"><span class="function-syntax">Main::calendar_line</span></a><span class="plain-syntax">, </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">, </span><span class="identifier-syntax">NULL</span><span class="plain-syntax">);</span>
|
|
</pre>
|
|
<ul class="endnotetexts"><li>This code is used in <a href="S-rtd.html#SP4">§4</a>.</li></ul>
|
|
<p class="commentary firstcommentary"><a id="SP5" class="paragraph-anchor"></a><b>§5. </b>To make this a little more gratuitous, we'll give calendar files some
|
|
syntax. The following function is called on each line in turn; we're going
|
|
to trim white space, ignore blank lines, and also ignore any line beginning
|
|
withn a <span class="extract"><span class="extract-syntax">#</span></span> as being a comment.
|
|
</p>
|
|
|
|
<pre class="displayed-code all-displayed-code code-font">
|
|
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Main::calendar_line</span><button class="popup" onclick="togglePopup('usagePopup3')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup3">Usage of <span class="code-font"><span class="function-syntax">Main::calendar_line</span></span>:<br/><a href="S-rtd.html#SP4_1">§4.1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">line</span><span class="plain-syntax">, </span><span class="reserved-syntax">text_file_position</span><span class="plain-syntax"> *</span><span class="identifier-syntax">tfp</span><span class="plain-syntax">, </span><span class="reserved-syntax">void</span><span class="plain-syntax"> *</span><span class="identifier-syntax">state</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><a href="../foundation-module/4-sm.html#SP24" class="function-link"><span class="function-syntax">Str::trim_white_space</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">line</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="../foundation-module/4-sm.html#SP8" class="function-link"><span class="function-syntax">Str::len</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">line</span><span class="plain-syntax">) == </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="../foundation-module/4-sm.html#SP13" class="function-link"><span class="function-syntax">Str::get_first_char</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">line</span><span class="plain-syntax">) == </span><span class="character-syntax">'#'</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><a href="S-rtd.html#SP6" class="function-link"><span class="function-syntax">Main::request</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">line</span><span class="plain-syntax">, </span><span class="identifier-syntax">tfp</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax">}</span>
|
|
</pre>
|
|
<p class="commentary firstcommentary"><a id="SP6" class="paragraph-anchor"></a><b>§6. </b>And with that done, we can process a request for a year, which comes from
|
|
either the command lihe (in which case <span class="extract"><span class="extract-syntax">tfp</span></span> here is null), or from the
|
|
calendar file (in which case it remembers the filename and line number).
|
|
</p>
|
|
|
|
<pre class="displayed-code all-displayed-code code-font">
|
|
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Main::request</span><button class="popup" onclick="togglePopup('usagePopup4')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup4">Usage of <span class="code-font"><span class="function-syntax">Main::request</span></span>:<br/><a href="S-rtd.html#SP4">§4</a>, <a href="S-rtd.html#SP5">§5</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">year</span><span class="plain-syntax">, </span><span class="reserved-syntax">text_file_position</span><span class="plain-syntax"> *</span><span class="identifier-syntax">tfp</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">bad_digit</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">LOOP_THROUGH_TEXT</span><span class="plain-syntax">(</span><span class="identifier-syntax">pos</span><span class="plain-syntax">, </span><span class="identifier-syntax">year</span><span class="plain-syntax">)</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><a href="../foundation-module/4-chr.html#SP1" class="function-link"><span class="function-syntax">Characters::isdigit</span></a><span class="plain-syntax">(</span><a href="../foundation-module/4-sm.html#SP13" class="function-link"><span class="function-syntax">Str::get</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pos</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">bad_digit</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">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">bad_digit</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">TEMPORARY_TEXT</span><span class="plain-syntax">(</span><span class="identifier-syntax">err</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="identifier-syntax">err</span><span class="plain-syntax">, </span><span class="string-syntax">"not a year: '%S'"</span><span class="plain-syntax">, </span><span class="identifier-syntax">year</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><a href="../foundation-module/3-em.html#SP5" class="function-link"><span class="function-syntax">Errors::in_text_file_S</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">err</span><span class="plain-syntax">, </span><span class="identifier-syntax">tfp</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-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">Y</span><span class="plain-syntax"> = </span><a href="../foundation-module/4-sm.html#SP7" class="function-link"><span class="function-syntax">Str::atoi</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">year</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">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">Y</span><span class="plain-syntax"> < </span><span class="constant-syntax">1582</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><a href="../foundation-module/3-em.html#SP5" class="function-link"><span class="function-syntax">Errors::in_text_file</span></a><span class="plain-syntax">(</span><span class="string-syntax">"Gregorian calendar only valid from 1582"</span><span class="plain-syntax">, </span><span class="identifier-syntax">tfp</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><a href="S-rtd.html#SP8" class="function-link"><span class="function-syntax">Main::new_year</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">Y</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax">}</span>
|
|
</pre>
|
|
<p class="commentary firstcommentary"><a id="SP7" class="paragraph-anchor"></a><b>§7. </b>Now it's time to actually store a request. There are many simpler ways to
|
|
do this, but we want to demonstrate Foundation's objects system in action,
|
|
so we'll wrap each year supplied in an object. First, we have to define an
|
|
ID constant for this new class of object, and use a macro which causes
|
|
Foundation to generate the necessary handling functions:
|
|
</p>
|
|
|
|
<pre class="definitions code-font"><span class="definition-keyword">enum</span> <span class="constant-syntax">year_request_MT</span>
|
|
</pre>
|
|
<pre class="displayed-code all-displayed-code code-font">
|
|
<span class="identifier-syntax">ALLOCATE_INDIVIDUALLY</span><span class="plain-syntax">(</span><span class="reserved-syntax">year_request</span><span class="plain-syntax">)</span>
|
|
</pre>
|
|
<p class="commentary firstcommentary"><a id="SP8" class="paragraph-anchor"></a><b>§8. </b>Now we should define the rather unnecessary structure itself, and then
|
|
a sort of constructor function. We won't need a destructor: we will never
|
|
destroy the years.
|
|
</p>
|
|
|
|
<pre class="displayed-code all-displayed-code code-font">
|
|
<span class="reserved-syntax">typedef</span><span class="plain-syntax"> </span><span class="reserved-syntax">struct</span><span class="plain-syntax"> </span><span class="reserved-syntax">year_request</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">year</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">MEMORY_MANAGEMENT</span>
|
|
<span class="plain-syntax">} </span><span class="reserved-syntax">year_request</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="reserved-syntax">year_request</span><span class="plain-syntax"> *</span><span class="function-syntax">Main::new_year</span><button class="popup" onclick="togglePopup('usagePopup5')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup5">Usage of <span class="code-font"><span class="function-syntax">Main::new_year</span></span>:<br/><a href="S-rtd.html#SP6">§6</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">Y</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">year_request</span><span class="plain-syntax"> *</span><span class="identifier-syntax">YR</span><span class="plain-syntax"> = </span><span class="identifier-syntax">CREATE</span><span class="plain-syntax">(</span><span class="reserved-syntax">year_request</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">YR</span><span class="plain-syntax">-></span><span class="element-syntax">year</span><span class="plain-syntax"> = </span><span class="identifier-syntax">Y</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="identifier-syntax">YR</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax">}</span>
|
|
</pre>
|
|
<ul class="endnotetexts"><li>The structure year_request is private to this section.</li></ul>
|
|
<p class="commentary firstcommentary"><a id="SP9" class="paragraph-anchor"></a><b>§9. </b>We can't spin this out much longer, though... This is the actually
|
|
functional part of the program, and even so, it only calls a routine
|
|
in Foundation. (See <a href="../foundation-module/3-tm.html#SP3" class="internal">Time::easter</a>.)
|
|
</p>
|
|
|
|
<pre class="displayed-code all-displayed-code code-font">
|
|
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Main::report_on_years</span><button class="popup" onclick="togglePopup('usagePopup6')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup6">Usage of <span class="code-font"><span class="function-syntax">Main::report_on_years</span></span>:<br/><a href="S-rtd.html#SP2_1">§2.1</a></span></button><span class="plain-syntax">(</span><span class="reserved-syntax">text_stream</span><span class="plain-syntax"> *</span><span class="identifier-syntax">OUT</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">year_request</span><span class="plain-syntax"> *</span><span class="identifier-syntax">YR</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">LOOP_OVER</span><span class="plain-syntax">(</span><span class="identifier-syntax">YR</span><span class="plain-syntax">, </span><span class="reserved-syntax">year_request</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">d</span><span class="plain-syntax">, </span><span class="identifier-syntax">m</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><a href="../foundation-module/3-tm.html#SP3" class="function-link"><span class="function-syntax">Time::easter</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">YR</span><span class="plain-syntax">-></span><span class="element-syntax">year</span><span class="plain-syntax">, &</span><span class="identifier-syntax">d</span><span class="plain-syntax">, &</span><span class="identifier-syntax">m</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">american_mode</span><span class="plain-syntax">) { </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">x</span><span class="plain-syntax"> = </span><span class="identifier-syntax">d</span><span class="plain-syntax">; </span><span class="identifier-syntax">d</span><span class="plain-syntax"> = </span><span class="identifier-syntax">m</span><span class="plain-syntax">; </span><span class="identifier-syntax">m</span><span class="plain-syntax"> = </span><span class="identifier-syntax">x</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">verbose_mode</span><span class="plain-syntax">) </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"Easter in %d falls on %d/%d.\n"</span><span class="plain-syntax">, </span><span class="identifier-syntax">YR</span><span class="plain-syntax">-></span><span class="element-syntax">year</span><span class="plain-syntax">, </span><span class="identifier-syntax">d</span><span class="plain-syntax">, </span><span class="identifier-syntax">m</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"%d/%d/%d\n"</span><span class="plain-syntax">, </span><span class="identifier-syntax">d</span><span class="plain-syntax">, </span><span class="identifier-syntax">m</span><span class="plain-syntax">, </span><span class="identifier-syntax">YR</span><span class="plain-syntax">-></span><span class="element-syntax">year</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax">}</span>
|
|
</pre>
|
|
<!--End of weave-->
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|
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</main>
|
|
</body>
|
|
</html>
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