all repos — h3rald @ 2e83d5668f040221d07b71f73f63143db2608739

The sources of https://h3rald.com

content/glyph/book/text_editing/macro_composition.html

 1
 2
 3
 4
 5
 6
 7
 8
 9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
<!DOCTYPE html> 
<html lang="en"> 
	<head> 
    <title>Macro Composition - Glyph</title> 
		<link href='http://fonts.googleapis.com/css?family=Crimson+Text:400,400italic,600,600italic,700,700italic' rel='stylesheet' type='text/css'>
		
		
		
		<meta charset="utf-8" />
		<meta name="author" content="Fabio Cevasco" />
		<meta name="copyright" content="Fabio Cevasco" />
		<meta name="robots" content="all, follow" />
		<meta name="Revisit-After" content="2 Days" />
		<meta name="language" content="en" />
		<meta name="target_country" content="en-us" />
		<meta name="country" content="United States" />
                <meta name="readability-verification" content="XmaVzRjmcFL5Bb2Fu9TZVdDKzhA3apQdxexTB2rK"/>
		<meta name="description" content="H3RALD - Fabio Cevasco's Web Site" />
		
		<meta name="keywords" content="h3rald, fabio cevasco, glyph" />
		<link rel="shortcut icon" href="/favicon.png" type="image/png" /> 
		<meta content="44.388041;9.073248" name="ICBM" />

		<link rel="stylesheet" type="text/css" href="/styles/html5reset.css" />
		<link rel="stylesheet" type="text/css" href="/styles/style.css" />

    <script src="http://www.google.com/jsapi?key=ABQIAAAAr6RY1Z6dchG_sX9WDLSy3xRlq2n1sm52B5HDRR5tm6o8XM18FhR56xHNNH6CsX86uN5VoTrglpyOyQ" type="text/javascript"></script>
		<script src="/js/sevenup.js" type="text/javascript"></script>
		<script src="/js/sevenup_black.js" type="text/javascript"></script>
		<script type="text/javascript">google.load("jquery", "1");</script>
		<script src="/js/jquery-timeago.js" type="text/javascript"></script>
		<script src="/js/jquery-easing.js" type="text/javascript"></script>
		<script src="/js/jquery-fancybox.js" type="text/javascript"></script>
		<script src="/js/date.js" type="text/javascript"></script>
		<script src="/js/feeds.js" type="text/javascript"></script>
		<script src="/js/hyphenator.js" type="text/javascript"></script>
		<script src="/js/init.js" type="text/javascript"></script>
		<script src="/js/search.js" type="text/javascript"></script>
	</head>
	<body>
		<section id="container">
			
				<header class="page">
	<nav class="home-link">
		<a href="/">
			<img src="/images/h3rald_small.png" alt="H3RALD" class="default"/>
			<![if !IE]>
			<img src="/images/h3rald_hover_small.png" alt="H3RALD" class="hover"/>
			<![endif]>
		</a>
	</nav>
	
	<nav class="section">
		/<a href="/glyph/" rel="glyph">GLYPH</a>
	</nav>
	
</header>
				<article class="page glyph-book">
					<header>
	<hgroup>
		<h1>Macro Composition</h1> 
		<h2>Glyph</h2>
	</hgroup>
  </header>
					<section id="body-text" class="hyphenate glyph-book">

							<nav class="navigation"><a href="/glyph/book/text_editing/attribute_intro.html">Macro attributes</a> | <a href="/glyph/book/index.html">Contents</a> | <a href="/glyph/book/text_editing/esc_quot.html">Escaping and Quoting</a></nav>
							<p>Glyph macros can be <em>composed</em> with other using the <code>/</code> character. Macro composition can be used instead of nesting, provided that macro containers (also called <em>dispatchers</em> in certain situations) take only one parameter and no attributes.</p>
<p>For example, the following code:</p>
<div class="CodeRay">
  <div class="code"><pre><span class="line-numbers"><a href="#n1" name="n1">1</a></span>?[
<span class="line-numbers"><a href="#n2" name="n2">2</a></span>  not[output?[pdf]]|
<span class="line-numbers"><a href="#n3" name="n3">3</a></span>  ...
<span class="line-numbers"><a href="#n4" name="n4">4</a></span>]
</pre></div>
</div>


<p>Can be written like this:</p>

<div class="CodeRay">
  <div class="code"><pre><span class="line-numbers"><a href="#n1" name="n1">1</a></span>?[
<span class="line-numbers"><a href="#n2" name="n2">2</a></span>  not/output?[pdf]|
<span class="line-numbers"><a href="#n3" name="n3">3</a></span>  ...
<span class="line-numbers"><a href="#n4" name="n4">4</a></span>]
</pre></div>
</div>


<p>In this case, the <a href="/glyph/book/macros/macros_core.html#m_not"><code>not</code></a> macro was composed with the <a href="/glyph/book/macros/macros_core.html#m_output_"><code>output?</code></a> macro, thus removing one level of nesting.</p>
<p>Composition can be useful to simplify complex Glyph macro constructs, but also for <em>macro dispatching</em>. Currently, Glyph supports two <em>dispatchers</em>:</p>
<ul>
	<li>The <a href="/glyph/book/macros/macros_core.html#m_s"><code>s</code></a> macro, used to call almost any method of the Ruby String class.</li>
	<li>The <a href="/glyph/book/macros/macros_core.html#m_xml"><code>xml</code></a> macro, used to render raw <span class="caps">XML</span> tags.</li>
</ul>
							<nav class="navigation"><a href="/glyph/book/text_editing/attribute_intro.html">Macro attributes</a> | <a href="/glyph/book/index.html">Contents</a> | <a href="/glyph/book/text_editing/esc_quot.html">Escaping and Quoting</a></nav>
										<nav id="sharing-buttons">
<a href="http://twitter.com/share" class="twitter-share-button" data-count="horizontal" data-via="h3rald">Tweet</a>
<script type="text/javascript" src="http://platform.twitter.com/widgets.js"></script>
<g:plusone size="medium"></g:plusone>
<script type="text/javascript">
  (function() {
    var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true;
    po.src = 'https://apis.google.com/js/plusone.js';
    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s);
  })();
</script>
</nav>
					</section>
				</article>
					
			
			<footer>
				<section class="ads">
					<script type="text/javascript"><!--
						google_ad_client = "pub-2871497824158668";
						/* 728x90, created 9/10/10 */
						google_ad_slot = "3963343166";
						google_ad_width = 728;
						google_ad_height = 90;
						//-->
					</script>
					<script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
					</script>
				</section>
				<section>
					<nav>
						<a href="/about/">ABOUT</a>|<a href="/contact/">CONTACT</a>
					</nav>
					<p>H3RALD Web Site v8.1.2 &copy; 2004 &mdash; 2011 <em>Fabio Cevasco</em></p>
				</section>
			</footer>
		</section><!-- #container end -->
		
		
 <!-- Start Google Analytics --> 
 <script type="text/javascript">
  var _gaq = _gaq || [];
  _gaq.push(['_setAccount', 'UA-18587377-1']);
  _gaq.push(['_trackPageview']);

  (function() {
    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
  })();
 </script> 
 <!-- End Google Analytics --> 
 <!-- Start of StatCounter Code --> 
  <script type="text/javascript"> 
	var sc_project=6193656; 
	var sc_invisible=1; 
	var sc_security="57f7ee2a"; 
	</script> 
	<script type="text/javascript" src="http://www.statcounter.com/counter/counter_xhtml.js"></script> 
	<!-- End of StatCounter Code --> 
	</body>
</html>