doc/guide/localhost/Identifier

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  26 <h1>Identifier</h1>
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  31 <div class="paragraph"><p>In <a href="StandardML">Standard ML</a>, there are syntactically two kinds of
  32 identifiers.</p></div>
  33 <div class="ulist"><ul>
  34 <li>
  35 <p>
  36 Alphanumeric: starts with a letter or prime (<span class="monospaced">'</span>) and is followed by letters, digits, primes and underbars (<span class="monospaced">_</span>).
  37 </p>
  38 <div class="paragraph"><p>Examples: <span class="monospaced">abc</span>, <span class="monospaced">ABC123</span>, <span class="monospaced">Abc_123</span>, <span class="monospaced">'a</span>.</p></div>
  39 </li>
  40 <li>
  41 <p>
  42 Symbolic: a sequence of the following
  43 </p>
  44 <div class="listingblock">
  45 <div class="content monospaced">
  46 <pre> ! % &amp; $ # + - / : &lt; = &gt; ? @ | ~ ` ^ | *</pre>
  47 </div></div>
  48 <div class="paragraph"><p>Examples: <span class="monospaced">+=</span>, <span class="monospaced">&lt;=</span>, <span class="monospaced">&gt;&gt;</span>, <span class="monospaced">$</span>.</p></div>
  49 </li>
  50 </ul></div>
  51 <div class="paragraph"><p>With the exception of <span class="monospaced">=</span>, reserved words can not be identifiers.</p></div>
  52 <div class="paragraph"><p>There are a number of different classes of identifiers, some of which
  53 have additional syntactic rules.</p></div>
  54 <div class="ulist"><ul>
  55 <li>
  56 <p>
  57 Identifiers not starting with a prime.
  58 </p>
  59 <div class="ulist"><ul>
  60 <li>
  61 <p>
  62 value identifier (includes variables and constructors)
  63 </p>
  64 </li>
  65 <li>
  66 <p>
  67 type constructor
  68 </p>
  69 </li>
  70 <li>
  71 <p>
  72 structure identifier
  73 </p>
  74 </li>
  75 <li>
  76 <p>
  77 signature identifier
  78 </p>
  79 </li>
  80 <li>
  81 <p>
  82 functor identifier
  83 </p>
  84 </li>
  85 </ul></div>
  86 </li>
  87 <li>
  88 <p>
  89 Identifiers starting with a prime.
  90 </p>
  91 <div class="ulist"><ul>
  92 <li>
  93 <p>
  94 type variable
  95 </p>
  96 </li>
  97 </ul></div>
  98 </li>
  99 <li>
 100 <p>
 101 Identifiers not starting with a prime and numeric labels (<span class="monospaced">1</span>, <span class="monospaced">2</span>, &#8230;).
 102 </p>
 103 <div class="ulist"><ul>
 104 <li>
 105 <p>
 106 record label
 107 </p>
 108 </li>
 109 </ul></div>
 110 </li>
 111 </ul></div>
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