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<a href="./Home">MLton 20201002</a>
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<h1>SXML</h1>
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<div class="paragraph"><p><a href="SXML">SXML</a> is an <a href="IntermediateLanguage">IntermediateLanguage</a>, translated from <a href="XML">XML</a> by
<a href="Monomorphise">Monomorphise</a>, optimized by <a href="SXMLSimplify">SXMLSimplify</a>, and translated by
<a href="ClosureConvert">ClosureConvert</a> to <a href="SSA">SSA</a>.</p></div>
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<div class="sect1">
<h2 id="_description">Description</h2>
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<div class="paragraph"><p>SXML is a simply-typed version of <a href="XML">XML</a>.</p></div>
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<h2 id="_implementation">Implementation</h2>
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<div class="ulist"><ul>
<li>
<p>
<a href="https://github.com/MLton/mlton/blob/master/mlton/xml/sxml.sig"><span class="monospaced">sxml.sig</span></a>
</p>
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<p>
<a href="https://github.com/MLton/mlton/blob/master/mlton/xml/sxml.fun"><span class="monospaced">sxml.fun</span></a>
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<p>
<a href="https://github.com/MLton/mlton/blob/master/mlton/xml/sxml-tree.sig"><span class="monospaced">sxml-tree.sig</span></a>
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<h2 id="_type_checking">Type Checking</h2>
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<div class="paragraph"><p><a href="SXML">SXML</a> shares the type checker for <a href="XML">XML</a>.</p></div>
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<h2 id="_details_and_notes">Details and Notes</h2>
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<div class="paragraph"><p>There are only two differences between <a href="XML">XML</a> and <a href="SXML">SXML</a>.  First,
<a href="SXML">SXML</a> <span class="monospaced">val</span>, <span class="monospaced">fun</span>, and <span class="monospaced">datatype</span> declarations always have an
empty list of type variables.  Second, <a href="SXML">SXML</a> variable references
always have an empty list of type arguments.  Constructors uses can
only have a nonempty list of type arguments if the constructor is a
primitive.</p></div>
<div class="paragraph"><p>Although we could rely on the type system to enforce these constraints
by parameterizing the <a href="XML">XML</a> signature, <a href="StephenWeeks">StephenWeeks</a> did so in a
previous version of the compiler, and the software engineering gains
were not worth the effort.</p></div>
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