doc/guide/localhost/MLtonStructure

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  22 <a href="./Home">MLton 20180207</a>
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  26 <h1>MLtonStructure</h1>
  27 </div>
  28 <div id="content">
  29 <div id="preamble">
  30 <div class="sectionbody">
  31 <div class="paragraph"><p>The <span class="monospaced">MLton</span> structure contains a lot of functionality that is not
  32 available in the <a href="BasisLibrary">Basis Library</a>.  As a warning,
  33 please keep in mind that the <span class="monospaced">MLton</span> structure and its
  34 substructures do change from release to release of MLton.</p></div>
  35 <div class="listingblock">
  36 <div class="content"><div class="highlight"><pre><span class="k">structure</span><span class="w"> </span><span class="n">MLton</span><span class="p">:</span><span class="w"></span>
  37 <span class="w">   </span><span class="k">sig</span><span class="w"></span>
  38 <span class="w">      </span><span class="k">val</span><span class="w"> </span><span class="n">eq</span><span class="p">:</span><span class="w"> </span><span class="n">&#39;a</span><span class="w"> </span><span class="n">*</span><span class="w"> </span><span class="n">&#39;a</span><span class="w"> </span><span class="p">-&gt;</span><span class="w"> </span><span class="n">bool</span><span class="w"></span>
  39 <span class="w">      </span><span class="k">val</span><span class="w"> </span><span class="n">equal</span><span class="p">:</span><span class="w"> </span><span class="n">&#39;a</span><span class="w"> </span><span class="n">*</span><span class="w"> </span><span class="n">&#39;a</span><span class="w"> </span><span class="p">-&gt;</span><span class="w"> </span><span class="n">bool</span><span class="w"></span>
  40 <span class="w">      </span><span class="k">val</span><span class="w"> </span><span class="n">hash</span><span class="p">:</span><span class="w"> </span><span class="n">&#39;a</span><span class="w"> </span><span class="p">-&gt;</span><span class="w"> </span><span class="n">Word32</span><span class="p">.</span><span class="n">word</span><span class="w"></span>
  41 <span class="w">      </span><span class="k">val</span><span class="w"> </span><span class="n">isMLton</span><span class="p">:</span><span class="w"> </span><span class="n">bool</span><span class="w"></span>
  42 <span class="w">      </span><span class="k">val</span><span class="w"> </span><span class="n">share</span><span class="p">:</span><span class="w"> </span><span class="n">&#39;a</span><span class="w"> </span><span class="p">-&gt;</span><span class="w"> </span><span class="n">unit</span><span class="w"></span>
  43 <span class="w">      </span><span class="k">val</span><span class="w"> </span><span class="n">shareAll</span><span class="p">:</span><span class="w"> </span><span class="n">unit</span><span class="w"> </span><span class="p">-&gt;</span><span class="w"> </span><span class="n">unit</span><span class="w"></span>
  44 <span class="w">      </span><span class="k">val</span><span class="w"> </span><span class="n">size</span><span class="p">:</span><span class="w"> </span><span class="n">&#39;a</span><span class="w"> </span><span class="p">-&gt;</span><span class="w"> </span><span class="n">int</span><span class="w"></span>
  45
  46 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Array</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_ARRAY</span><span class="w"></span>
  47 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">BinIO</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_BIN_IO</span><span class="w"></span>
  48 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">CharArray</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_MONO_ARRAY</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">CharArray</span><span class="p">.</span><span class="n">array</span><span class="w"></span>
  49 <span class="w">                                            </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">elem</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">CharArray</span><span class="p">.</span><span class="n">elem</span><span class="w"></span>
  50 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">CharVector</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_MONO_VECTOR</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">CharVector</span><span class="p">.</span><span class="n">vector</span><span class="w"></span>
  51 <span class="w">                                              </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">elem</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">CharVector</span><span class="p">.</span><span class="n">elem</span><span class="w"></span>
  52 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Cont</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_CONT</span><span class="w"></span>
  53 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Exn</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_EXN</span><span class="w"></span>
  54 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Finalizable</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_FINALIZABLE</span><span class="w"></span>
  55 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">GC</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_GC</span><span class="w"></span>
  56 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">IntInf</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_INT_INF</span><span class="w"></span>
  57 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Itimer</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_ITIMER</span><span class="w"></span>
  58 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">LargeReal</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_REAL</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">LargeReal</span><span class="p">.</span><span class="n">real</span><span class="w"></span>
  59 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">LargeWord</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_WORD</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">LargeWord</span><span class="p">.</span><span class="n">word</span><span class="w"></span>
  60 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Platform</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_PLATFORM</span><span class="w"></span>
  61 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Pointer</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_POINTER</span><span class="w"></span>
  62 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">ProcEnv</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_PROC_ENV</span><span class="w"></span>
  63 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Process</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_PROCESS</span><span class="w"></span>
  64 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Profile</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_PROFILE</span><span class="w"></span>
  65 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Random</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_RANDOM</span><span class="w"></span>
  66 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Real</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_REAL</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Real</span><span class="p">.</span><span class="n">real</span><span class="w"></span>
  67 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Real32</span><span class="p">:</span><span class="w"> </span><span class="k">sig</span><span class="w"></span>
  68 <span class="w">                           </span><span class="k">include</span><span class="w"> </span><span class="n">MLTON_REAL</span><span class="w"></span>
  69 <span class="w">                           </span><span class="k">val</span><span class="w"> </span><span class="n">castFromWord</span><span class="p">:</span><span class="w"> </span><span class="n">Word32</span><span class="p">.</span><span class="n">word</span><span class="w"> </span><span class="p">-&gt;</span><span class="w"> </span><span class="n">t</span><span class="w"></span>
  70 <span class="w">                           </span><span class="k">val</span><span class="w"> </span><span class="n">castToWord</span><span class="p">:</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">-&gt;</span><span class="w"> </span><span class="n">Word32</span><span class="p">.</span><span class="n">word</span><span class="w"></span>
  71 <span class="w">                        </span><span class="k">end</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Real32</span><span class="p">.</span><span class="n">real</span><span class="w"></span>
  72 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Real64</span><span class="p">:</span><span class="w"> </span><span class="k">sig</span><span class="w"></span>
  73 <span class="w">                           </span><span class="k">include</span><span class="w"> </span><span class="n">MLTON_REAL</span><span class="w"></span>
  74 <span class="w">                           </span><span class="k">val</span><span class="w"> </span><span class="n">castFromWord</span><span class="p">:</span><span class="w"> </span><span class="n">Word64</span><span class="p">.</span><span class="n">word</span><span class="w"> </span><span class="p">-&gt;</span><span class="w"> </span><span class="n">t</span><span class="w"></span>
  75 <span class="w">                           </span><span class="k">val</span><span class="w"> </span><span class="n">castToWord</span><span class="p">:</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">-&gt;</span><span class="w"> </span><span class="n">Word64</span><span class="p">.</span><span class="n">word</span><span class="w"></span>
  76 <span class="w">                        </span><span class="k">end</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Real64</span><span class="p">.</span><span class="n">real</span><span class="w"></span>
  77 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Rlimit</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_RLIMIT</span><span class="w"></span>
  78 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Rusage</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_RUSAGE</span><span class="w"></span>
  79 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Signal</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_SIGNAL</span><span class="w"></span>
  80 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Syslog</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_SYSLOG</span><span class="w"></span>
  81 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">TextIO</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_TEXT_IO</span><span class="w"></span>
  82 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Thread</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_THREAD</span><span class="w"></span>
  83 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Vector</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_VECTOR</span><span class="w"></span>
  84 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Weak</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_WEAK</span><span class="w"></span>
  85 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Word</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_WORD</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Word</span><span class="p">.</span><span class="n">word</span><span class="w"></span>
  86 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Word8</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_WORD</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Word8</span><span class="p">.</span><span class="n">word</span><span class="w"></span>
  87 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Word16</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_WORD</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Word16</span><span class="p">.</span><span class="n">word</span><span class="w"></span>
  88 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Word32</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_WORD</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Word32</span><span class="p">.</span><span class="n">word</span><span class="w"></span>
  89 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Word64</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_WORD</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Word64</span><span class="p">.</span><span class="n">word</span><span class="w"></span>
  90 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Word8Array</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_MONO_ARRAY</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Word8Array</span><span class="p">.</span><span class="n">array</span><span class="w"></span>
  91 <span class="w">                                             </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">elem</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Word8Array</span><span class="p">.</span><span class="n">elem</span><span class="w"></span>
  92 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">Word8Vector</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_MONO_VECTOR</span><span class="w"> </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Word8Vector</span><span class="p">.</span><span class="n">vector</span><span class="w"></span>
  93 <span class="w">                                               </span><span class="k">where</span><span class="w"> </span><span class="k">type</span><span class="w"> </span><span class="n">elem</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">Word8Vector</span><span class="p">.</span><span class="n">elem</span><span class="w"></span>
  94 <span class="w">      </span><span class="k">structure</span><span class="w"> </span><span class="n">World</span><span class="p">:</span><span class="w"> </span><span class="n">MLTON_WORLD</span><span class="w"></span>
  95 <span class="w">   </span><span class="k">end</span><span class="w"></span>
  96 </pre></div></div></div>
  97 </div>
  98 </div>
  99 <div class="sect1">
 100 <h2 id="_substructures">Substructures</h2>
 101 <div class="sectionbody">
 102 <div class="ulist"><ul>
 103 <li>
 104 <p>
 105 <a href="MLtonArray">MLtonArray</a>
 106 </p>
 107 </li>
 108 <li>
 109 <p>
 110 <a href="MLtonBinIO">MLtonBinIO</a>
 111 </p>
 112 </li>
 113 <li>
 114 <p>
 115 <a href="MLtonCont">MLtonCont</a>
 116 </p>
 117 </li>
 118 <li>
 119 <p>
 120 <a href="MLtonExn">MLtonExn</a>
 121 </p>
 122 </li>
 123 <li>
 124 <p>
 125 <a href="MLtonFinalizable">MLtonFinalizable</a>
 126 </p>
 127 </li>
 128 <li>
 129 <p>
 130 <a href="MLtonGC">MLtonGC</a>
 131 </p>
 132 </li>
 133 <li>
 134 <p>
 135 <a href="MLtonIntInf">MLtonIntInf</a>
 136 </p>
 137 </li>
 138 <li>
 139 <p>
 140 <a href="MLtonIO">MLtonIO</a>
 141 </p>
 142 </li>
 143 <li>
 144 <p>
 145 <a href="MLtonItimer">MLtonItimer</a>
 146 </p>
 147 </li>
 148 <li>
 149 <p>
 150 <a href="MLtonMonoArray">MLtonMonoArray</a>
 151 </p>
 152 </li>
 153 <li>
 154 <p>
 155 <a href="MLtonMonoVector">MLtonMonoVector</a>
 156 </p>
 157 </li>
 158 <li>
 159 <p>
 160 <a href="MLtonPlatform">MLtonPlatform</a>
 161 </p>
 162 </li>
 163 <li>
 164 <p>
 165 <a href="MLtonPointer">MLtonPointer</a>
 166 </p>
 167 </li>
 168 <li>
 169 <p>
 170 <a href="MLtonProcEnv">MLtonProcEnv</a>
 171 </p>
 172 </li>
 173 <li>
 174 <p>
 175 <a href="MLtonProcess">MLtonProcess</a>
 176 </p>
 177 </li>
 178 <li>
 179 <p>
 180 <a href="MLtonRandom">MLtonRandom</a>
 181 </p>
 182 </li>
 183 <li>
 184 <p>
 185 <a href="MLtonReal">MLtonReal</a>
 186 </p>
 187 </li>
 188 <li>
 189 <p>
 190 <a href="MLtonRlimit">MLtonRlimit</a>
 191 </p>
 192 </li>
 193 <li>
 194 <p>
 195 <a href="MLtonRusage">MLtonRusage</a>
 196 </p>
 197 </li>
 198 <li>
 199 <p>
 200 <a href="MLtonSignal">MLtonSignal</a>
 201 </p>
 202 </li>
 203 <li>
 204 <p>
 205 <a href="MLtonSyslog">MLtonSyslog</a>
 206 </p>
 207 </li>
 208 <li>
 209 <p>
 210 <a href="MLtonTextIO">MLtonTextIO</a>
 211 </p>
 212 </li>
 213 <li>
 214 <p>
 215 <a href="MLtonThread">MLtonThread</a>
 216 </p>
 217 </li>
 218 <li>
 219 <p>
 220 <a href="MLtonVector">MLtonVector</a>
 221 </p>
 222 </li>
 223 <li>
 224 <p>
 225 <a href="MLtonWeak">MLtonWeak</a>
 226 </p>
 227 </li>
 228 <li>
 229 <p>
 230 <a href="MLtonWord">MLtonWord</a>
 231 </p>
 232 </li>
 233 <li>
 234 <p>
 235 <a href="MLtonWorld">MLtonWorld</a>
 236 </p>
 237 </li>
 238 </ul></div>
 239 </div>
 240 </div>
 241 <div class="sect1">
 242 <h2 id="_values">Values</h2>
 243 <div class="sectionbody">
 244 <div class="ulist"><ul>
 245 <li>
 246 <p>
 247 <span class="monospaced">eq (x, y)</span>
 248 </p>
 249 <div class="paragraph"><p>returns true if <span class="monospaced">x</span> and <span class="monospaced">y</span> are equal as pointers.  For simple types
 250 like <span class="monospaced">char</span>, <span class="monospaced">int</span>, and <span class="monospaced">word</span>, this is the same as equals.  For
 251 arrays, datatypes, strings, tuples, and vectors, this is a simple
 252 pointer equality.  The semantics is a bit murky.</p></div>
 253 </li>
 254 <li>
 255 <p>
 256 <span class="monospaced">equal (x, y)</span>
 257 </p>
 258 <div class="paragraph"><p>returns true if <span class="monospaced">x</span> and <span class="monospaced">y</span> are structurally equal.  For equality
 259 types, this is the same as <a href="PolymorphicEquality">PolymorphicEquality</a>.  For other types,
 260 it is a conservative approximation of equivalence.</p></div>
 261 </li>
 262 <li>
 263 <p>
 264 <span class="monospaced">hash x</span>
 265 </p>
 266 <div class="paragraph"><p>returns a structural hash of <span class="monospaced">x</span>.  The hash function is consistent
 267 between execution of the same program, but may not be consistent
 268 between different programs.</p></div>
 269 </li>
 270 <li>
 271 <p>
 272 <span class="monospaced">isMLton</span>
 273 </p>
 274 <div class="paragraph"><p>is always <span class="monospaced">true</span> in a MLton implementation, and is always <span class="monospaced">false</span> in a
 275 stub implementation.</p></div>
 276 </li>
 277 <li>
 278 <p>
 279 <span class="monospaced">share x</span>
 280 </p>
 281 <div class="paragraph"><p>maximizes sharing in the heap for the object graph reachable from <span class="monospaced">x</span>.</p></div>
 282 </li>
 283 <li>
 284 <p>
 285 <span class="monospaced">shareAll ()</span>
 286 </p>
 287 <div class="paragraph"><p>maximizes sharing in the heap by sharing space for equivalent
 288 immutable objects.  A call to <span class="monospaced">shareAll</span> performs a major garbage
 289 collection, and takes time proportional to the size of the heap.</p></div>
 290 </li>
 291 <li>
 292 <p>
 293 <span class="monospaced">size x</span>
 294 </p>
 295 <div class="paragraph"><p>returns the amount of heap space (in bytes) taken by the value of <span class="monospaced">x</span>,
 296 including all objects reachable from <span class="monospaced">x</span> by following pointers.  It
 297 takes time proportional to the size of <span class="monospaced">x</span>.  See below for an example.</p></div>
 298 </li>
 299 </ul></div>
 300 </div>
 301 </div>
 302 <div class="sect1">
 303 <h2 id="_a_id_size_a_example_of_span_class_monospaced_mlton_size_span"><a id="size"></a>Example of <span class="monospaced">MLton.size</span></h2>
 304 <div class="sectionbody">
 305 <div class="paragraph"><p>This example, <span class="monospaced">size.sml</span>, demonstrates the application of <span class="monospaced">MLton.size</span>
 306 to many different kinds of objects.</p></div>
 307 <div class="listingblock">
 308 <div class="content"><div class="highlight"><pre><span class="k">fun</span><span class="w"> </span><span class="n">&#39;a</span><span class="w"> </span><span class="n">printSize</span><span class="w"> </span><span class="p">(</span><span class="n">name</span><span class="p">:</span><span class="w"> </span><span class="n">string</span><span class="p">,</span><span class="w"> </span><span class="n">value</span><span class="p">:</span><span class="w"> </span><span class="n">&#39;a</span><span class="p">):</span><span class="w"> </span><span class="n">unit</span><span class="p">=</span><span class="w"></span>
 309 <span class="w">   </span><span class="p">(</span><span class="n">print</span><span class="w"> </span><span class="s">&quot;The size of &quot;</span><span class="w"></span>
 310 <span class="w">    </span><span class="p">;</span><span class="w"> </span><span class="n">print</span><span class="w"> </span><span class="n">name</span><span class="w"></span>
 311 <span class="w">    </span><span class="p">;</span><span class="w"> </span><span class="n">print</span><span class="w"> </span><span class="s">&quot; is &quot;</span><span class="w"></span>
 312 <span class="w">    </span><span class="p">;</span><span class="w"> </span><span class="n">print</span><span class="w"> </span><span class="p">(</span><span class="n">Int</span><span class="p">.</span><span class="n">toString</span><span class="w"> </span><span class="p">(</span><span class="n">MLton</span><span class="p">.</span><span class="n">size</span><span class="w"> </span><span class="n">value</span><span class="p">))</span><span class="w"></span>
 313 <span class="w">    </span><span class="p">;</span><span class="w"> </span><span class="n">print</span><span class="w"> </span><span class="s">&quot; bytes.</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">)</span><span class="w"></span>
 314
 315 <span class="k">val</span><span class="w"> </span><span class="n">l</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="p">[</span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="mi">2</span><span class="p">,</span><span class="w"> </span><span class="mi">3</span><span class="p">,</span><span class="w"> </span><span class="mi">4</span><span class="p">]</span><span class="w"></span>
 316
 317 <span class="k">val</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=</span><span class="w"></span>
 318 <span class="w">   </span><span class="p">(</span><span class="w"></span>
 319 <span class="w">    </span><span class="n">printSize</span><span class="w"> </span><span class="p">(</span><span class="s">&quot;an int list of length 4&quot;</span><span class="p">,</span><span class="w"> </span><span class="n">l</span><span class="p">)</span><span class="w"></span>
 320 <span class="w">    </span><span class="p">;</span><span class="w"> </span><span class="n">printSize</span><span class="w"> </span><span class="p">(</span><span class="s">&quot;a string of length 10&quot;</span><span class="p">,</span><span class="w"> </span><span class="s">&quot;0123456789&quot;</span><span class="p">)</span><span class="w"></span>
 321 <span class="w">    </span><span class="p">;</span><span class="w"> </span><span class="n">printSize</span><span class="w"> </span><span class="p">(</span><span class="s">&quot;an int array of length 10&quot;</span><span class="p">,</span><span class="w"> </span><span class="n">Array</span><span class="p">.</span><span class="n">tabulate</span><span class="w"> </span><span class="p">(</span><span class="mi">10</span><span class="p">,</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="mi">0</span><span class="p">))</span><span class="w"></span>
 322 <span class="w">    </span><span class="p">;</span><span class="w"> </span><span class="n">printSize</span><span class="w"> </span><span class="p">(</span><span class="s">&quot;a double array of length 10&quot;</span><span class="p">,</span><span class="w"></span>
 323 <span class="w">                 </span><span class="n">Array</span><span class="p">.</span><span class="n">tabulate</span><span class="w"> </span><span class="p">(</span><span class="mi">10</span><span class="p">,</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="mf">0.0</span><span class="p">))</span><span class="w"></span>
 324 <span class="w">    </span><span class="p">;</span><span class="w"> </span><span class="n">printSize</span><span class="w"> </span><span class="p">(</span><span class="s">&quot;an array of length 10 of 2-ples of ints&quot;</span><span class="p">,</span><span class="w"></span>
 325 <span class="w">                 </span><span class="n">Array</span><span class="p">.</span><span class="n">tabulate</span><span class="w"> </span><span class="p">(</span><span class="mi">10</span><span class="p">,</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="p">,</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="n">+</span><span class="w"> </span><span class="mi">1</span><span class="p">)))</span><span class="w"></span>
 326 <span class="w">    </span><span class="p">;</span><span class="w"> </span><span class="n">printSize</span><span class="w"> </span><span class="p">(</span><span class="s">&quot;a useless function&quot;</span><span class="p">,</span><span class="w"> </span><span class="k">fn</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="mi">13</span><span class="p">)</span><span class="w"></span>
 327 <span class="w">    </span><span class="p">)</span><span class="w"></span>
 328
 329 <span class="cm">(* This is here so that the list is &quot;useful&quot;.</span>
 330 <span class="cm"> * If it were removed, then the optimizer (remove-unused-constructors)</span>
 331 <span class="cm"> * would remove l entirely.</span>
 332 <span class="cm"> *)</span><span class="w"></span>
 333 <span class="k">val</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="mi">10</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">foldl</span><span class="w"> </span><span class="p">(</span><span class="k">op</span><span class="w"> </span><span class="n">+</span><span class="p">)</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="n">l</span><span class="w"></span>
 334 <span class="w">           </span><span class="k">then</span><span class="w"> </span><span class="p">()</span><span class="w"></span>
 335 <span class="w">        </span><span class="k">else</span><span class="w"> </span><span class="k">raise</span><span class="w"> </span><span class="n">Fail</span><span class="w"> </span><span class="s">&quot;bug&quot;</span><span class="w"></span>
 336
 337 <span class="k">local</span><span class="w"></span>
 338 <span class="w">   </span><span class="k">open</span><span class="w"> </span><span class="n">MLton</span><span class="p">.</span><span class="n">Cont</span><span class="w"></span>
 339 <span class="k">in</span><span class="w"></span>
 340 <span class="w">   </span><span class="k">val</span><span class="w"> </span><span class="n">rc</span><span class="p">:</span><span class="w"> </span><span class="n">int</span><span class="w"> </span><span class="n">option</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="n">option</span><span class="w"> </span><span class="n">ref</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">ref</span><span class="w"> </span><span class="n">NONE</span><span class="w"></span>
 341 <span class="w">   </span><span class="k">val</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=</span><span class="w"></span>
 342 <span class="w">      </span><span class="k">case</span><span class="w"> </span><span class="n">callcc</span><span class="w"> </span><span class="p">(</span><span class="k">fn</span><span class="w"> </span><span class="n">k</span><span class="p">:</span><span class="w"> </span><span class="n">int</span><span class="w"> </span><span class="n">option</span><span class="w"> </span><span class="n">t</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="p">(</span><span class="n">rc</span><span class="w"> </span><span class="n">:=</span><span class="w"> </span><span class="n">SOME</span><span class="w"> </span><span class="n">k</span><span class="p">;</span><span class="w"> </span><span class="n">throw</span><span class="w"> </span><span class="p">(</span><span class="n">k</span><span class="p">,</span><span class="w"> </span><span class="n">NONE</span><span class="p">)))</span><span class="w"> </span><span class="k">of</span><span class="w"></span>
 343 <span class="w">         </span><span class="n">NONE</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="p">()</span><span class="w"></span>
 344 <span class="w">       </span><span class="p">|</span><span class="w"> </span><span class="n">SOME</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="n">print</span><span class="w"> </span><span class="p">(</span><span class="n">concat</span><span class="w"> </span><span class="p">[</span><span class="n">Int</span><span class="p">.</span><span class="n">toString</span><span class="w"> </span><span class="n">i</span><span class="p">,</span><span class="w"> </span><span class="s">&quot;</span><span class="se">\n</span><span class="s">&quot;</span><span class="p">])</span><span class="w"></span>
 345 <span class="k">end</span><span class="w"></span>
 346
 347 <span class="k">val</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="n">printSize</span><span class="w"> </span><span class="p">(</span><span class="s">&quot;a continuation option ref&quot;</span><span class="p">,</span><span class="w"> </span><span class="n">rc</span><span class="p">)</span><span class="w"></span>
 348
 349 <span class="k">val</span><span class="w"> </span><span class="p">_</span><span class="w"> </span><span class="p">=</span><span class="w"></span>
 350 <span class="w">   </span><span class="k">case</span><span class="w"> </span><span class="n">!rc</span><span class="w"> </span><span class="k">of</span><span class="w"></span>
 351 <span class="w">      </span><span class="n">NONE</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="p">()</span><span class="w"></span>
 352 <span class="w">    </span><span class="p">|</span><span class="w"> </span><span class="n">SOME</span><span class="w"> </span><span class="n">k</span><span class="w"> </span><span class="p">=&gt;</span><span class="w"> </span><span class="p">(</span><span class="n">rc</span><span class="w"> </span><span class="n">:=</span><span class="w"> </span><span class="n">NONE</span><span class="p">;</span><span class="w"> </span><span class="n">MLton</span><span class="p">.</span><span class="n">Cont</span><span class="p">.</span><span class="n">throw</span><span class="w"> </span><span class="p">(</span><span class="n">k</span><span class="p">,</span><span class="w"> </span><span class="n">SOME</span><span class="w"> </span><span class="mi">13</span><span class="p">))</span><span class="w"></span>
 353 </pre></div></div></div>
 354 <div class="paragraph"><p>Compile and run as usual.</p></div>
 355 <div class="listingblock">
 356 <div class="content monospaced">
 357 <pre>% mlton size.sml
 358 % ./size
 359 The size of an int list of length 4 is 48 bytes.
 360 The size of a string of length 10 is 24 bytes.
 361 The size of an int array of length 10 is 52 bytes.
 362 The size of a double array of length 10 is 92 bytes.
 363 The size of an array of length 10 of 2-ples of ints is 92 bytes.
 364 The size of a useless function is 0 bytes.
 365 The size of a continuation option ref is 4544 bytes.
 366 13
 367 The size of a continuation option ref is 8 bytes.</pre>
 368 </div></div>
 369 <div class="paragraph"><p>Note that sizes are dependent upon the target platform and compiler
 370 optimizations.</p></div>
 371 </div>
 372 </div>
 373 </div>
 374 <div id="footnotes"><hr></div>
 375 <div id="footer">
 376 <div id="footer-text">
 377 </div>
 378 <div id="footer-badges">
 379 </div>
 380 </div>
 381 </body>
 382 </html>