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<pre class=code>
<B><FONT COLOR="#0000FF">signature</FONT></B> MLTON_WORLD =
<B><FONT COLOR="#0000FF">sig</FONT></B>
<B><FONT COLOR="#A020F0">datatype</FONT></B><B><FONT COLOR="#228B22"> status </FONT></B>=<B><FONT COLOR="#228B22"> <FONT COLOR="#B8860B">Clone</FONT> </FONT></B>|<B><FONT COLOR="#228B22"> <FONT COLOR="#B8860B">Original</FONT>
</FONT></B><B><FONT COLOR="#A020F0">val</FONT></B> load: string -> 'a
<B><FONT COLOR="#A020F0">val</FONT></B> save: string -> status
<B><FONT COLOR="#A020F0">val</FONT></B> saveThread: string * Thread.Runnable.t -> unit
<B><FONT COLOR="#0000FF">end</FONT></B>
</PRE>
<p>
</p>
<ul>
<li>
<p>
<tt>datatype status</tt> <br>
specifies whether a world is original or restarted (a clone).
</p>
</li>
<li class="gap">
<p>
<tt>load f</tt> <br>
loads the saved computation from file <tt>f</tt>.
</p>
</li>
<li class="gap">
<p>
<tt>save f</tt> <br>
saves the entire state of the computation to the file <tt>f</tt>. The computation can then be restarted at a later time using <tt>World.load</tt> or the <tt>load-world</tt> <a href="RunTimeOptions">runtime option</a>. The call to <tt>save</tt> in the original computation returns <tt>Original</tt> and the call in the restarted world returns <tt>Clone</tt>.
</p>
</li>
<li class="gap">
<p>
<tt>saveThread (f, rt)</tt> <br>
saves the entire state of the computation to the file <tt>f</tt> that will resume with thread <tt>rt</tt> upon restart.
</p>
</li>
</ul>
<h2 id="head-0f01ed56a1e32a05e5ef96e4d779f34784af9a96">Example</h2>
<p>
Suppose that <tt>save-world.sml</tt> contains the following.
<pre class=code>
<B><FONT COLOR="#0000FF">open</FONT></B> MLton.World
<B><FONT COLOR="#A020F0">val</FONT></B> _ =
<B><FONT COLOR="#A020F0">case</FONT></B> save <B><FONT COLOR="#BC8F8F">"world"</FONT></B> <B><FONT COLOR="#A020F0">of</FONT></B>
Original => print <B><FONT COLOR="#BC8F8F">"I am the original\n"</FONT></B>
| Clone => print <B><FONT COLOR="#BC8F8F">"I am the clone\n"</FONT></B>
</PRE>
</p>
<p>
Then, if we compile <tt>save-world.sml</tt> and run it, the <tt>Original</tt> branch will execute, and a file named <tt>world</tt> will be created.
<pre>% mlton save-world.sml
% save-world
I am the original
</pre>
</p>
<p>
We can then load <tt>world</tt> using the <tt>load-world</tt> <a href="RunTimeOptions">run time option</a>.
</p>
<pre>% save-world @MLton load-world world --
I am the clone
</pre></div>
<p>
<hr>
Last edited on 2007-08-23 03:46:03 by <span title="c-71-57-91-146.hsd1.il.comcast.net"><a href="MatthewFluet">MatthewFluet</a></span>.
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