<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta name="robots" content="index,nofollow"> <title>LambdaFree - MLton Standard ML Compiler (SML Compiler)</title> <link rel="stylesheet" type="text/css" charset="iso-8859-1" media="all" href="common.css"> <link rel="stylesheet" type="text/css" charset="iso-8859-1" media="screen" href="screen.css"> <link rel="stylesheet" type="text/css" charset="iso-8859-1" media="print" href="print.css"> <link rel="Start" href="Home"> </head> <body lang="en" dir="ltr"> <script src="http://www.google-analytics.com/urchin.js" type="text/javascript"> </script> <script type="text/javascript"> _uacct = "UA-833377-1"; urchinTracker(); </script> <table bgcolor = lightblue cellspacing = 0 style = "border: 0px;" width = 100%> <tr> <td style = " border: 0px; color: darkblue; font-size: 150%; text-align: left;"> <a class = mltona href="Home">MLton MLTONWIKIVERSION</a> <td style = " border: 0px; font-size: 150%; text-align: center; width: 50%;"> LambdaFree <td style = " border: 0px; text-align: right;"> <table cellspacing = 0 style = "border: 0px"> <tr style = "vertical-align: middle;"> </table> <tr style = "background-color: white;"> <td colspan = 3 style = " border: 0px; font-size:70%; text-align: right;"> <a href = "Home">Home</a> <a href = "TitleIndex">Index</a> </table> <div id="content" lang="en" dir="ltr"> LambdaFree is an analysis pass for the <a href="SXML">SXML</a> <a href="IntermediateLanguage">IntermediateLanguage</a>, invoked from <a href="ClosureConvert">ClosureConvert</a>. <h2 id="head-55f8ebc805e65b5b71ddafdae390e3be2bcd69af">Description</h2> <p> This pass descends the entire <a href="SXML">SXML</a> program and attaches a property to each <tt>Lambda</tt> <tt>PrimExp.t</tt> in the program. Then, you can use <tt>lambdaFree</tt> and <tt>lambdaRec</tt> to get free variables of that <tt>Lambda</tt>. </p> <h2 id="head-8781d615fd77be9578225c40ac67b9471394cced">Implementation</h2> <a href = "http://mlton.org/cgi-bin/viewsvn.cgi/mlton/tags/on-MLTONWIKIVERSION-release/mlton/closure-convert/lambda-free.sig?view=markup"><img src="moin-www.png" alt="[WWW]" height="11" width="11">lambda-free.sig</a> <a href = "http://mlton.org/cgi-bin/viewsvn.cgi/mlton/tags/on-MLTONWIKIVERSION-release/mlton/closure-convert/lambda-free.fun?view=markup"><img src="moin-www.png" alt="[WWW]" height="11" width="11">lambda-free.fun</a> <h2 id="head-35ec00231a68203708e39f0e2cc10b50c6bf62de">Details and Notes</h2> <p> For <tt>Lambda</tt>s bound in a <tt>Fun</tt> dec, <tt>lambdaFree</tt> gives the union of the frees of the entire group of mutually recursive functions. Hence, <tt>lambdaFree</tt> for every <tt>Lambda</tt> in a single <tt>Fun</tt> dec is the same. Furthermore, for a <tt>Lambda</tt> bound in a <tt>Fun</tt> dec, <tt>lambdaRec</tt> gives the list of other functions bound in the same dec defining that <tt>Lambda</tt>. For example: <pre>val rec f = fn x => ... y ... g ... f ... and g = fn z => ... f ... w ... </pre> <pre> * lambdaFree(fn x =>) = [y, w] * lambdaFree(fn z =>) = [y, w] * lambdaRec(fn x =>) = [g, f] * lambdaRec(fn z =>) = [f] </pre> </p> </div> <p> <hr> Last edited on 2006-11-02 17:37:38 by <span title="76.16.241.4"><a href="MatthewFluet">MatthewFluet</a></span>. </body></html>