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<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"/><title>15.3 Scripting Evaluation and Using load</title><link rel="stylesheet" type="text/css" href="../scribble.css" title="default"/><link rel="stylesheet" type="text/css" href="../racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-style.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../manual-racket.css" title="default"/><link rel="stylesheet" type="text/css" href="../doc-site.css" title="default"/><script type="text/javascript" src="../scribble-common.js"></script><script type="text/javascript" src="../manual-racket.js"></script><script type="text/javascript" src="../manual-racket.js"></script><script type="text/javascript" src="../doc-site.js"></script><script type="text/javascript" src="../local-redirect/local-redirect.js"></script><script type="text/javascript" src="../local-redirect/local-user-redirect.js"></script><!--[if IE 6]><style type="text/css">.SIEHidden { overflow: hidden; }</style><![endif]--></head><body id="doc-racket-lang-org"><div class="tocset"><div class="tocview"><div class="tocviewlist tocviewlisttopspace"><div class="tocviewtitle"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,"tocview_0");">►</a></td><td></td><td><a href="index.html" class="tocviewlink" data-pltdoc="x"><span style="font-weight: bold">The Racket Guide</span></a></td></tr></table></div><div class="tocviewsublisttop" style="display: none;" id="tocview_0"><table cellspacing="0" cellpadding="0"><tr><td align="right">1 </td><td><a href="intro.html" class="tocviewlink" data-pltdoc="x">Welcome to Racket</a></td></tr><tr><td align="right">2 </td><td><a href="to-scheme.html" class="tocviewlink" data-pltdoc="x">Racket Essentials</a></td></tr><tr><td align="right">3 </td><td><a href="datatypes.html" class="tocviewlink" data-pltdoc="x">Built-<wbr></wbr>In Datatypes</a></td></tr><tr><td align="right">4 </td><td><a href="scheme-forms.html" class="tocviewlink" data-pltdoc="x">Expressions and Definitions</a></td></tr><tr><td align="right">5 </td><td><a href="define-struct.html" class="tocviewlink" data-pltdoc="x">Programmer-<wbr></wbr>Defined Datatypes</a></td></tr><tr><td align="right">6 </td><td><a href="modules.html" class="tocviewlink" data-pltdoc="x">Modules</a></td></tr><tr><td align="right">7 </td><td><a href="contracts.html" class="tocviewlink" data-pltdoc="x">Contracts</a></td></tr><tr><td align="right">8 </td><td><a href="i_o.html" class="tocviewlink" data-pltdoc="x">Input and Output</a></td></tr><tr><td align="right">9 </td><td><a href="regexp.html" class="tocviewlink" data-pltdoc="x">Regular Expressions</a></td></tr><tr><td align="right">10 </td><td><a href="control.html" class="tocviewlink" data-pltdoc="x">Exceptions and Control</a></td></tr><tr><td align="right">11 </td><td><a href="for.html" class="tocviewlink" data-pltdoc="x">Iterations and Comprehensions</a></td></tr><tr><td align="right">12 </td><td><a href="match.html" class="tocviewlink" data-pltdoc="x">Pattern Matching</a></td></tr><tr><td align="right">13 </td><td><a href="classes.html" class="tocviewlink" data-pltdoc="x">Classes and Objects</a></td></tr><tr><td align="right">14 </td><td><a href="units.html" class="tocviewlink" data-pltdoc="x">Units (Components)</a></td></tr><tr><td align="right">15 </td><td><a href="reflection.html" class="tocviewselflink" data-pltdoc="x">Reflection and Dynamic Evaluation</a></td></tr><tr><td align="right">16 </td><td><a href="macros.html" class="tocviewlink" data-pltdoc="x">Macros</a></td></tr><tr><td align="right">17 </td><td><a href="languages.html" class="tocviewlink" data-pltdoc="x">Creating Languages</a></td></tr><tr><td align="right">18 </td><td><a href="concurrency.html" class="tocviewlink" data-pltdoc="x">Concurrency and Synchronization</a></td></tr><tr><td align="right">19 </td><td><a href="performance.html" class="tocviewlink" data-pltdoc="x">Performance</a></td></tr><tr><td align="right">20 </td><td><a href="parallelism.html" class="tocviewlink" data-pltdoc="x">Parallelism</a></td></tr><tr><td align="right">21 </td><td><a href="running.html" class="tocviewlink" data-pltdoc="x">Running and Creating Executables</a></td></tr><tr><td align="right">22 </td><td><a href="More_Libraries.html" class="tocviewlink" data-pltdoc="x">More Libraries</a></td></tr><tr><td align="right">23 </td><td><a href="dialects.html" class="tocviewlink" data-pltdoc="x">Dialects of Racket and Scheme</a></td></tr><tr><td align="right">24 </td><td><a href="other-editors.html" class="tocviewlink" data-pltdoc="x">Command-<wbr></wbr>Line Tools and Your Editor of Choice</a></td></tr><tr><td align="right"></td><td><a href="doc-bibliography.html" class="tocviewlink" data-pltdoc="x">Bibliography</a></td></tr><tr><td align="right"></td><td><a href="doc-index.html" class="tocviewlink" data-pltdoc="x">Index</a></td></tr></table></div></div><div class="tocviewlist"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,"tocview_1");">▼</a></td><td>15 </td><td><a href="reflection.html" class="tocviewlink" data-pltdoc="x">Reflection and Dynamic Evaluation</a></td></tr></table><div class="tocviewsublistbottom" style="display: block;" id="tocview_1"><table cellspacing="0" cellpadding="0"><tr><td align="right">15.1 </td><td><a href="eval.html" class="tocviewlink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">eval</span></span></a></td></tr><tr><td align="right">15.2 </td><td><a href="mk-namespace.html" class="tocviewlink" data-pltdoc="x">Manipulating Namespaces</a></td></tr><tr><td align="right">15.3 </td><td><a href="" class="tocviewselflink" data-pltdoc="x">Scripting Evaluation and Using <span class="RktSym"><span class="RktValLink">load</span></span></a></td></tr></table></div></div></div></div><div class="maincolumn"><div class="main"><div class="navsettop"><span class="navleft"><form class="searchform"><input class="searchbox" style="color: #888;" type="text" value="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, "6.1", "../");" onfocus="this.style.color="black"; this.style.textAlign="left"; if (this.value == "...search manuals...") this.value="";" onblur="if (this.value.match(/^ *$/)) { this.style.color="#888"; this.style.textAlign="center"; this.value="...search manuals..."; }"/></form> <a href="../index.html" title="up to the documentation top" data-pltdoc="x" onclick="return GotoPLTRoot("6.1");">top</a></span><span class="navright"> <a href="mk-namespace.html" title="backward to "15.2 Manipulating Namespaces"" data-pltdoc="x">← prev</a> <a href="reflection.html" title="up to "15 Reflection and Dynamic Evaluation"" data-pltdoc="x">up</a> <a href="macros.html" title="forward to "16 Macros"" data-pltdoc="x">next →</a></span> </div><h4 x-source-module="(lib "scribblings/guide/guide.scrbl")" x-part-tag=""load"">15.3<tt> </tt><a name="(part._load)"></a>Scripting Evaluation and Using <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span></h4><p>Historically, Lisp implementations did not offer module
systems. Instead, large programs were built by essentially scripting
the <a href="intro.html#%28tech._repl%29" class="techoutside" data-pltdoc="x"><span class="techinside">REPL</span></a> to evaluate program fragments in a particular order.
While <a href="intro.html#%28tech._repl%29" class="techoutside" data-pltdoc="x"><span class="techinside">REPL</span></a> scripting turns out to be a bad way to structure
programs and libraries, it is still sometimes a useful capability.</p><blockquote class="refpara"><blockquote class="refcolumn"><blockquote class="refcontent"><p>Describing a program via <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span> interacts
especially badly with macro-defined language extensions
[<a href="doc-bibliography.html#%28cite._.Flatt02%29" data-pltdoc="x">Flatt02</a>].</p></blockquote></blockquote></blockquote><p>The <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span> function runs a <a href="intro.html#%28tech._repl%29" class="techoutside" data-pltdoc="x"><span class="techinside">REPL</span></a> script by
<span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=Reading.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._read%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">read</a></span>ing S-expressions from a file, one by one, and passing
them to <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._eval%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">eval</a></span>. If a file <span class="stt">"place.rkts"</span> contains</p><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=define.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktSym">city</span><span class="hspace"> </span><span class="RktVal">"Salt Lake City"</span><span class="RktPn">)</span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=define.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktSym">state</span><span class="hspace"> </span><span class="RktVal">"Utah"</span><span class="RktPn">)</span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=Writing.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._printf%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">printf</a></span><span class="hspace"> </span><span class="RktVal">"~a, ~a\n"</span><span class="hspace"> </span><span class="RktSym">city</span><span class="hspace"> </span><span class="RktSym">state</span><span class="RktPn">)</span></td></tr></table></blockquote><p>then it can be loaded in a <a href="intro.html#%28tech._repl%29" class="techoutside" data-pltdoc="x"><span class="techinside">REPL</span></a>:</p><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span><span class="hspace"> </span><span class="RktVal">"place.rkts"</span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktOut">Salt Lake City, Utah</span></p></td></tr><tr><td><table cellspacing="0" cellpadding="0"><tr><td></td></tr></table></td></tr><tr><td><span class="stt">> </span><span class="RktSym">city</span></td></tr><tr><td><p><span class="RktRes">"Salt Lake City"</span></p></td></tr></table></blockquote><p>Since <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span> uses <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._eval%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">eval</a></span>, however, a module like the
following generally will not work—<wbr></wbr>for the same reasons described in
<a href="eval.html#%28part._namespaces%29" data-pltdoc="x">Namespaces</a>:</p><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><a href="Module_Syntax.html#%28part._hash-lang%29" class="RktModLink" data-pltdoc="x"><span class="RktMod">#lang</span></a><span class="hspace"> </span><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=index.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket</span></a></td></tr><tr><td><span class="hspace"> </span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=define.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktSym">there</span><span class="hspace"> </span><span class="RktVal">"Utopia"</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span><span class="hspace"> </span><span class="RktVal">"here.rkts"</span><span class="RktPn">)</span></td></tr></table></blockquote><p>The current namespace for evaluating the content of
<span class="stt">"here.rkts"</span> is likely to be empty; in any case, you cannot get
<span class="RktSym">there</span> from <span class="stt">"here.rkts"</span>. Also, any definitions in
<span class="stt">"here.rkts"</span> will not become visible for use within the module;
after all, the <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span> happens dynamically, while references to
identifiers within the module are resolved lexically, and therefore
statically.</p><p>Unlike <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._eval%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">eval</a></span>, <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span> does not accept a namespace
argument. To supply a namespace to <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span>, set the
<span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=Namespaces.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._current-namespace%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">current-namespace</a></span> <a href="parameterize.html#%28tech._parameter%29" class="techoutside" data-pltdoc="x"><span class="techinside">parameter</span></a>. The following example evaluates
the expressions in <span class="stt">"here.rkts"</span> using the bindings of the
<a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=index.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket/base</span></a> module:</p><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><a href="Module_Syntax.html#%28part._hash-lang%29" class="RktModLink" data-pltdoc="x"><span class="RktMod">#lang</span></a><span class="hspace"> </span><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=index.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket</span></a></td></tr><tr><td><span class="hspace"> </span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=parameters.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fmore-scheme..rkt%2529._parameterize%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">parameterize</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktPn">[</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=Namespaces.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._current-namespace%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">current-namespace</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=Namespaces.html%23%2528def._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._make-base-namespace%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">make-base-namespace</a></span><span class="RktPn">)</span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span><span class="hspace"> </span><span class="RktVal">"here.rkts"</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></blockquote><p>You can even use <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=Namespaces.html%23%2528def._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._namespace-anchor-%7E3enamespace%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">namespace-anchor->namespace</a></span> to make the
bindings of the enclosing module accessible for dynamic evaluation. In
the following example, when <span class="stt">"here.rkts"</span> is <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span>ed, it
can refer to <span class="RktSym">there</span> as well as the bindings of
<a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=index.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket</span></a>:</p><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><a href="Module_Syntax.html#%28part._hash-lang%29" class="RktModLink" data-pltdoc="x"><span class="RktMod">#lang</span></a><span class="hspace"> </span><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=index.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket</span></a></td></tr><tr><td><span class="hspace"> </span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=define.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktSym">there</span><span class="hspace"> </span><span class="RktVal">"Utopia"</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=Namespaces.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define-namespace-anchor%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">define-namespace-anchor</a></span><span class="hspace"> </span><span class="RktSym">a</span><span class="RktPn">)</span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=parameters.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fmore-scheme..rkt%2529._parameterize%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">parameterize</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktPn">[</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=Namespaces.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._current-namespace%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">current-namespace</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=Namespaces.html%23%2528def._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._namespace-anchor-%7E3enamespace%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">namespace-anchor->namespace</a></span><span class="hspace"> </span><span class="RktSym">a</span><span class="RktPn">)</span><span class="RktPn">]</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span><span class="hspace"> </span><span class="RktVal">"here.rkts"</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></blockquote><p>Still, if <span class="stt">"here.rkts"</span> defines any identifiers, the definitions
cannot be directly (i.e., statically) referenced by in the enclosing
module.</p><p>The <a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=load-lang.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket/load</span></a> module language is different from
<a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=index.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket</span></a> or <a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=index.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket/base</span></a>. A module using
<a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=load-lang.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket/load</span></a> treats all of its content as dynamic,
passing each form in the module body to <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._eval%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">eval</a></span> (using a
namespace that is initialized with <a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=index.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket</span></a>). As a
result, uses of <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._eval%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">eval</a></span> and <span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span> in the module body see
the same dynamic namespace as immediate body forms. For example, if
<span class="stt">"here.rkts"</span> contains</p><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=define.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktSym">here</span><span class="hspace"> </span><span class="RktVal">"Morporkia"</span><span class="RktPn">)</span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=define.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">go!</span><span class="RktPn">)</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=set_.html%23%2528form._%2528%2528quote._%7E23%7E25kernel%2529._set%2521%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">set!</a></span><span class="hspace"> </span><span class="RktSym">here</span><span class="hspace"> </span><span class="RktSym">there</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></blockquote><p>then running</p><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><a href="Module_Syntax.html#%28part._hash-lang%29" class="RktModLink" data-pltdoc="x"><span class="RktMod">#lang</span></a><span class="hspace"> </span><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=load-lang.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket/load</span></a></td></tr><tr><td><span class="hspace"> </span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=define.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktSym">there</span><span class="hspace"> </span><span class="RktVal">"Utopia"</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=eval.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._load%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">load</a></span><span class="hspace"> </span><span class="RktVal">"here.rkts"</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym">go!</span><span class="RktPn">)</span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=Writing.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._printf%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">printf</a></span><span class="hspace"> </span><span class="RktVal">"~a\n"</span><span class="hspace"> </span><span class="RktSym">here</span><span class="RktPn">)</span></td></tr></table></blockquote><p>prints “Utopia”.</p><p>Drawbacks of using <a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=load-lang.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket/load</span></a> include reduced
error checking, tool support, and performance. For example, with the
program</p><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><a href="Module_Syntax.html#%28part._hash-lang%29" class="RktModLink" data-pltdoc="x"><span class="RktMod">#lang</span></a><span class="hspace"> </span><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=load-lang.html&version=6.1" class="RktModLink Sq" data-pltdoc="x"><span class="RktSym">racket/load</span></a></td></tr><tr><td><span class="hspace"> </span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=define.html%23%2528form._%2528%2528lib._racket%252Fprivate%252Fbase..rkt%2529._define%2529%2529&version=6.1" class="RktStxLink Sq" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktSym">good</span><span class="hspace"> </span><span class="RktVal">5</span><span class="RktPn">)</span></td></tr><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://download.racket-lang.org/docs/6.1/html/local-redirect/index.html?doc=reference&rel=Writing.html%23%2528def._%2528%2528quote._%7E23%7E25kernel%2529._printf%2529%2529&version=6.1" class="RktValLink Sq" data-pltdoc="x">printf</a></span><span class="hspace"> </span><span class="RktVal">"running\n"</span><span class="RktPn">)</span></td></tr><tr><td><span class="RktSym">good</span></td></tr><tr><td><span class="RktSym">bad</span></td></tr></table></blockquote><p>DrRacket’s <span class="ssansserif">Check Syntax</span> tool cannot tell that the second
<span class="RktSym">good</span> is a reference to the first, and the unbound reference
to <span class="RktSym">bad</span> is reported only at run time instead of rejected
syntactically.</p><div class="navsetbottom"><span class="navleft"><form class="searchform"><input class="searchbox" style="color: #888;" type="text" value="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, "6.1", "../");" onfocus="this.style.color="black"; this.style.textAlign="left"; if (this.value == "...search manuals...") this.value="";" onblur="if (this.value.match(/^ *$/)) { this.style.color="#888"; this.style.textAlign="center"; this.value="...search manuals..."; }"/></form> <a href="../index.html" title="up to the documentation top" data-pltdoc="x" onclick="return GotoPLTRoot("6.1");">top</a></span><span class="navright"> <a href="mk-namespace.html" title="backward to "15.2 Manipulating Namespaces"" data-pltdoc="x">← prev</a> <a href="reflection.html" title="up to "15 Reflection and Dynamic Evaluation"" data-pltdoc="x">up</a> <a href="macros.html" title="forward to "16 Macros"" data-pltdoc="x">next →</a></span> </div></div></div><div id="contextindicator"> </div></body></html>
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