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<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"/><meta name="viewport" content="width=device-width, initial-scale=0.8"/><title>12.11 File Inclusion</title><link rel="stylesheet" type="text/css" href="../scribble.css" title="default"/><link rel="stylesheet" type="text/css" href="extras.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">The Racket Reference</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="model.html" class="tocviewlink" data-pltdoc="x">Language Model</a></td></tr><tr><td align="right">2 </td><td><a href="notation.html" class="tocviewlink" data-pltdoc="x">Notation for Documentation</a></td></tr><tr><td align="right">3 </td><td><a href="syntax.html" class="tocviewlink" data-pltdoc="x">Syntactic Forms</a></td></tr><tr><td align="right">4 </td><td><a href="data.html" class="tocviewlink" data-pltdoc="x">Datatypes</a></td></tr><tr><td align="right">5 </td><td><a href="structures.html" class="tocviewlink" data-pltdoc="x">Structures</a></td></tr><tr><td align="right">6 </td><td><a href="mzlib_class.html" class="tocviewlink" data-pltdoc="x">Classes and Objects</a></td></tr><tr><td align="right">7 </td><td><a href="mzlib_unit.html" class="tocviewlink" data-pltdoc="x">Units</a></td></tr><tr><td align="right">8 </td><td><a href="contracts.html" class="tocviewlink" data-pltdoc="x">Contracts</a></td></tr><tr><td align="right">9 </td><td><a href="match.html" class="tocviewlink" data-pltdoc="x">Pattern Matching</a></td></tr><tr><td align="right">10 </td><td><a href="control.html" class="tocviewlink" data-pltdoc="x">Control Flow</a></td></tr><tr><td align="right">11 </td><td><a href="concurrency.html" class="tocviewlink" data-pltdoc="x">Concurrency and Parallelism</a></td></tr><tr><td align="right">12 </td><td><a href="Macros.html" class="tocviewselflink" data-pltdoc="x">Macros</a></td></tr><tr><td align="right">13 </td><td><a href="input-and-output.html" class="tocviewlink" data-pltdoc="x">Input and Output</a></td></tr><tr><td align="right">14 </td><td><a href="security.html" class="tocviewlink" data-pltdoc="x">Reflection and Security</a></td></tr><tr><td align="right">15 </td><td><a href="os.html" class="tocviewlink" data-pltdoc="x">Operating System</a></td></tr><tr><td align="right">16 </td><td><a href="memory.html" class="tocviewlink" data-pltdoc="x">Memory Management</a></td></tr><tr><td align="right">17 </td><td><a href="unsafe.html" class="tocviewlink" data-pltdoc="x">Unsafe Operations</a></td></tr><tr><td align="right">18 </td><td><a href="running.html" class="t
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place of the <span class="RktSym"><a href="include.html#%28form._%28%28lib._racket%2Finclude..rkt%29._include%29%29" class="RktStxLink" data-pltdoc="x">include</a></span> expression.</div></p><p>A <span class="RktVar">path-spec</span> resembles a subset of the <span class="RktVar">mod-path</span>
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forms for <span class="RktSym"><a href="require.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._require%29%29" class="RktStxLink" data-pltdoc="x">require</a></span>, but it specifies a file whose content need
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not be a module. That is, <span class="RktVar">string</span> refers to a file using a
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platform-independent relative path, <span class="RktPn">(</span><span class="RktSym"><a href="require.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._file%29%29" class="RktStxLink" data-pltdoc="x">file</a></span><span class="stt"> </span><span class="RktVar">string</span><span class="RktPn">)</span> refers to a
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file using platform-specific notation, and <span class="RktPn">(</span><span class="RktSym"><a href="require.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._lib%29%29" class="RktStxLink" data-pltdoc="x">lib</a></span><span class="stt"> </span><span class="RktVar">string</span><span class="stt"> </span><span class="RktMeta"><a href="stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29._......%29%29" class="RktStxLink" data-pltdoc="x">...</a></span><span class="RktPn">)</span>
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refers to a file within a collection.</p><p>If <span class="RktVar">path-spec</span> specifies a relative path, the path is resolved
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relative to the source for the <span class="RktSym"><a href="include.html#%28form._%28%28lib._racket%2Finclude..rkt%29._include%29%29" class="RktStxLink" data-pltdoc="x">include</a></span> expression, if that
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source is a complete path string. If the source is not a complete path
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string, then <span class="RktVar">path-spec</span> is resolved relative to
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<span class="RktPn">(</span><span class="RktSym"><a href="eval.html#%28def._%28%28quote._~23~25kernel%29._current-load-relative-directory%29%29" class="RktValLink" data-pltdoc="x">current-load-relative-directory</a></span><span class="RktPn">)</span> if it is not <span class="RktVal">#f</span>,
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or relative to <span class="RktPn">(</span><span class="RktSym"><a href="Filesystem.html#%28def._%28%28quote._~23~25kernel%29._current-directory%29%29" class="RktValLink" data-pltdoc="x">current-directory</a></span><span class="RktPn">)</span> otherwise.</p><p>The included syntax is given the lexical context of the
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<span class="RktSym"><a href="include.html#%28form._%28%28lib._racket%2Finclude..rkt%29._include%29%29" class="RktStxLink" data-pltdoc="x">include</a></span> expression, while the included syntax’s source
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location refers to its actual source.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>syntax</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(form._((lib._racket/include..rkt)._include-at/relative-to))"></a><span title="Provided from: racket/include, racket | Package: base"><span class="RktSym"><a href="include.html#%28form._%28%28lib._racket%2Finclude..rkt%29._include-at%2Frelative-to%29%29" class="RktStxDef RktStxLink" data-pltdoc="x">include-at/relative-to</a></span></span><span class="hspace"> </span><span class="RktVar">context</span><span class="hspace"> </span><span class="RktVar">source</span><span class="hspace"> </span><span class="RktVar">path-spec</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Like <span class="RktSym"><a href="include.html#%28form._%28%28lib._racket%2Finclude..rkt%29._include%29%29" class="RktStxLink" data-pltdoc="x">include</a></span>, except that the lexical context of
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<span class="RktVar">context</span> is used for the included syntax, and a relative
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<span class="RktVar">path-spec</span> is resolved with respect to the source of
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<span class="RktVar">source</span>. The <span class="RktVar">context</span> and <span class="RktVar">source</span> elements are
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otherwise discarded by expansion.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>syntax</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(form._((lib._racket/include..rkt)._include/reader))"></a><span title="Provided from: racket/include, racket | Package: base"><span class="RktSym"><a href="include.html#%28form._%28%28lib._racket%2Finclude..rkt%29._include%2Freader%29%29" class="RktStxDef RktStxLink" data-pltdoc="x">include/reader</a></span></span><span class="hspace"> </span><span class="RktVar">path-spec</span><span class="hspace"> </span><span class="RktVar">reader-expr</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Like <span class="RktSym"><a href="include.html#%28form._%28%28lib._racket%2Finclude..rkt%29._include%29%29" class="RktStxLink" data-pltdoc="x">include</a></span>, except that the procedure produced by the
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expression <span class="RktVar">reader-expr</span> is used to read the included file,
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instead of <span class="RktSym"><a href="Reading.html#%28def._%28%28quote._~23~25kernel%29._read-syntax%29%29" class="RktValLink" data-pltdoc="x">read-syntax</a></span>.</div></p><p>The <span class="RktVar">reader-expr</span> is evaluated at expansion time in the
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<a href="syntax-model.html#%28tech._transformer._environment%29" class="techoutside" data-pltdoc="x"><span class="techinside">transformer environment</span></a>. Since it serves as a replacement for
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<span class="RktSym"><a href="Reading.html#%28def._%28%28quote._~23~25kernel%29._read-syntax%29%29" class="RktValLink" data-pltdoc="x">read-syntax</a></span>, the expression’s value should be a procedure
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that consumes two inputs—<wbr></wbr>a string representing the source and an
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input port—<wbr></wbr>and produces a syntax object or <span class="RktSym"><a href="port-ops.html#%28def._%28%28quote._~23~25kernel%29._eof%29%29" class="RktValLink" data-pltdoc="x">eof</a></span>. The
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procedure will be called repeatedly until it produces <span class="RktSym"><a href="port-ops.html#%28def._%28%28quote._~23~25kernel%29._eof%29%29" class="RktValLink" data-pltdoc="x">eof</a></span>.</p><p>The syntax objects returned by the procedure should have source
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location information, but usually no lexical context; any lexical
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context in the syntax objects will be ignored.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" cellpadding="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>syntax</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(form._((lib._racket/include..rkt)._include-at/relative-to/reader))"></a><span title="Provided from: racket/include, racket | Package: base"><span class="RktSym"><a href="include.html#%28form._%28%28lib._racket%2Finclude..rkt%29._include-at%2Frelative-to%2Freader%29%29" class="RktStxDef RktStxLink" data-pltdoc="x">include-at/relative-to/reader</a></span></span><span class="hspace"> </span><span class="RktVar">context</span><span class="hspace"> </span><span class="RktVar">source</span><span class="hspace"> </span><span class="RktVar">path-spec</span><span class="hspace"> </span><span class="RktVar">reader-expr</span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Combines <span class="RktSym"><a href="include.html#%28form._%28%28lib._racket%2Finclude..rkt%29._include-at%2Frelative-to%29%29" class="RktStxLink" data-pltdoc="x">include-at/relative-to</a></span> and <span class="RktSym"><a href="include.html#%28form._%28%28lib._racket%2Finclude..rkt%29._include%2Freader%29%29" class="RktStxLink" data-pltdoc="x">include/reader</a></span>.</div></p><div class="navsetbottom"><span class="navleft"><form class="searchform"><input class="searchbox" id="searchbox" type="text" tabindex="1" placeholder="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, "8.6", "../");"/></form> <a href="https://docs.racket-lang.org/index.html" title="up to the documentation top" data-pltdoc="x" onclick="return GotoPLTRoot("8.6");">top</a><span class="tocsettoggle"> <a href="javascript:void(0);" title="show/hide table of contents" onclick="TocsetToggle();">contents</a></span></span><span class="navright"> <a href="Serializing_Syntax.html" title="backward to "12.10 Serializing Syntax"" data-pltdoc="x">← prev</a> <a href="Macros.html" title="up to "12 Macros"" data-pltdoc="x">up</a> <a href="syntax-util.html" title="forward to "12.12 Syntax Utilities"" data-pltdoc="x">next →</a></span> </div></div></div><div id="contextindicator"> </div></body></html>
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