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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>12.3 Syntax Object Bindings</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" c
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<span class="RktVar">b-id</span> (or vice versa) if the identifiers were substituted in a
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suitable expression context at the <a href="syntax-model.html#%28tech._phase._level%29" class="techoutside" data-pltdoc="x"><span class="techinside">phase level</span></a> indicated by
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<span class="RktVar">phase-level</span>, <span class="RktVal">#f</span> otherwise. A <span class="RktVal">#f</span> value for
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<span class="RktVar">phase-level</span> corresponds to the <a href="syntax-model.html#%28tech._label._phase._level%29" class="techoutside" data-pltdoc="x"><span class="techinside">label phase level</span></a>.</div></p><p><div class="SIntrapara">Examples:</div><div class="SIntrapara"><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="define.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._define-syntax%29%29" class="RktStxLink" data-pltdoc="x">define-syntax</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">check</span><span class="hspace"> </span><span class="RktSym">stx</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29._syntax-case%29%29" class="RktStxLink" data-pltdoc="x">syntax-case</a></span><span class="hspace"> </span><span class="RktSym">stx</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">[</span><span class="RktPn">(</span><span class="RktSym"><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="hspace"> </span><span class="RktSym">x</span><span class="hspace"> </span><span class="RktSym">y</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28quote._~23~25kernel%29._if%29%29" class="RktStxLink" data-pltdoc="x">if</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._bound-identifier~3d~3f%29%29" class="RktValLink" data-pltdoc="x">bound-identifier=?</a></span><span class="hspace"> </span><span class="RktRdr">#'</span><span class="RktSym">x</span><span class="hspace"> </span><span class="RktRdr">#'</span><span class="RktSym">y</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktRdr">#'</span><span class="RktPn">(</span><span class="RktSym"><a href="let.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._let%29%29" class="RktStxLink" data-pltdoc="x">let</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktPn">[</span><span class="RktSym">y</span><span class="hspace"> </span><span class="RktVal">'</span><span class="RktVal">wrong</span><span class="RktPn">]</span><span class="RktPn">)</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="let.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._let%29%29" class="RktStxLink" data-pltdoc="x">let</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktPn">[</span><span class="RktSym">x</span><span class="hspace"> </span><span class="RktVal">'</span><span class="RktVal">binds</span><span class="RktPn">]</span><span class="RktPn">)</span><span class="hspace"> </span><span class="RktSym">y</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktRdr">#'</span><span class="RktPn">(</span><span class="RktSym"><a href="let.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._let%29%29
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<a href="syntax-model.html#%28tech._local._binding%29" class="techoutside" data-pltdoc="x"><span class="techinside">local binding</span></a>, <a href="syntax-model.html#%28tech._module._binding%29" class="techoutside" data-pltdoc="x"><span class="techinside">module binding</span></a>, or <a href="syntax-model.html#%28tech._top._level._binding%29" class="techoutside" data-pltdoc="x"><span class="techinside">top-level
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binding</span></a>—<wbr></wbr>perhaps via <a href="syntax-model.html#%28tech._rename._transformer%29" class="techoutside" data-pltdoc="x"><span class="techinside">rename transformers</span></a>—<wbr></wbr>at the <a href="syntax-model.html#%28tech._phase._level%29" class="techoutside" data-pltdoc="x"><span class="techinside">phase
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levels</span></a> indicated by <span class="RktVar">a-phase-level</span> and
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<span class="RktVar">b-phase-level</span>, respectively. A <span class="RktVal">#f</span> value for
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<span class="RktVar">a-phase-level</span> or <span class="RktVar">b-phase-level</span> corresponds to the
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<a href="syntax-model.html#%28tech._label._phase._level%29" class="techoutside" data-pltdoc="x"><span class="techinside">label phase level</span></a>.</div></p><p>“Same module binding” means that the identifiers refer to the same
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original definition site, and not necessarily to the same
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<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> or <span class="RktSym"><a href="require.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._provide%29%29" class="RktStxLink" data-pltdoc="x">provide</a></span> site. Due to renaming in
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<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> and <span class="RktSym"><a href="require.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._provide%29%29" class="RktStxLink" data-pltdoc="x">provide</a></span>, or due to a transformer binding
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to a <a href="syntax-model.html#%28tech._rename._transformer%29" class="techoutside" data-pltdoc="x"><span class="techinside">rename transformer</span></a>, the identifiers may return distinct
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results with <span class="RktSym"><a href="stxops.html#%28def._%28%28quote._~23~25kernel%29._syntax-e%29%29" class="RktValLink" data-pltdoc="x">syntax-e</a></span>.</p><p><div class="SIntrapara">Examples:</div><div class="SIntrapara"><blockquote class="SCodeFlow"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym"><a href="define.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._define-syntax%29%29" class="RktStxLink" data-pltdoc="x">define-syntax</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">check</span><span class="hspace"> </span><span class="RktSym">stx</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29._syntax-case%29%29" class="RktStxLink" data-pltdoc="x">syntax-case</a></span><span class="hspace"> </span><span class="RktSym">stx</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">[</span><span class="RktPn">(</span><span class="RktSym"><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="hspace"> </span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="if.html#%28form._%28%28quote._~23~25kernel%29._if%29%29" class="RktStxLink" data-pltdoc="x">if</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._free-identifier~3d~3f%29%29" class="RktValLink" data-pltdoc="x">free-identifier=?</a></span><span class="hspace"> </span><span class="RktRdr">#'</span><span class="RktSym"><a href="pairs.html#%28def._%28%28quote._~23~25kernel%29._car%29%29" class="RktValLink" data-pltdoc="x">car</a></span><span class="hspace"> </span><span class="RktRdr">#'</span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktRdr">#'</span><span class="RktPn">(</span><span class="RktSym"><a href="pairs.html#%28def._%28%28quote._~23~25kernel%29._list%29%29" class="RktValLink" data-pltdoc="x">list</a></span><span class="hspace"> </span><span class="RktVal">'</span><span class="RktVal">same:</span><span class="hspace"> </span><span class="RktSym">x</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="hspace"> </span><span class="RktRdr">#'</span><span class="RktPn">(</span><span class="RktSym"><a href="pairs.html#%28def._%28%28quote._~23~25kernel%29._list%29%29" class="RktValLink" data-pltdoc="x">list</a></span><span class="hspace"> </span><span class="RktVal">'</span><span class="RktVal">different:</span><span class="hspace"> </span><span class="RktSym">x</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">]</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></td></tr><tr><td><span class="stt">> </span><span class="RktPn">(</span><span class="RktSym">check</span><span class="hspace"> </span><span class="RktSym"><a href="pairs.html#%28def._%28%28quote._~23~25kernel%29._car%29%29" class="RktValLink" data-pltdoc="x">car</a></span><span class="RktPn">)</span></td></tr><tr><td><p><span class="RktRes">'(same: #<proce
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in the list with <span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._bound-identifier~3d~3f%29%29" class="RktValLink" data-pltdoc="x">bound-identifier=?</a></span>. If any comparison
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returns <span class="RktVal">#t</span>, one of the duplicate identifiers is returned (the
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first one in <span class="RktVar">ids</span> that is a duplicate), otherwise the result
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is <span class="RktVal">#f</span>.</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>procedure</p></div></div><table cellspacing="0" cellpadding="0" class="prototype RForeground"><tr><td valign="top"><span class="RktPn">(</span><a name="(def._((quote._~23~25kernel)._identifier-binding))"></a><span title="Provided from: racket/base, racket | Package: base"><span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._identifier-binding%29%29" class="RktValDef RktValLink" data-pltdoc="x">identifier-binding</a></span></span></td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="RktVar">id-stx</span></td><td valign="top"><span class="hspace"> </span></td></tr><tr><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="hspace"> </span><span class="RktOpt">[</span></td><td valign="top"><span class="RktVar">phase-level</span></td><td valign="top"><span class="hspace"> </span></td></tr><tr><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="RktVar">top-level-symbol?</span><span class="RktOpt">]</span><span class="RktPn">)</span></td><td valign="top"><span class="hspace"> </span></td></tr></table></blockquote></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="prototype"><tr><td valign="top"><span class="hspace"> </span></td><td valign="top">→</td><td valign="top"><span class="hspace"> </span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace"> </span><span class="RktVal">'</span><span class="RktVal">lexical</span></td></tr><tr><td><span class="hspace"> </span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._list%2Fc%29%29" class="RktValLink" data-pltdoc="x">list/c</a></span><span class="hspace"> </span><span class="RktSym"><a href="Module_Names_and_Loading.html#%28def._%28%28quote._~23~25kernel%29._module-path-index~3f%29%29" class="RktValLink" data-pltdoc="x">module-path-index?</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym"><a href="Module_Names_and_Loading.html#%28def._%28%28quote._~23~25kernel%29._module-path-index~3f%29%29" class="RktValLink" data-pltdoc="x">module-path-index?</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._exact-nonnegative-integer~3f%29%29" class="RktValLink" data-pltdoc="x">exact-nonnegative-integer?</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym"><a hre
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or four (if <span class="RktVar">top-level-symbol?</span> is true) kinds of values, depending on the binding of
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<span class="RktVar">id-stx</span> at the <a href="syntax-model.html#%28tech._phase._level%29" class="techoutside" data-pltdoc="x"><span class="techinside">phase level</span></a> indicated by
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<span class="RktVar">phase-level</span> (where a <span class="RktVal">#f</span> value for
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<span class="RktVar">phase-level</span> corresponds to the <a href="syntax-model.html#%28tech._label._phase._level%29" class="techoutside" data-pltdoc="x"><span class="techinside">label phase level</span></a>):</div></p><ul><li><p>The result is <a name="(idx._(gentag._231._(lib._scribblings/reference/reference..scrbl)))"></a><span class="RktVal">'</span><span class="RktVal">lexical</span> if <span class="RktVar">id-stx</span>
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has a <a href="syntax-model.html#%28tech._local._binding%29" class="techoutside" data-pltdoc="x"><span class="techinside">local binding</span></a>.</p></li><li><p>The result is a list of seven items when <span class="RktVar">id-stx</span>
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has a <a href="syntax-model.html#%28tech._module._binding%29" class="techoutside" data-pltdoc="x"><span class="techinside">module binding</span></a>: <span class="RktPn">(</span><span class="RktSym"><a href="pairs.html#%28def._%28%28quote._~23~25kernel%29._list%29%29" class="RktValLink" data-pltdoc="x">list</a></span><span class="stt"> </span><span class="RktVar">from-mod</span><span class="stt"> </span><span class="RktVar">from-sym</span><span class="stt"> </span><span class="RktVar">nominal-from-mod</span><span class="stt"> </span><span class="RktVar">nominal-from-sym</span><span class="stt"> </span><span class="RktVar">from-phase</span><span class="stt"> </span><span class="RktVar">import-phase+space-shift</span><span class="stt"> </span><span class="RktVar">nominal-export-phase</span><span class="RktPn">)</span>.</p><ul><li><p><span class="RktVar">from-mod</span> is a module path index (see
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<a href="Module_Names_and_Loading.html#%28part._modpathidx%29" data-pltdoc="x">Compiled Modules and References</a>) that indicates the defining module. It
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is the “self” module path index if the binding refers to a
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definition in the enclosing module of <span class="RktVar">id-stx</span>.</p></li><li><p><span class="RktVar">from-sym</span> is a symbol for the identifier’s name
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at its definition site in the originating module. This can be
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different from the local name returned by
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<span class="RktSym"><a href="stxops.html#%28def._%28%28quote._~23~25kernel%29._syntax-~3edatum%29%29" class="RktValLink" data-pltdoc="x">syntax->datum</a></span> for several reasons: the identifier is
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renamed on import, it is renamed on export, or it is
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implicitly renamed because the binding site was generated by a
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macro invocation. In that last case, it may be an
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<a href="symbols.html#%28tech._unreadable._symbol%29" class="techoutside" data-pltdoc="x"><span class="techinside">unreadable symbol</span></a>, and it may be different from the
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result of <span class="RktSym"><a href="stxops.html#%28def._%28%28quote._~23~25kernel%29._syntax-~3edatum%29%29" class="RktValLink" data-pltdoc="x">syntax->datum</a></span> on the identifier in the
|
||
|
|
original source definition.</p></li><li><p><span class="RktVar">nominal-from-mod</span> is a module path index (see
|
||
|
|
<a href="Module_Names_and_Loading.html#%28part._modpathidx%29" data-pltdoc="x">Compiled Modules and References</a>) that indicates the binding’s module as
|
||
|
|
it appears locally in the source around <span class="RktVar">id-stx</span>: it
|
||
|
|
indicates a module <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>d into the context of
|
||
|
|
<span class="RktVar">id-stx</span> to provide its binding, or it is the same
|
||
|
|
“self” as <span class="RktVar">from-mod</span> for a binding that refers to a
|
||
|
|
definition in the enclosing module of <span class="RktVar">id-stx</span>. It can
|
||
|
|
be different from <span class="RktVar">from-mod</span> due to a re-export in
|
||
|
|
<span class="RktVar">nominal-from-mod</span> of some imported identifier. If the
|
||
|
|
same binding is imported in multiple ways, an arbitrary
|
||
|
|
representative is chosen.</p></li><li><p><span class="RktVar">nominal-from-sym</span> is a symbol for the binding’s
|
||
|
|
identifier as it appears locally in the source around
|
||
|
|
<span class="RktVar">id-stx</span>: it is the identifier’s name as exported by
|
||
|
|
<span class="RktVar">nominal-from-mod</span>, or it is the source identifier’s
|
||
|
|
symbol for a definition within the enclosing module of
|
||
|
|
<span class="RktVar">id-stx</span>. It can be different from <span class="RktVar">from-sym</span>
|
||
|
|
due to a renaming <span class="RktSym"><a href="require.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._provide%29%29" class="RktStxLink" data-pltdoc="x">provide</a></span>, even if <span class="RktVar">from-mod</span>
|
||
|
|
and <span class="RktVar">nominal-from-mod</span> are the same, or due to a
|
||
|
|
definition that was introduced by a macro expansion.</p></li><li><p><span class="RktVar">from-phase</span> is an exact non-negative integer
|
||
|
|
representing the originating phase. For example, it is
|
||
|
|
<span class="RktVal">1</span> if the definition is for-syntax.</p></li><li><p><span class="RktVar">import-phase+space-shift</span> is <span class="RktVal">0</span> if the binding
|
||
|
|
import of <span class="RktVar">nominal-from-mode</span> is from a definition
|
||
|
|
or a plain <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>, <span class="RktVal">1</span> if it is from a
|
||
|
|
<span class="RktSym"><a href="require.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._for-syntax%29%29" class="RktStxLink" data-pltdoc="x">for-syntax</a></span> import, a phase combined with a space name if it
|
||
|
|
is from a <span class="RktSym"><a href="require.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._for-space%29%29" class="RktStxLink" data-pltdoc="x">for-space</a></span> import, etc.</p></li><li><p><span class="RktVar">nominal-export-phase+space</span> is the <a href="syntax-model.html#%28tech._phase._level%29" class="techoutside" data-pltdoc="x"><span class="techinside">phase level</span></a>
|
||
|
|
and <a href="syntax-model.html#%28tech._binding._space%29" class="techoutside" data-pltdoc="x"><span class="techinside">binding space</span></a>
|
||
|
|
of the export from <span class="RktVar">nominal-from-mod</span> for an
|
||
|
|
imported binding, or it is the phase level of the definition for a
|
||
|
|
binding from the enclosing module of <span class="RktVar">id-stx</span>.</p></li></ul></li><li><p>The result is <span class="RktPn">(</span><span class="RktSym"><a href="pairs.html#%28def._%28%28quote._~23~25kernel%29._list%29%29" class="RktValLink" data-pltdoc="x">list</a></span><span class="stt"> </span><span class="RktVar">top-sym</span><span class="RktPn">)</span> if <span class="RktVar">id-stx</span>
|
||
|
|
has a <a href="syntax-model.html#%28tech._top._level._binding%29" class="techoutside" data-pltdoc="x"><span class="techinside">top-level binding</span></a> and
|
||
|
|
<span class="RktVar">top-level-symbol?</span> is true. The <span class="RktVar">top-sym</span>
|
||
|
|
can different from the name returned by
|
||
|
|
<span class="RktSym"><a href="stxops.html#%28def._%28%28quote._~23~25kernel%29._syntax-~3edatum%29%29" class="RktValLink" data-pltdoc="x">syntax->datum</a></span> when the binding definition was
|
||
|
|
generated by a macro invocation.</p></li><li><p>The result is <span class="RktVal">#f</span> if <span class="RktVar">id-stx</span> has a
|
||
|
|
<a href="syntax-model.html#%28tech._top._level._binding%29" class="techoutside" data-pltdoc="x"><span class="techinside">top-level binding</span></a> and <span class="RktVar">top-level-symbol?</span> is
|
||
|
|
<span class="RktVal">#f</span> or if <span class="RktVar">id-stx</span> is <a href="syntax-model.html#%28tech._unbound%29" class="techoutside" data-pltdoc="x"><span class="techinside">unbound</span></a>. An
|
||
|
|
unbound identifier is typically treated the same as an
|
||
|
|
identifier whose top-level binding is a variable.</p></li></ul><p>If <span class="RktVar">id-stx</span> is bound to a <a href="syntax-model.html#%28tech._rename._transformer%29" class="techoutside" data-pltdoc="x"><span class="techinside">rename-transformer</span></a>, the result
|
||
|
|
from <span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._identifier-binding%29%29" class="RktValLink" data-pltdoc="x">identifier-binding</a></span> is for the identifier in the
|
||
|
|
transformer, so that <span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._identifier-binding%29%29" class="RktValLink" data-pltdoc="x">identifier-binding</a></span> is consistent with
|
||
|
|
<span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._free-identifier~3d~3f%29%29" class="RktValLink" data-pltdoc="x">free-identifier=?</a></span>.</p><p class="SHistory">Changed in version 6.6.0.4 of package <span class="stt">base</span>: Added the <span class="RktVar">top-level-symbol?</span> argument to report
|
||
|
|
information on top-level bindings.<br/>Changed in version 8.2.0.3: Generalized phase results to phase–space combinations.</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>procedure</p></div></div><table cellspacing="0" cellpadding="0" class="prototype RForeground"><tr><td valign="top"><span class="RktPn">(</span><a name="(def._((quote._~23~25kernel)._identifier-transformer-binding))"></a><span title="Provided from: racket/base, racket | Package: base"><span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._identifier-transformer-binding%29%29" class="RktValDef RktValLink" data-pltdoc="x">identifier-transformer-binding</a></span></span></td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="RktVar">id-stx</span></td><td valign="top"><span class="hspace"> </span></td></tr><tr><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="hspace"> </span><span class="RktOpt">[</span></td><td valign="top"><span class="RktVar">rt-phase-level</span><span class="RktOpt">]</span><span class="RktPn">)</span></td><td valign="top"><span class="hspace"> </span></td></tr></table></blockquote></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="prototype"><tr><td valign="top"><span class="hspace"> </span></td><td valign="top">→</td><td valign="top"><span class="hspace"> </span></td><td valign="top"><table cellspacing="0" cellpadding="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace"> </span><span class="RktVal">'</span><span class="RktVal">lexical</span></td></tr><tr><td><span class="hspace"> </span><span class="RktVal">#f</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._listof%29%29" class="RktValLink" data-pltdoc="x">listof</a></span><span class="hspace"> </span><span class="RktSym"><a href="Module_Names_and_Loading.html#%28def._%28%28quote._~23~25kernel%29._module-path-index~3f%29%29" class="RktValLink" data-pltdoc="x">module-path-index?</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym"><a href="Module_Names_and_Loading.html#%28def._%28%28quote._~23~25kernel%29._module-path-index~3f%29%29" class="RktValLink" data-pltdoc="x">module-path-index?</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._exact-nonnegative-integer~3f%29%29" class="RktValLink" data-pltdoc="x">exact-nonnegative-integer?</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym"><a href="phase_space.html#%28def._%28%28lib._racket%2Fphase%2Bspace..rkt%29._phase%2Bspace-shift~3f%29%29" class="RktValLink"
|
||
|
|
is <span class="RktVal">#f</span> if the binding for <span class="RktVar">id-stx</span> has scopes that are
|
||
|
|
a subset of the scopes for <span class="RktVar">wrt-id-stx</span>. That is, if
|
||
|
|
<span class="RktVar">id-stx</span> and <span class="RktVar">wrt-id-stx</span> have the same symbolic name, a
|
||
|
|
binding for <span class="RktVar">id-stx</span> is returned only if the binding does not
|
||
|
|
also apply to <span class="RktVar">wrt-id-stx</span>.</div></p><p class="SHistory">Added in version 8.3.0.8 of package <span class="stt">base</span>.</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>procedure</p></div></div><table cellspacing="0" cellpadding="0" class="prototype RForeground"><tr><td valign="top"><span class="RktPn">(</span><a name="(def._((quote._~23~25kernel)._identifier-binding-symbol))"></a><span title="Provided from: racket/base, racket | Package: base"><span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._identifier-binding-symbol%29%29" class="RktValDef RktValLink" data-pltdoc="x">identifier-binding-symbol</a></span></span></td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="RktVar">id-stx</span></td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="hspace"> </span></td></tr><tr><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="hspace"> </span><span class="RktOpt">[</span></td><td valign="top"><span class="RktVar">phase-level</span><span class="RktOpt">]</span><span class="RktPn">)</span></td><td valign="top"><span class="hspace"> </span></td><td valign="top">→</td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="RktSym"><a href="symbols.html#%28def._%28%28quote._~23~25kernel%29._symbol~3f%29%29" class="RktValLink" data-pltdoc="x">symbol?</a></span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace"> </span><span class="RktVar">id-stx</span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym"><a href="stxops.html#%28def._%28%28lib._racket%2Fprivate%2Fstx..rkt%29._identifier~3f%29%29" class="RktValLink" data-pltdoc="x">identifier?</a></span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="RktVar">phase-level</span></td><td valign="top"><span class="hspace"> </span></td><td valign="top">:</td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace"> </span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._exact-integer~3f%29%29" class="RktValLink" data-pltdoc="x">exact-integer?</a></span><span class="hspace"> </span><span class="RktVal">#f</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="hspace"> </span></td><td valign="top">=</td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="stxtrans.html#%28def._%28%28quote._~23~25kernel%29._syntax-local-phase-level%29%29" class="RktValLink" data-pltdoc="x">syntax-local-phase-level</a></span><span class="RktPn">)</span></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">Like <span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._identifier-binding%29%29" class="RktValLink" data-pltdoc="x">identifier-binding</a></span>, but produces a symbol that
|
||
|
|
corresponds to the binding. The symbol result is the same for any
|
||
|
|
identifiers that are <span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._free-identifier~3d~3f%29%29" class="RktValLink" data-pltdoc="x">free-identifier=?</a></span>, but the result may
|
||
|
|
also be the same for identifiers that are not
|
||
|
|
<span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._free-identifier~3d~3f%29%29" class="RktValLink" data-pltdoc="x">free-identifier=?</a></span> (i.e., different symbols imply different
|
||
|
|
bindings, but the same symbol does not imply the same binding).</div></p><p>When <span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._identifier-binding%29%29" class="RktValLink" data-pltdoc="x">identifier-binding</a></span> would produce a list, then the second
|
||
|
|
element of that list is the result that
|
||
|
|
<span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._identifier-binding-symbol%29%29" class="RktValLink" data-pltdoc="x">identifier-binding-symbol</a></span> produces.</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>procedure</p></div></div><table cellspacing="0" cellpadding="0" class="prototype RForeground"><tr><td valign="top"><span class="RktPn">(</span><a name="(def._((quote._~23~25kernel)._identifier-binding-portal-syntax))"></a><span title="Provided from: racket/base, racket | Package: base"><span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._identifier-binding-portal-syntax%29%29" class="RktValDef RktValLink" data-pltdoc="x">identifier-binding-portal-syntax</a></span></span></td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="RktVar">id-stx</span></td><td valign="top"><span class="hspace"> </span></td></tr><tr><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="hspace"> </span><span class="RktOpt">[</span></td><td valign="top"><span class="RktVar">phase-level</span><span class="RktOpt">]</span><span class="RktPn">)</span></td><td valign="top"><span class="hspace"> </span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace"> </span>→<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace"> </span><span class="RktVal">#f</span><span class="hspace"> </span><span class="RktSym"><a href="stxops.html#%28def._%28%28quote._~23~25kernel%29._syntax~3f%29%29" class="RktValLink" data-pltdoc="x">syntax?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktVar">id-stx</span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym"><a href="stxops.html#%28def._%28%28lib._racket%2Fprivate%2Fstx..rkt%29._identifier~3f%29%29" class="RktValLink" data-pltdoc="x">identifier?</a></span></td></tr><tr><td><table cellspacing="0" cellpadding="0" class="argcontract"><tr><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="RktVar">phase-level</span></td><td valign="top"><span class="hspace"> </span></td><td valign="top">:</td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="data-structure-contracts.html#%28def._%28%28lib._racket%2Fcontract%2Fbase..rkt%29._or%2Fc%29%29" class="RktValLink" data-pltdoc="x">or/c</a></span><span class="hspace"> </span><span class="RktSym"><a href="number-types.html#%28def._%28%28quote._~23~25kernel%29._exact-integer~3f%29%29" class="RktValLink" data-pltdoc="x">exact-integer?</a></span><span class="hspace"> </span><span class="RktVal">#f</span><span class="RktPn">)</span></td></tr><tr><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="hspace"> </span></td><td valign="top">=</td><td valign="top"><span class="hspace"> </span></td><td valign="top"><span class="RktPn">(</span><span class="RktSym"><a href="stxtrans.html#%28def._%28%28quote._~23~25kernel%29._syntax-local-phase-level%29%29" class="RktValLink" data-pltdoc="x">syntax-local-phase-level</a></span><span class="RktPn">)</span></td></tr></table></td></tr></table></blockquote></div><div class="SIntrapara">If <span class="RktVar">id-stx</span> is bound at <span class="RktVar">phase-level</span> to <a href="stxtrans.html#%28tech._portal._syntax%29" class="techoutside" data-pltdoc="x"><span class="techinside">portal
|
||
|
|
syntax</span></a>, either via <span class="RktSym"><a href="define.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._define-syntax%29%29" class="RktStxLink" data-pltdoc="x">define-syntax</a></span> or <span class="RktSym"><a href="require.html#%28form._%28%28quote._~23~25kernel%29._~23~25require%29%29" class="RktStxLink" data-pltdoc="x">#%require</a></span>, then
|
||
|
|
the portal syntax content is returned. The module that binds
|
||
|
|
<span class="RktVar">id-stx</span> must be declared, but it need not be instantiated at
|
||
|
|
the relevant phase, and <span class="RktSym"><a href="stxcmp.html#%28def._%28%28quote._~23~25kernel%29._identifier-binding-portal-syntax%29%29" class="RktValLink" data-pltdoc="x">identifier-binding-portal-syntax</a></span> does
|
||
|
|
not instantiate the module.</div></p><p class="SHistory">Added in version 8.3.0.8 of package <span class="stt">base</span>.</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="stxops.html" title="backward to "12.2 Syntax Object Content"" data-pltdoc="x">← prev</a> <a href="Macros.html" title="up to "12 Macros"" data-pltdoc="x">up</a> <a href="stxtrans.html" title="forward to "12.4 Syntax Transformers"" data-pltdoc="x">next →</a></span> </div></div></div><div id="contextindicator"> </div></body></html>
|