/usr/share/doc/racket/reference/objectprinting.html is in racket-doc 6.7-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"/><title>6.10 Object Printing</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"><span style="font-weight: bold">The Racket Reference</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="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="tocviewselflink" 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="tocviewlink" 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="tocviewlink" data-pltdoc="x">Running Racket</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>6 </td><td><a href="mzlib_class.html" class="tocviewlink" data-pltdoc="x">Classes and Objects</a></td></tr></table><div class="tocviewsublistbottom" style="display: block;" id="tocview_1"><table cellspacing="0" cellpadding="0"><tr><td align="right">6.1 </td><td><a href="createinterface.html" class="tocviewlink" data-pltdoc="x">Creating Interfaces</a></td></tr><tr><td align="right">6.2 </td><td><a href="createclass.html" class="tocviewlink" data-pltdoc="x">Creating Classes</a></td></tr><tr><td align="right">6.3 </td><td><a href="objcreation.html" class="tocviewlink" data-pltdoc="x">Creating Objects</a></td></tr><tr><td align="right">6.4 </td><td><a href="ivaraccess.html" class="tocviewlink" data-pltdoc="x">Field and Method Access</a></td></tr><tr><td align="right">6.5 </td><td><a href="mixins.html" class="tocviewlink" data-pltdoc="x">Mixins</a></td></tr><tr><td align="right">6.6 </td><td><a href="trait.html" class="tocviewlink" data-pltdoc="x">Traits</a></td></tr><tr><td align="right">6.7 </td><td><a href="Object_and_Class_Contracts.html" class="tocviewlink" data-pltdoc="x">Object and Class Contracts</a></td></tr><tr><td align="right">6.8 </td><td><a href="objectequality.html" class="tocviewlink" data-pltdoc="x">Object Equality and Hashing</a></td></tr><tr><td align="right">6.9 </td><td><a href="objectserialize.html" class="tocviewlink" data-pltdoc="x">Object Serialization</a></td></tr><tr><td align="right">6.10 </td><td><a href="" class="tocviewselflink" data-pltdoc="x">Object Printing</a></td></tr><tr><td align="right">6.11 </td><td><a href="objectutils.html" class="tocviewlink" data-pltdoc="x">Object, Class, and Interface Utilities</a></td></tr><tr><td align="right">6.12 </td><td><a href="Surrogates.html" class="tocviewlink" data-pltdoc="x">Surrogates</a></td></tr></table></div></div></div><div class="tocsub"><div class="tocsubtitle">On this page:</div><table class="tocsublist" cellspacing="0"><tr><td><a href="#%28def._%28%28lib._racket%2Fprivate%2Fclass-internal..rkt%29._printable~3c~25~3e%29%29" class="tocsublink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">printable<%></span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._racket%2Fprivate%2Fclass-internal..rkt%29._writable~3c~25~3e%29%29" class="tocsublink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">writable<%></span></span></a></td></tr></table></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, "6.7", "../");" 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("6.7");">top</a></span><span class="navright"> <a href="objectserialize.html" title="backward to "6.9 Object Serialization"" data-pltdoc="x">← prev</a> <a href="mzlib_class.html" title="up to "6 Classes and Objects"" data-pltdoc="x">up</a> <a href="objectutils.html" title="forward to "6.11 Object, Class, and Interface Utilities"" data-pltdoc="x">next →</a></span> </div><h4 x-source-module="(lib "scribblings/reference/reference.scrbl")" x-source-pkg="racket-doc" x-part-tag=""objectprinting"">6.10<tt> </tt><a name="(part._objectprinting)"></a>Object Printing</h4><p>To customize the way that a class instance is printed by
<span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._print%29%29" class="RktValLink" data-pltdoc="x">print</a></span>, <span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._write%29%29" class="RktValLink" data-pltdoc="x">write</a></span> and <span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._display%29%29" class="RktValLink" data-pltdoc="x">display</a></span>, implement the
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fprivate%2Fclass-internal..rkt%29._printable~3c~25~3e%29%29" class="RktValLink" data-pltdoc="x">printable<%></a></span> interface.</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>value</p></div></div><p class="RForeground"><a name="(def._((lib._racket/private/class-internal..rkt)._printable~3c~25~3e))"></a><span title="Provided from: racket/class, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fprivate%2Fclass-internal..rkt%29._printable~3c~25~3e%29%29" class="RktValDef RktValLink" data-pltdoc="x">printable<%></a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym"><a href="objectutils.html#%28def._%28%28lib._racket%2Fprivate%2Fclass-internal..rkt%29._interface~3f%29%29" class="RktValLink" data-pltdoc="x">interface?</a></span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">The <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fprivate%2Fclass-internal..rkt%29._printable~3c~25~3e%29%29" class="RktValLink" data-pltdoc="x">printable<%></a></span> interface includes only the
<span class="RktSym">custom-print</span>, <span class="RktSym">custom-write</span>, and
<span class="RktSym">custom-display</span> methods. The <span class="RktSym">custom-print</span> method
accepts two arguments: the destination port and the current
<span class="RktSym"><a href="quasiquote.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._quasiquote%29%29" class="RktStxLink" data-pltdoc="x">quasiquote</a></span> depth as an exact nonnegative integer. The
<span class="RktSym">custom-write</span> and <span class="RktSym">custom-display</span> methods each accepts
a single argument, which is the destination port to <span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._write%29%29" class="RktValLink" data-pltdoc="x">write</a></span> or
<span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._display%29%29" class="RktValLink" data-pltdoc="x">display</a></span> the object.</div></p><p>Calls to the <span class="RktSym">custom-print</span>, <span class="RktSym">custom-write</span>, or
<span class="RktSym">custom-display</span> methods are like calls to a procedure attached
to a structure type through the <span class="RktSym"><a href="Printer_Extension.html#%28def._%28%28quote._~23~25kernel%29._prop~3acustom-write%29%29" class="RktValLink" data-pltdoc="x">prop:custom-write</a></span>
property. In particular, recursive printing can trigger an escape from
the call.</p><p>See <span class="RktSym"><a href="Printer_Extension.html#%28def._%28%28quote._~23~25kernel%29._prop~3acustom-write%29%29" class="RktValLink" data-pltdoc="x">prop:custom-write</a></span> for more information. The
<span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fprivate%2Fclass-internal..rkt%29._printable~3c~25~3e%29%29" class="RktValLink" data-pltdoc="x">printable<%></a></span> interface is implemented with
<span class="RktSym"><a href="createinterface.html#%28form._%28%28lib._racket%2Fprivate%2Fclass-internal..rkt%29._interface%2A%29%29" class="RktStxLink" data-pltdoc="x">interface*</a></span> and <span class="RktSym"><a href="Printer_Extension.html#%28def._%28%28quote._~23~25kernel%29._prop~3acustom-write%29%29" class="RktValLink" data-pltdoc="x">prop:custom-write</a></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>value</p></div></div><p class="RForeground"><a name="(def._((lib._racket/private/class-internal..rkt)._writable~3c~25~3e))"></a><span title="Provided from: racket/class, racket | Package: base"><span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fprivate%2Fclass-internal..rkt%29._writable~3c~25~3e%29%29" class="RktValDef RktValLink" data-pltdoc="x">writable<%></a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym"><a href="objectutils.html#%28def._%28%28lib._racket%2Fprivate%2Fclass-internal..rkt%29._interface~3f%29%29" class="RktValLink" data-pltdoc="x">interface?</a></span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Like <span class="RktSym"><a href="#%28def._%28%28lib._racket%2Fprivate%2Fclass-internal..rkt%29._printable~3c~25~3e%29%29" class="RktValLink" data-pltdoc="x">printable<%></a></span>, but includes only the
<span class="RktSym">custom-write</span> and <span class="RktSym">custom-display</span> methods.
A <span class="RktSym"><a href="Writing.html#%28def._%28%28quote._~23~25kernel%29._print%29%29" class="RktValLink" data-pltdoc="x">print</a></span> request is directed to <span class="RktSym">custom-write</span>.</div></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, "6.7", "../");" 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("6.7");">top</a></span><span class="navright"> <a href="objectserialize.html" title="backward to "6.9 Object Serialization"" data-pltdoc="x">← prev</a> <a href="mzlib_class.html" title="up to "6 Classes and Objects"" data-pltdoc="x">up</a> <a href="objectutils.html" title="forward to "6.11 Object, Class, and Interface Utilities"" data-pltdoc="x">next →</a></span> </div></div></div><div id="contextindicator"> </div></body></html>
|