<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <!-- $Id: strict.html 1823 2007-12-28 13:43:03Z deraugla $ --> <!-- Copyright (c) 2007-2008 INRIA --> <title>Camlp5</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta http-equiv="Content-Style-Type" content="text/css" /> <link rel="stylesheet" type="text/css" href="styles/base.css" title="Normal" /> <link rel="alternate" type="application/rss+xml" href="rss/camlp5.rss" title="Camlp5"/> </head> <body> <div id="menu"> <h1>- <a href="http://pauillac.inria.fr/~ddr/camlp5">Camlp5</a> -</h1> <p class="subtitle">Version 5.11</p> <ul> <li><a href="index.html">Introduction</a></li> <li><a href="strict.html">Transitional and Strict</a></li> <li><a href="ptools.html">Parsing and printing tools</a></li> </ul> <ul> <li>Parsing tools <ul> <li><a href="parsers.html">Stream parsers</a></li> <li><a href="lexers.html">Stream lexers</a></li> <li><a href="fparsers.html">Functional parsers</a></li> <li><a href="bparsers.html">Backtracking parsers</a></li> <li><a href="grammars.html">Extensible grammars</a></li> </ul> </li> <li>Printing tools <ul> <li><a href="printers.html">Extensible printers</a></li> <li><a href="pprintf.html">Pprintf</a></li> <li><a href="pretty.html">Pretty print</a></li> </ul> </li> <li>Language extensions <ul> <li><a href="locations.html">Locations</a></li> <li><a href="ml_ast.html">Syntax tree</a></li> <li><a href="ast_transi.html">Syntax tree - transi</a></li> <li><a href="ast_strict.html">Syntax tree - strict</a></li> <li><a href="q_ast.html">Quotation kit q_ast.cmo</a></li> <li><a href="pcaml.html">The Pcaml module</a></li> <li><a href="syntext.html">Extensions of syntax</a></li> <li><a href="opretty.html">Extensions of printing</a></li> <li><a href="quot.html">Quotations</a></li> <li><a href="revsynt.html">Revised syntax</a></li> <li><a href="scheme.html">Scheme syntax</a></li> <li><a href="macros.html">Macros</a></li> <li><a href="pragma.html">Pragma directive</a></li> <li><a href="extfun.html">Extensible functions</a></li> </ul> </li> <li>Appendix <ul> <li><a href="commands.html">Commands and Files</a></li> <li><a href="library.html">Library</a></li> <li><a href="sources.html">Camlp5 sources</a></li> <li><a href="about.html">About Camlp5</a></li> </ul> </li> </ul> </div> <div id="content"> <h1 class="top">Transitional and Strict modes</h1> <p>Since version 5.00, Camlp5 has been able to be installed in two modes: the <em>transitional</em> mode and the <em>strict</em> mode. When Camlp5 is installed, it works with one only of these modes (the two modes contain indeed different definitions of some interfaces and are incompatible with one another). The user must choose in which mode he wants to use Camlp5.</p> <p>This notion has been introduced to ensure backward compatibility of the Camlp5 syntax tree, together with the usage of a new quotation kit "<tt>q_ast.cmo</tt>", which allows to use Camlp5 syntax tree quotations in user syntax (with all its possible extensions).</p> <dl style="font-size:80%; font-style:oblique"> <dt>A short example of these syntax tree quotations:</dt> <dd> <p>If the syntax of the <a href="grammars.html">extensible grammars</a> has been added, it is possible to write things like:</p> <pre> <:expr< EXTEND a: [ [ c = d -> $e$ ] ]; END >>; </pre> <p>representing the syntax tree of this statement: this is not possible with the classical quotation kit "<tt>q_MLast.cmo</tt>" because all quotations must be there only in <a href="revsynt.html">revised syntax</a> and without syntax extensions.</p> </dd> </dl> <p>Here are the differences between the two modes:</p> <dl> <dt>Transitional</dt> <dd> <dl> <dt>Compatibility</dt> <dd>The syntax tree is fully compatible with the previous versions of Camlp5, no changes has to be done in the users' programs.</dd> <dt>Quotation kit "<tt>q_ast.cmo</tt>"</dt> <dd>The antiquotations are not available: when used, a syntax error message is displayed.</dd> </dl> </dd> <dt>Strict</dt> <dd> <dl> <dt>Compatibility</dt> <dd>The syntax tree is different, users' programs may have to be modified, but not necessarily.</dd> <dt>Quotation kit "<tt>q_ast.cmo</tt>"</dt> <dd>All antiquotations are available.</dd> </dl> </dd> </dl> <p>In strict mode, the programs have more chances to be compatible with the previous versions if they use syntax tree quotations rather than syntax tree nodes. A solution is therefore to change the expressions and patterns using nodes into expressions and patterns using quotations (which is backward compatible).</p> <h2 id="a:Which-mode-is-installed--">Which mode is installed ?</h2> <p>To determine the mode of an installed version of Camlp5, type:</p> <pre> camlp5 -pmode </pre> <h2 id="a:Selecting-mode-when-compiling-Camlp5">Selecting mode when compiling Camlp5</h2> <p>When compiling Camlp5 from source, the mode must first be selected at configuration time. The <em>configure</em> script must be run with one of these options:</p> <pre> ./configure -strict ./configure -transitional </pre> <p>The default is "transitional", i.e. without option, the sources are compiled in transitional mode.</p> <a class="toplink" href="strict.html">↑</a> <div class="trailer"> <hr style="margin:0" /><div style="font-size: 80%"><em>Copyright 2007 Daniel de Rauglaudre (INRIA)</em></div> <p class="bottom"> <a href="http://validator.w3.org/check?uri=referer"><img src="images/valid-xhtml11.png" style="border:0" alt="Valid XHTML 1.1" height="31" width="88" /></a> </p> </div> </div> </body> </html>