<HTML> <HEAD> <!-- Created by texi2html 1.56k + clip patches and <A href="http://www.clip.dia.fi.upm.es/Software">lpdoc</A> from ciao.texi on 28 January 2007 --> <LINK rel="stylesheet" href="ciao.css" type="text/css"> <TITLE>The Ciao Prolog System - Miscellaneous predicates</TITLE> </HEAD> <BODY> Go to the <A HREF="ciao_1.html">first</A>, <A HREF="ciao_104.html">previous</A>, <A HREF="ciao_106.html">next</A>, <A HREF="ciao_241.html">last</A> section, <A HREF="ciao_toc.html">table of contents</A>. <P><HR><P> <H1><A NAME="SEC436" HREF="ciao_toc.html#TOC436">Miscellaneous predicates</A></H1> <P> <A NAME="IDX5390"></A> <P> <STRONG>Author(s):</STRONG> Manuel Carro, Daniel Cabeza. <P> <STRONG>Version:</STRONG> 1.10#7 (2006/4/26, 19:22:13 CEST) <P> <STRONG>Version of last change:</STRONG> 1.3#95 (1999/11/8, 18:37:30 MET) <P> This module implements some miscellaneous non-logical (but sometimes very useful) predicates. <UL> <LI><A HREF="ciao_105.html#SEC437">Usage and interface (odd)</A> <LI><A HREF="ciao_105.html#SEC438">Documentation on exports (odd)</A> </UL> <H2><A NAME="SEC437" HREF="ciao_toc.html#TOC437">Usage and interface (<CODE>odd</CODE>)</A></H2> <div class="cartouche"> <UL> <LI><STRONG>Library usage:</STRONG> <CODE>:- use_module(library(odd)).</CODE> <LI><STRONG>Exports:</STRONG> <UL> <LI><EM>Predicates:</EM> <A NAME="IDX5391"></A> <CODE>setarg/3</CODE>, <A NAME="IDX5392"></A> <CODE>undo/1</CODE>. </UL> </UL> </div class="cartouche"> <H2><A NAME="SEC438" HREF="ciao_toc.html#TOC438">Documentation on exports (<CODE>odd</CODE>)</A></H2> <P> <A NAME="IDX5393"></A> <A NAME="IDX5394"></A> <DL> <DT><span class="define">PREDICATE:</span> <B>setarg/3:</B> <DD><A NAME="IDX5395"></A> <P> <STRONG>Usage:</STRONG> <CODE>setarg(Index, Term, NewArg)</CODE> <UL> <LI><EM>Description:</EM> Replace destructively argument <CODE>Index</CODE> in <CODE>Term</CODE> by <CODE>NewArg</CODE>. The assignment is undone on backtracking. This is a major change to the normal behavior of data assignment in Ciao Prolog. <LI><EM>The following properties should hold at call time:</EM> <CODE>Index</CODE> is currently instantiated to an integer. (<CODE>term_typing:integer/1</CODE>) <CODE>Term</CODE> is a compound term. (<CODE>basic_props:struct/1</CODE>) <CODE>NewArg</CODE> is any term. (<CODE>basic_props:term/1</CODE>) <LI><EM>The following properties hold upon exit:</EM> <CODE>Index</CODE> is currently instantiated to an integer. (<CODE>term_typing:integer/1</CODE>) <CODE>Term</CODE> is a compound term. (<CODE>basic_props:struct/1</CODE>) <CODE>NewArg</CODE> is any term. (<CODE>basic_props:term/1</CODE>) </UL> </DL> <P> <A NAME="IDX5396"></A> <A NAME="IDX5397"></A> <DL> <DT><span class="define">PREDICATE:</span> <B>undo/1:</B> <DD><A NAME="IDX5398"></A> <P> <EM>Meta-predicate</EM> with arguments: <CODE>undo(goal)</CODE>. <P> <STRONG>Usage:</STRONG> <CODE>undo(Goal)</CODE> <UL> <LI><EM>Description:</EM> <CODE>call(<CODE>Goal</CODE>)</CODE> is executed on backtracking. This is a major change to the normal <A NAME="IDX5399"></A> control of Ciao Prolog execution. <LI><EM>The following properties should hold at call time:</EM> <CODE>Goal</CODE> is a term which represents a goal, i.e., an atom or a structure. (<CODE>basic_props:callable/1</CODE>) <LI><EM>The following properties hold upon exit:</EM> <CODE>Goal</CODE> is a term which represents a goal, i.e., an atom or a structure. (<CODE>basic_props:callable/1</CODE>) </UL> </DL> <P><HR><P> Go to the <A HREF="ciao_1.html">first</A>, <A HREF="ciao_104.html">previous</A>, <A HREF="ciao_106.html">next</A>, <A HREF="ciao_241.html">last</A> section, <A HREF="ciao_toc.html">table of contents</A>. </BODY> </HTML>
