<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd"> <HTML> <HEAD> <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <META name="GENERATOR" content="hevea 1.06-7 of 2001-11-14"> <TITLE> Debugging messages </TITLE> </HEAD> <BODY TEXT=black BGCOLOR=white> <A HREF="manual012.html"><IMG SRC ="previous_motif.gif" ALT="Previous"></A> <A HREF="manual009.html"><IMG SRC ="contents_motif.gif" ALT="Contents"></A> <A HREF="manual014.html"><IMG SRC ="next_motif.gif" ALT="Next"></A> <HR> <TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#66dbff"><DIV ALIGN=center><TABLE> <TR><TD><FONT SIZE=4><B><A NAME="htoc26">4.4</A></B></FONT></TD> <TD WIDTH="100%" ALIGN=center><FONT SIZE=4><B>Debugging messages</B></FONT></TD> </TR></TABLE></DIV></TD> </TR></TABLE> We here described which information is displayed by the debugger when it shows a goal. The basic format is as follows: <DL COMPACT=compact><DT><DD><TT><I>S N M Port</I>: <I>Goal</I> ?</TT></DL><I><TT> S</TT></I> is a spy-point indicator: if there is a spy-point on the current goal the <TT>+</TT> symbol is displayed else a space is displayed. <I><TT>N</TT></I> is the invocation number. This unique number can be used to correlate the trace messages for the various ports, since it is unique for every invocation. <I><TT>M</TT></I> is an index number which represents the number of direct ancestors of the goal (i.e. the current depth of the goal). <I><TT>Port</TT></I> specifies the particular port (<TT>call</TT>, <TT>exit</TT>, <TT>fail</TT>, <TT>redo</TT>, <TT>exception</TT>). <I><TT>Goal</TT></I> is the current goal (it is then possible to inspect its current instantiation) which is displayed using <TT>write_term/3</TT> with <TT>quoted(true)</TT> and <TT>max_depth(<I>D</I>)</TT> options (section <A HREF="manual037.html#write-term/3">7.14.6</A>). Initially <I><TT>D</TT></I> (the print depth) is set to 10 but can be redefined using the <TT><</TT> debugger command (section <A HREF="manual014.html#Debugger-commands">4.5</A>). The <TT>?</TT> symbol is displayed when the debugger is waiting a command from the user. (i.e. <TT>Port</TT> is a leashed port). If the port is unleashed, this symbol is not displayed and the debugger continues the execution displaying the next goal.<BR> <BR> <HR SIZE=2> Copyright (C) 1999-2002 Daniel Diaz <BR> <BR> Verbatim copying and distribution of this entire article is permitted in any medium, provided this notice is preserved. <BR> <BR> <A HREF="index.html#copyright">More about the copyright</A> <HR> <A HREF="manual012.html"><IMG SRC ="previous_motif.gif" ALT="Previous"></A> <A HREF="manual009.html"><IMG SRC ="contents_motif.gif" ALT="Contents"></A> <A HREF="manual014.html"><IMG SRC ="next_motif.gif" ALT="Next"></A> </BODY> </HTML>