* ref3.tex: added cross-ref to try statement for exc handler.

* ref7.tex: added description of sys.exc_{type,value,traceback}.
* lib5.tex: rect.intersect is different now!

Doc/ref/ref3.tex

@@ -532,12 +532,13 @@ the code object).
 \ttindex{f_lineno}
 \ttindex{f_lasti}
 
-\item[Traceback objects]
+\item[Traceback objects] \label{traceback}
 Traceback objects represent a stack trace of an exception.  A
 traceback object is created when an exception occurs.  When the search
 for an exception handler unwinds the execution stack, at each unwound
 level a traceback object is inserted in front of the current
-traceback.  When an exception handler is entered, the stack trace is
+traceback.  When an exception handler is entered
+(see also section \ref{try}), the stack trace is
 made available to the program as \verb\sys.exc_traceback\.  When the
 program contains no suitable handler, the stack trace is written
 (nicely formatted) to the standard error stream; if the interpreter is

Doc/ref/ref7.tex

@@ -172,7 +172,7 @@ for x in a[:]:
     if x < 0: a.remove(x)
 \end{verbatim}
 
-\section{The {\tt try} statement}
+\section{The {\tt try} statement} \label{try}
 \stindex{try}
 
 The \verb\try\ statement specifies exception handlers and/or cleanup
@@ -222,6 +222,19 @@ statement.  (This means that if two nested handlers exist for the same
 exception, and the exception occurs in the try clause of the inner
 handler, the outer handler will not handle the exception.)
 
+Before an except clause's suite is executed, details about the
+exception are assigned to three variables in the \verb\sys\ module:
+\verb\sys.exc_type\ receives the object identifying the exception;
+\verb\sys.exc_value\ receives the exception's parameter;
+\verb\sys.exc_traceback\ receives a traceback object (see section
+\ref{traceback}) identifying the point in the program where the
+exception occurred.
+\bimodindex{sys}
+\ttindex{exc_type}
+\ttindex{exc_value}
+\ttindex{exc_traceback}
+\obindex{traceback}
+
 The \verb\try...finally\ form specifies a `cleanup' handler.  The
 \verb\try\ clause is executed.  When no exception occurs, the
 \verb\finally\ clause is executed.  When an exception occurs in the

Doc/ref3.tex

@@ -532,12 +532,13 @@ the code object).
 \ttindex{f_lineno}
 \ttindex{f_lasti}
 
-\item[Traceback objects]
+\item[Traceback objects] \label{traceback}
 Traceback objects represent a stack trace of an exception.  A
 traceback object is created when an exception occurs.  When the search
 for an exception handler unwinds the execution stack, at each unwound
 level a traceback object is inserted in front of the current
-traceback.  When an exception handler is entered, the stack trace is
+traceback.  When an exception handler is entered
+(see also section \ref{try}), the stack trace is
 made available to the program as \verb\sys.exc_traceback\.  When the
 program contains no suitable handler, the stack trace is written
 (nicely formatted) to the standard error stream; if the interpreter is

Doc/ref7.tex

@@ -172,7 +172,7 @@ for x in a[:]:
     if x < 0: a.remove(x)
 \end{verbatim}
 
-\section{The {\tt try} statement}
+\section{The {\tt try} statement} \label{try}
 \stindex{try}
 
 The \verb\try\ statement specifies exception handlers and/or cleanup
@@ -222,6 +222,19 @@ statement.  (This means that if two nested handlers exist for the same
 exception, and the exception occurs in the try clause of the inner
 handler, the outer handler will not handle the exception.)
 
+Before an except clause's suite is executed, details about the
+exception are assigned to three variables in the \verb\sys\ module:
+\verb\sys.exc_type\ receives the object identifying the exception;
+\verb\sys.exc_value\ receives the exception's parameter;
+\verb\sys.exc_traceback\ receives a traceback object (see section
+\ref{traceback}) identifying the point in the program where the
+exception occurred.
+\bimodindex{sys}
+\ttindex{exc_type}
+\ttindex{exc_value}
+\ttindex{exc_traceback}
+\obindex{traceback}
+
 The \verb\try...finally\ form specifies a `cleanup' handler.  The
 \verb\try\ clause is executed.  When no exception occurs, the
 \verb\finally\ clause is executed.  When an exception occurs in the