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marked to <B>NOT</B> point to another Judy array. A <B>JLAP_INVALID</B> flag is 
used in the least significant bit(s) of the pointer.  
After the flag <B>JLAP_INVALID</B> is removed, it is used as a pointer to the users data.
The <B>Judy.h</B> header file defines <B>JLAP_INVALID</B>.
See code fragment below.
<P>
Note: The current version of <B>Judy.h</B> changed this flag from 0x4 to 0x1 
to allow for a <I>malloc()</I> that does not deliver memory on an 8 byte 
aligned boundry (such as old versions of valgrind).
<P>
The following example code segment can be used to determine whether or
not a pointer points to another JudyL:
<P>
<PRE>
PValue = (PWord_t)PMultiDimArray;

for (Dim = 0; ;Dim++)
{
   if (PValue == (PWord_t)NULL) goto IndexNotFound;

   /* Advance to next dimension in array */
   JLG(PValue, (Pvoid_t)*PValue, Index[Dim]);

   /* Check if pointer to user buffer: */
   if (*PValue &amp; JLAP_INVALID)) break;
}
UPointer = (UPointer_t) (*PValue &amp; ~JLAP_INVALID);  // mask and cast.
printf("User object pointer is 0x%lx\n", (Word_t) UPointer);
       ...
</PRE>
<P>
Note:  This works because <I>malloc()</I> guarantees to return a pointer
with the least bit(s) == 0x0.
You must remove <B>JLAP_INVALID</B> before using the pointer.
</DL>
<!----------------->
<P>
<DT><A name="JLERR"><B>ERRORS:</B> See: </A><A href="Judy_3.htm#ERRORS">Judy_3.htm#ERRORS</A></DT>
<DD>
<!----------------->
<P>
<DT><B>EXAMPLE</B></DT>
<DD>
Read a series of index/value pairs from the standard input, store
in a JudyL array, and then print out in sorted order.
<P>
<PRE>
#include &lt;stdio.h&gt;
#include &lt;Judy.h&gt;

Word_t   Index;                     // array index
Word_t   Value;                     // array element value
Word_t * PValue;                    // pointer to array element value
int      Rc_int;                    // return code

Pvoid_t  PJLArray = (Pvoid_t) NULL; // initialize JudyL array

while (scanf("%lu %lu", &amp;Index, &amp;Value))
{
    JLI(PValue, PJLArray, Index);
    If (PValue == PJERR) goto process_malloc_failure;
    *PValue = Value;                 // store new value
}
// Next, visit all the stored indexes in sorted order, first ascending,
// then descending, and delete each index during the descending pass.

Index = 0;
JLF(PValue, PJLArray, Index);
while (PValue != NULL)
{
    printf("%lu %lu\n", Index, *PValue));
    JLN(PValue, PJLArray, Index);
}

Index = -1;
JLL(PValue, PJLArray, Index);
while (PValue != NULL)
{
    printf("%lu %lu\n", Index, *PValue));

    JLD(Rc_int, PJLArray, Index);
    if (Rc_int == JERR) goto process_malloc_failure;

    JLP(PValue, PJLArray, Index);
}
</PRE>
<!----------------->
<P>
<DT><B>AUTHOR</B></DT>
<DD>
Judy was invented by Doug Baskins and implemented by Hewlett-Packard.
<!----------------->
<P>
<DT><B>SEE ALSO</B></DT>
<DD>
<A href="Judy_3.htm">Judy(3)</A>,
<A href="Judy1_3.htm">Judy1(3)</A>,
<A href="JudySL_3.htm">JudySL(3)</A>,
<A href="JudyHS_3.htm">JudyHS(3)</A>,
<BR>
<I>malloc()</I>,
<BR>
<A href="http://judy.sourceforge.net">
http://judy.sourceforge.net</A>,
for more information and Application Notes.
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