m stack at run time. In earlier releases recursive
function calls could use a great deal of stack, and this could cause problems,
but this usage has been eliminated. Backtracking positions are now explicitly
remembered in memory frames controlled by the code.
</P>
<P>
The size of each frame depends on the size of pointer variables and the number
of capturing parenthesized groups in the pattern being matched. On a 64-bit
system the frame size for a pattern with no captures is 128 bytes. For each
capturing gr