There are many occasions where an array's internal pointer gets modifed by a function that requires a traversal for one reason or another (e.g., foreach, array_walk, etc.). This often messes with the continuity and readability of the code. For example, some sort of a workaround is required if one wants to nest a foreach statement within another operating on the same array. Often these workarounds involve various traversals or copy operations and can cause serious performance issues with larger array.

A simple solution for this is to provide for an internal pointer stack. I propose two functions:

void pos_push(array array);
mixed pos_pop(array array);

The function pos_push merely pushes the internal pointer position onto the pointer stack. The complementary function pos_pop pops the internal pointer off of the stack and returns the resulting current value of the new position in the array.

This is easy to efficiently implement through a linked list stack specific to each array. The memory usage is minimal, and overhead is slight. The stack could store the actual position pointers. Of course, that means care would have to be taken if an element that was been stored on the stack was deleted.