PHP Array Map class: Manipulate arrays in a memory efficient way

This package can manipulate arrays in a memory efficient way.

It provides classes implement the interfaces so its objects can be manipulate like regular array values, but internally elements are stored in memory efficient ways.

Two special array element storage modes use SplFixedArray to optimize arrays using a pre-defined size, and in the binary mode it uses PHP memory stream wrapper to store array elements as compact memory entries.