IsNull/ahkDBA — pull request #9 by infogulch (2012-06-01 05:28:41+00:00)
Title: Fix performance issue in Collections.Count()

This originally looped through the entire object to get the number of
items. For large objects, this could be a huge performance hit. Instead,
use `this.SetCapacity(0)`, which returns the object's capacity after
shrinking the object to fit. Any performance loss due to shrinking the
object prematurely is gained back exponentially by removing a loop of ahk
code.

Think:

while this.Count() < 1000000
this.insert(A_Index)

This code would loop 1000000*500000 times before this commit. Insane.