change vs ←@ in LOOPS methods

[pamoroso]

Consider the code of LOOPS method Window.AfterMove:

Why does it call change instead of ←@ for changing the value of instance variables? Is this just an idiom or there's a reason for not using ←@?

[masinter]

you'd have to ask smL (Stan Lanning), but my guess is "legibility". Change, like cl:setf, can be used with many different location types.

[pamoroso]

The LOOPS manual seems to confirm this:

This uniform interface allows simpler expressions for changes, and arbitrary extensions through Changetran.