.SETITEM index array value

Change the indexth item of array to be value. This similar to SETITEM, except that it does not check for circularity.

WARNING: Primitives whose names start with a period are dangerous. Their use by non-experts is not recommended. The use of .SETITEM can lead to circular array structures, which can lead to very unintuitive behavior.

MAKE "myarray (ARRAY 3 0)
.SETITEM 2 :myarray 1
.SETITEM 1 :myarray 2
.SETITEM 0 :myarray 3
SHOW :myarray
{3 2 1}