kdb q Assign Error

Assign errors happen when you attempt to assign a new value to a built-in kdb function.

q)asc
k){$[99h=@x;(!x)[i]!`s#r i:<r:. x;`s=-2!x;x;0h>@x;'`rank;`s#x@<x]}
q)asc:{x}
'assign

q).Q.fc
k){[f;x]$[(#x)&1<n:"j"$."\\s";,/f':(n;0N)#x;f x]}
q).Q.fc:{ x;y}

Notice I cannot assign a new value to asc as it's a reserved word. I can however reassign the value of functions in the .Q namespace that kdb provides. On the rare occasion kx add a new function, e.g. they added ema (exponential moving average) as a built-in, this can break existing code if anyone had added their own ema function.

See Also