Yes, for some languages shift may mean returning an element. But in Nim we have shl and shr operators. scroll may be confused with rotation?
I will look at your code in more detail tonigth -- you are using magic reset proc from system module. I tried also a year ago, then I asked Araq in IRC about the comment "This needs to be called before any possible object branch transition." in the docs. He just told me I should not use it if I do not understand purpose, so I removed that proc from my code.
