Looks like there are cases when creation of empty-symbol fails.
I found a case when (bra data.table nil something) throws an exception about missing value.
The root of a problem lays with the fact that empty symbol cannot be assigned to a value (http://adv-r.had.co.nz/Expressions.html#names). When we evaluate something it's always assigned to a value.
What seems to work perfectly is artificial RObject:
Looks like there are cases when creation of empty-symbol fails.
I found a case when (bra data.table nil something) throws an exception about missing value.
The root of a problem lays with the fact that empty symbol cannot be assigned to a value (http://adv-r.had.co.nz/Expressions.html#names). When we evaluate something it's always assigned to a value.
What seems to work perfectly is artificial RObject:
That means to we have to have special case for RObject recreation during session change. When we set code to
nil
they should stay untouched.