[R] Limitations on R code file

[guox at ucalgary.ca]

I would like to run R code from a file that is generated from other source.
The file consists of some variables and formulas/equations such as

Variables = log(100)
##Other variable definitions
VariablesWithLongNames = 2*3*log(12345678)+10^4 + Variables
Equations=log(VariablesWithLongNames)+Variables^2
##Other equations, formulas
Result = Equations^2+rnorm(10000)
hist(Result,breaks=100,freq=FALSE)
lines(density(Result),col = "blue")

The file may be very long and some variable names may be very long too.
We know that objects > 100Mb can cause R to run out of memory. Not sure
if there are any other limitations on variable length and source file length.
So my question is

what are the limitations of variable name length and the source file length
in R?

Could you please drop a few lines or point me know where I can find them?
Thanks,

-james