Hi,

Right now, in my R project, I have functions1.R with doFoo() and doBar(), functions2.R with other functions, and main.R with the main program in it, which first does source('functions1.R'); source('functions2.R'), and then calls the other functions.

I've been starting the program from the R GUI in Mac OS X, with source('main.R'). This is fine the first time, but after that, the variables that were defined the first time through the program are defined for the second time functions*.R are sourced, and so the functions get a whole bunch of extra variables defined.

I don't want that! I want an "undefined variable" error when my function uses a variable it shouldn't! Twice this has given me very late nights of debugging!

So how do other people deal with this sort of problem? Is there something like source(), but that makes an independent namespace that doesn't fall through to the main one? Making a package seems like one solution, but it seems like a big pain in the butt compared to e.g. Python, where a source file is automatically a separate namespace.

Any tips? Thank you!