[R-SIG-Finance] FinancialInstrument functions output / side effect variables

[Doug Edmunds]

How can I see what the names of variables and what is being stored
in them when running functions in the FinancialInstrument package?  I am 
using R-Studio.

For example, running:
 > currency("USD")
outputs this to the console window:
[1] "USD"

but gives me no clue as to where that value is being
stored or how to access it.

Similarly, reading a tutorial such as:

http://blog.fosstrading.com/2011/07/creating-financial-instrument-metadata.html, 
it says:

"build_series_symbols returns a vector of series symbols that we could 
use to request data or create future_series instruments."

But what is the name of the vector?  Where is it stored?

Thanks.