Exclamation marks reserved for mutating functions

[calder]

From the manual:

Julia has several functions that can mutate their arguments. For example, it has sort(v) and sort!(v).

[milktrader]

This package needs a complete overhaul. One issue is that yahoo and fred methods should probably not be exported but users should use the Quandl package. That package is awaiting a consistent time-aware Dataframe as well as a readtable method that accepts http addresses.

But anyway, thanks for the correction. I forgot all about that function.