[Rd] The default behaviour of a missing entry in an environment

Trishank Karthik Kuppusamy tk47 at nyu.edu
Fri Nov 13 20:39:41 CET 2009


Hello Duncan,

Thanks for your reply.

On Nov 13, 2009, at 2:27 PM, Duncan Murdoch wrote:

> You get the same behaviour when asking for a nonexistent element of a list, or a nonexistent attribute.   If you want stricter checking, don't use $, use get():
> 
> > get("b", e)
> Error in get("b", e) : object 'b' not found

Yes, this is a solution. However, if we agree that "$" is (as it should be) syntactic sugar for get(), then why do we have different behaviour
for what should essentially be the same operations, albeit the former being easier to read and write than the latter?
Or is my premise mistaken and that is the whole point of having "$" and get() which are not identical?

> But then it would be inconsistent with what it does in other situations.

I am afraid that I did not fully understand this point. What would the inconsistencies be in other situations?

-Trishank


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