[R] Creating unary operators

McGehee, Robert
Fri, 07 Jan 2005 21:25:51 -0000

Is it correct (by its lack of mention in the R-Language Definition
Manual) that it is impossible to create a user-defined unary operator?

Ex: (This doesn't work, but it's an example of what I'm looking for)

> "%PLUSONE%" <- function(x) x + 1
> %PLUSONE% 2
[1] 3

And if the above is impossible, am I limited to only the + - ~ ! unary
operators for overloading?

On the same vein, is it correct that "[" and "[[" are the
only possible
indexing generics? (Assigning "[" to "[[[" doesn't seem
to work, and
nothing else is mentioned in the manual)

My goal is to parse well-defined character strings into R-readable code,
while preserving the structure of this text-language as much as
possible, so I'd rather compute on the R language rather than on this
text language.

Best,
Robert

Robert McGehee
Geode Capital Management, LLC
53 State Street, 5th Floor | Boston, MA | 02109
Tel: 617/392-8396    Fax:617/476-6389
mailto:robert.mcgehee at geodecapital.com



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