[Rd] Syntactically valid names

peter dalgaard pdalgd at gmail.com
Wed Jul 6 02:22:04 CEST 2011


On Jul 6, 2011, at 01:40 , Hadley Wickham wrote:

> On Tue, Jul 5, 2011 at 7:31 PM, steven mosher <moshersteven at gmail.com> wrote:
>>  regexp approach is kinda ugly
>> http://www.r-bloggers.com/testing-for-valid-variable-names/
> 
> Hmm, I think that suggests a couple of small bug in make.names:
> 
>> make.names("...")
> [1] "..."
>> make.names("..1")
> [1] "..1"
> 

What's wrong with that? They are names alright, just with special meanings.

> x <- quote(...)
> mode(x)
[1] "name"


> and
> 
>> x <- paste(rep("x", 1e6), collapse = "")
>> x == make.names(x)
> [1] TRUE
> 
> 

Mildly insane, but technically OK, no?


> Hadley
> 
> -- 
> Assistant Professor / Dobelman Family Junior Chair
> Department of Statistics / Rice University
> http://had.co.nz/

-- 
Peter Dalgaard
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com



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