[R] backticks

[Peter Dalgaard]

Robin Hankin wrote:
> Peter
>
> Aha!  so R backticks work just like bash backticks  (duh!)
>   

Er, no. Backticks in shells have a command inside that will be evaluated
and replaced by its output. (This is a bit confusing, but single and
double quotes were already taken at the time...)

> unless they are on the LHS of an assignment.
>
> [We bash people now use $(...) instead]
>
> Could we add something to this effect to Quotes.Rd?
>
>
> rksh
>
>
> On 4 Dec 2006, at 14:33, Peter Dalgaard wrote:
>
>   
>> Robin Hankin wrote:
>>     
> [snip]
>   
>>> What exactly do backticks do that single or double quotes don't?
>>>
>>>       
>> I don't know whether we really want to be that dogmatic about it,  
>> but in
>> a nutshell
>>
>> `like this` <- 2
>> "like that" <- 3
>> print(`like this`)
>> print("like that")
>>
>> I.e. backtick'ed names work whereever ordinary names do, but quoted
>> names work only on the LHS of assignments.
>>
>> The note in ?formula should probably be understood defensively: We
>> intend backtick'ed names to work in all contexts, but  there may be
>> programming practices where the backticks are not preserved  
>> (notably if
>> there is a deparse-reparse step involved).
>>
>>     
>>> Where do I look for documentation on this?
>>>
>>>
>>>
>>>
>>> --
>>> Robin Hankin
>>> Uncertainty Analyst
>>> National Oceanography Centre, Southampton
>>> European Way, Southampton SO14 3ZH, UK
>>>   tel  023-8059-7743
>>>
>>> ______________________________________________
>>> R-help at stat.math.ethz.ch mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide http://www.R-project.org/posting- 
>>> guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>>       
>> -- 
>>    O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
>>   c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
>>  (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45)  
>> 35327918
>> ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45)  
>> 35327907
>>     
>
> --
> Robin Hankin
> Uncertainty Analyst
> National Oceanography Centre, Southampton
> European Way, Southampton SO14 3ZH, UK
>   tel  023-8059-7743
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>   


-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907