[R] using bquote to construct function

[Sundar Dorai-Raj]

Thanks, Gabor! This workaround fixes my immediate needs.

--sundar

Gabor Grothendieck said the following on 10/1/2008 10:42 PM:
> That may be a bug in R but I think there is another problem on top of that
> as I don't think bquote descends into function bodies:
> 
>> z <- 2
>> bquote(function(x) {x^.(z)})
> function(x) {x^.(z)}
> 
>> bquote(function(x, y) { x^.(z) + y})
> function(x, y) { x^.(z) + y}
> 
>> R.version.string # Vista
> [1] "R version 2.7.2 (2008-08-25)"
> 
> Try it this way:
> 
> z <- 2
> f <- function(x, y) {}
> body(f) <- bquote({ x^.(z) + y })
> eval(f)(2, 3)
> 
> On Thu, Oct 2, 2008 at 1:14 AM, Sundar Dorai-Raj
> <sundar.dorai-raj at pdf.com> wrote:
>> Hi, R-help,
>>
>> (sessionInfo at the end)
>>
>> I'm trying to construct a function using bquote and running into a strange
>> error message. As an example, what I would like to do is this:
>>
>> z <- 2
>> eval(bquote(function(x, y) { x^.(z) + y }))(2, 3)
>>
>> However, I get the following:
>>
>> Error in eval(expr, envir, enclos) :
>>  invalid formal argument list for "function"
>>
>> However, if I change the command to following, it works:
>>
>> z <- 2
>> eval(bquote(function(x) { x^.(z) }))(2)
>> # [1] 4
>>
>> In other words, I remove the second argument. Is there a workaround for this
>> without using eval(parse(text = ))?
>>
>> Thanks,
>>
>> --sundar
>>
>>> sessionInfo()
>> R version 2.7.2 (2008-08-25)
>> i386-pc-mingw32
>>
>> locale:
>> LC_COLLATE=English_United States.1252;LC_CTYPE=English_United
>> States.1252;LC_MONETARY=English_United
>> States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252
>>
>> attached base packages:
>> [1] stats     graphics  grDevices utils     datasets  methods   base
>>
>> ______________________________________________
>> R-help at r-project.org 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.
>>
> 
> ______________________________________________
> R-help at r-project.org 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.