[Rd] substitute() on arguments in ellipsis ("dot dot dot")?

2018-08-12 Thread Henrik Bengtsson 
Hi. For any number of *known* arguments, we can do:

one <- function(a) list(a = substitute(a))
two <- function(a, b) list(a = substitute(a), b = substitute(b))

and so on. But how do I achieve the same when I have:

dots <- function(...) list(???)

I want to implement this such that I can do:

> exprs <- dots(1+2)
> str(exprs)
List of 1
 $ : language 1 + 2

as well as:

> exprs <- dots(1+2, "a", rnorm(3))
> str(exprs)
List of 3
 $ : language 1 + 2
 $ : chr "a"
 $ : language rnorm(3)

Is this possible to achieve using plain R code?

Thanks,

Henrik

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Re: [Rd] substitute() on arguments in ellipsis ("dot dot dot")?

2018-08-12 Thread Duncan Murdoch 

On 12/08/2018 4:00 PM, Henrik Bengtsson wrote:

Hi. For any number of *known* arguments, we can do:

one <- function(a) list(a = substitute(a))
two <- function(a, b) list(a = substitute(a), b = substitute(b))

and so on. But how do I achieve the same when I have:

dots <- function(...) list(???)

I want to implement this such that I can do:


exprs <- dots(1+2)
str(exprs)

List of 1
  $ : language 1 + 2

as well as:


exprs <- dots(1+2, "a", rnorm(3))
str(exprs)

List of 3
  $ : language 1 + 2
  $ : chr "a"
  $ : language rnorm(3)

Is this possible to achieve using plain R code?


I think so.  substitute(list(...)) gives you a single expression 
containing a call to list() with the unevaluated arguments; you can 
convert that to what you want using something like


dots <- function (...) {
  exprs <- substitute(list(...))
  as.list(exprs[-1])
}

Duncan Murdoch

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Re: [Rd] substitute() on arguments in ellipsis ("dot dot dot")?

2018-08-12 Thread Jeroen Ooms 
On Sun, Aug 12, 2018 at 10:00 PM, Henrik Bengtsson
 wrote:
> Hi. For any number of *known* arguments, we can do:
>
> one <- function(a) list(a = substitute(a))
> two <- function(a, b) list(a = substitute(a), b = substitute(b))
>
> and so on. But how do I achieve the same when I have:
>
> dots <- function(...) list(???)
>
> I want to implement this such that I can do:
>
>> exprs <- dots(1+2)
>> str(exprs)
> List of 1
>  $ : language 1 + 2
>
> as well as:
>
>> exprs <- dots(1+2, "a", rnorm(3))
>> str(exprs)
> List of 3
>  $ : language 1 + 2
>  $ : chr "a"
>  $ : language rnorm(3)
>
> Is this possible to achieve using plain R code?

You could use match.call, for example:

  dots <- function(...) match.call(expand.dots = FALSE)[['...']]

Note that this returns a pairlist, so if you want an ordinary list you
should wrap it in as.list()

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[Rd] Package compiler - efficiency problem

2018-08-12 Thread Karol Podemski 
 Dear R team,

I am a co-author and maintainer of one of R packages distributed by R-forge
(gEcon). One of gEcon package users found a strange behaviour of package (R
froze for couple of minutes) and reported it to me. I traced the strange
behaviour to compiler package. I attach short demonstration of the problem
to this mail (demonstration makes use of compiler and tictoc packages only).

In short, the compiler package has problems in compiling large functions -
their compilation and execution may take much longer than direct execution
of an uncompiled function. Such functions are generated by gEcon package as
they describe steady state for economy.

I am curious if you are aware of such problems and plan to handle the
efficiency issues. On one of the boards I saw that there were efficiency
issues in rpart package but they have been resolved. Or would you advise to
turn off JIT on package load (package heavily uses such long functions
generated whenever a new model is created)?

Best regards,
Karol Podemski


possible_bug_report.tar.gz
Description: GNU Zip compressed data
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Re: [Rd] substitute() on arguments in ellipsis ("dot dot dot")?

2018-08-12 Thread Peter Meilstrup 
Interestingly,

   as.list(substitute(...()))

also works.

On Sun, Aug 12, 2018 at 1:16 PM, Duncan Murdoch
 wrote:
> On 12/08/2018 4:00 PM, Henrik Bengtsson wrote:
>>
>> Hi. For any number of *known* arguments, we can do:
>>
>> one <- function(a) list(a = substitute(a))
>> two <- function(a, b) list(a = substitute(a), b = substitute(b))
>>
>> and so on. But how do I achieve the same when I have:
>>
>> dots <- function(...) list(???)
>>
>> I want to implement this such that I can do:
>>
>>> exprs <- dots(1+2)
>>> str(exprs)
>>
>> List of 1
>>   $ : language 1 + 2
>>
>> as well as:
>>
>>> exprs <- dots(1+2, "a", rnorm(3))
>>> str(exprs)
>>
>> List of 3
>>   $ : language 1 + 2
>>   $ : chr "a"
>>   $ : language rnorm(3)
>>
>> Is this possible to achieve using plain R code?
>
>
> I think so.  substitute(list(...)) gives you a single expression containing
> a call to list() with the unevaluated arguments; you can convert that to
> what you want using something like
>
> dots <- function (...) {
>   exprs <- substitute(list(...))
>   as.list(exprs[-1])
> }
>
> Duncan Murdoch
>
>
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> https://stat.ethz.ch/mailman/listinfo/r-devel

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