R devel - Mar 2011 - Create an environment and assign objects to it in one go?

Hi,

I've just created:

newEnvEval <- function(..., hash=FALSE, parent=parent.frame(), size=29L) {
  envir <- new.env(hash=hash, parent=parent, size=size);
  evalq(..., envir=envir);
  envir;
} # newEnvEval()

so that I can create an environment and assign objects to it in one go, e.g.

env <- newEnvEval({ a <- 1; b <- 2; });
print(env$a);

Does this already exists somewhere?

/Henrik

PS.

On Mar 10, 2011, at 08:44 , Henrik Bengtsson wrote:
> Hi,
> 
> I've just created:
> 
> newEnvEval <- function(..., hash=FALSE, parent=parent.frame(), size=29L)
{
>  envir <- new.env(hash=hash, parent=parent, size=size);
>  evalq(..., envir=envir);
>  envir;
> } # newEnvEval()
> 
> so that I can create an environment and assign objects to it in one go,
e.g.
> 
> env <- newEnvEval({ a <- 1; b <- 2; });
> print(env$a);
> 
> Does this already exists somewhere?
> 
I think 

env <- local({ a <- 1; b <- 2; environment()})
env$a 

-pd
> /Henrik
> 
> PS.
> 
> ______________________________________________
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-- 
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

On 3/10/11, Henrik Bengtsson <hb at biostat.ucsf.edu>
wrote:
> Hi,
>
> I've just created:
>
> newEnvEval <- function(..., hash=FALSE, parent=parent.frame(), size=29L)
{
>   envir <- new.env(hash=hash, parent=parent, size=size);
>   evalq(..., envir=envir);
>   envir;
> } # newEnvEval()
>
> so that I can create an environment and assign objects to it in one go,
e.g.
>
> env <- newEnvEval({ a <- 1; b <- 2; });
> print(env$a);
>
> Does this already exists somewhere?
>
> /Henrik
>
You can do this:

   e <- as.environment(list(a = 1, b = 2))
   e$a; e$b

or since proto objects are environments (but the $ has slightly
different semantics when applied to functions):

   library(proto)
   p <- proto(a = 1, b = 2, expr = { c <- 3 })
   p$a; p$b; p$c




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