Re: [Rd] Trying to understand the search path and namespaces

2010-11-16 Thread Berwin A Turlach
G'day Hadley, On Tue, 16 Nov 2010 07:35:09 -0600 Hadley Wickham wrote: > > Well, as the part of "Writing R Extensions" that Martin quoted > > states, the normal search path is part of the search path used by > > packages with name spaces.  So if you attach another package via > > library(), the

Re: [Rd] Trying to understand the search path and namespaces

2010-11-16 Thread Hadley Wickham
>> Ah, my mistake was assuming that the package namespace and environment >> were the same thing. >> >> Interestingly the namespace is dynamic: > > Not sure what you mean with this.  Section 1.6 of "Writing R > Extensions" explicitly states: > >        Name spaces are @emph{sealed} once they are lo

Re: [Rd] Trying to understand the search path and namespaces

2010-11-16 Thread Berwin A Turlach
G'day Hadley, On Mon, 15 Nov 2010 19:45:30 -0600 Hadley Wickham wrote: > > 1.6 of Writing R Extensions says > > > > Note that adding a name space to a package changes the search > > strategy. The package name space comes first in the search, then > > the imports, then the base name space and the

Re: [Rd] Trying to understand the search path and namespaces

2010-11-15 Thread Mark Leeds
Hi Duncan: Luke's article is in the June, 2003 edition of R-news On Mon, Nov 15, 2010 at 8:43 PM, Duncan Murdoch wrote: > Hadley Wickham wrote: > >> Hi all, >> >> I'm trying to understand how the search path and namespaces interact. >> For example, take the devtools package which suggests the te

Re: [Rd] Trying to understand the search path and namespaces

2010-11-15 Thread Hadley Wickham
> 1.6 of Writing R Extensions says > > Note that adding a name space to a package changes the search strategy. > The package name space comes first in the search, then the imports, then > the base name space and then the normal search path. > > I'm not sure of the details, but I think > >  parents(

Re: [Rd] Trying to understand the search path and namespaces

2010-11-15 Thread Duncan Murdoch
Hadley Wickham wrote: Hi all, I'm trying to understand how the search path and namespaces interact. For example, take the devtools package which suggests the testthat package. Here's what the search path looks like after I load each of those packages: Luke Tierney wrote up a nice description

Re: [Rd] Trying to understand the search path and namespaces

2010-11-15 Thread Martin Morgan
On 11/15/2010 04:56 PM, Hadley Wickham wrote: >> Well, that's what I thought too. But: >> >> parents <- function(x) { >> if (identical(x, emptyenv())) return() >> c(environmentName(x), parents(parent.env(x))) >> } >>> parents(as.environment("package:devtools")) >> [1] "package:devtools" "package

Re: [Rd] Trying to understand the search path and namespaces

2010-11-15 Thread Hadley Wickham
> Well, that's what I thought too.  But: > > parents <- function(x) { >  if (identical(x, emptyenv())) return() >  c(environmentName(x), parents(parent.env(x))) > } >> parents(as.environment("package:devtools")) > [1] "package:devtools" "package:methods"  "Autoloads"        "base" > > And package:t

Re: [Rd] Trying to understand the search path and namespaces

2010-11-15 Thread Hadley Wickham
> With a small risk of being incorrect (and the chance of learning > something new), I'll give it a try: > > A search for a functions/objects/... that is not in the same package > environment is done in the order that the search() path gives.  The > exception to this iff your package has a namespac

Re: [Rd] Trying to understand the search path and namespaces

2010-11-15 Thread Henrik Bengtsson
On Mon, Nov 15, 2010 at 3:26 PM, Hadley Wickham wrote: > Hi all, > > I'm trying to understand how the search path and namespaces interact. > For example, take the devtools package which suggests the testthat > package.  Here's what the search path looks like after I load each of > those packages: