From h.wickham at gmail.com  Wed Jan 20 15:23:03 2010
From: h.wickham at gmail.com (hadley wickham)
Date: Wed, 20 Jan 2010 08:23:03 -0600
Subject: [Rd] Lightweight 'package' idea.
In-Reply-To: <d8ad40b50908210503xf67354fhfd5f3beede550df0@mail.gmail.com>
References: <d8ad40b50908210503xf67354fhfd5f3beede550df0@mail.gmail.com>
Message-ID: <f8e6ff051001200623x3a909217y5f41e54498b9f3d2@mail.gmail.com>

On Fri, Aug 21, 2009 at 6:03 AM, Barry Rowlingson
<b.rowlingson at lancaster.ac.uk> wrote:
> I'm often wanting to develop functions whilst manipulating data. But I
> don't want to end up with a .RData full of functions and data. It
> might be that I have functions that are re-usable but not worth
> sticking in a package.
>
> ?So I've tried to come up with a paradigm for function development
> that more closely follows the way Matlab and Python do it (partly
> inspired by a confused Matlab convert over on R-help).
>
> ?My requirements were thus:
>
> ?* .R files as the master source for R functions
> ?* Don't see the functions in ls()
> ?* After editing R, make it easy to update the definitions visible to
> R (unlike rebuilding and reloading a package).
>
> ?So I wrote these two in a few mins:
>
> loadDir <- function(dir){
> ?e = attach(NULL,name=dir)
> ?assign("__path__",dir,envir=e)
> ?reloadDir(e)
> ?e
> }
>
> reloadDir <- function(e){
> ?path = get("__path__",e)
> ?files = list.files(path,".R$",full.names=TRUE,recursive=TRUE,ignore.case=TRUE)
> ?for(f in files){
> ? ?sys.source(f,envir=e)
> ?}
> }

Rather than using __path__, why not just use chdir = TRUE in
sys.source() and rely on the usual R working directory semantics?

> ?Sourcing everything on any change seems a bit wasteful, but until R
> objects have timestamps I can't think of a better way. Hmm, maybe my
> environment could keep a __timestamp__ object... Okay, this is getting
> less simple now...

That's what I do for all of my packages during development.  You
really need a huge amount of code before it starts to take a
noticeable amount of time.

Hadley

-- 
http://had.co.nz/



[Rd] Lightweight 'package' idea.
hadley wickham