From kynnjo at gmail.com  Mon Oct  3 02:01:58 2016
From: kynnjo at gmail.com (Kynn Jones)
Date: Sun, 2 Oct 2016 20:01:58 -0400
Subject: [Rd] On implementing zero-overhead code reuse
In-Reply-To: <20161002230956.GT9995@ofb.net>
References: <CAFvQaj4Bcd-FW_z2Sc019d9JUa_Xy3Xz0HO=Ze16ZLnGJx4JiQ@mail.gmail.com>
	<20161002230956.GT9995@ofb.net>
Message-ID: <CAFvQaj4SLxim=Jqi_yeOrKTRvuhWB7X-C6xXjpCw_pbmfz_=3Q@mail.gmail.com>

Hi Frederick,

I described what I meant in the post I sent to R-help
(https://stat.ethz.ch/pipermail/r-help/2016-September/442174.html),
but in brief, by "zero overhead" I mean that the only thing needed for
library code to be accessible to client code is for it to be located
in designed directory.  No additional meta-files, packaging/compiling,
etc. are required.

Best,

G.

On Sun, Oct 2, 2016 at 7:09 PM,  <frederik at ofb.net> wrote:
> Hi Kynn,
>
> Do you mind defining the term "zero-overhead model of code reuse"?
>
> I think I understand what you're getting at, but not sure.
>
> Thank you,
>
> Frederick
>
> On Sun, Oct 02, 2016 at 01:29:52PM -0400, Kynn Jones wrote:
>> I'm looking for a way to approximate the "zero-overhead" model of code
>> reuse available in languages like Python, Perl, etc.
>>
>> I've described this idea in more detail, and the motivation for this
>> question in an earlier post to R-help
>> (https://stat.ethz.ch/pipermail/r-help/2016-September/442174.html).
>>
>> (One of the responses I got advised that I post my question here instead.)
>>
>> The best I have so far is to configure my PROJ_R_LIB environment
>> variable to point to the directory with my shared code, and put a
>> function like the following in my .Rprofile file:
>>
>>     import <- function(name){
>>         ## usage:
>>         ## import("foo")
>>         ## foo$bar()
>>         path <- file.path(Sys.getenv("PROJ_R_LIB"),paste0(name,".R"))
>>         if(!file.exists(path)) stop('file "',path,'" does not exist')
>>         mod <- new.env()
>>         source(path,local=mod)
>>         list2env(setNames(list(mod),list(name)),envir=parent.frame())
>>         invisible()
>>     }
>>
>> (NB: the idea above is an elaboration of the one I showed in my first post.)
>>
>> But this is very much of an R noob's solution.  I figure there may
>> already be more solid ways to achieve "zero-overhead" code reuse.
>>
>> I would appreciate any suggestions/critiques/pointers/comments.
>>
>> TIA!
>>
>> kj
>>
>> ______________________________________________
>> R-devel at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>



[Rd] On implementing zero-overhead code reuse
Kynn Jones