Message-ID: <E176A8C3-6428-4AAA-9840-ACA09C314D26@uni-goettingen.de>
Date: 2011-12-16T12:36:24Z
From: Daniel Adler
Subject: makeNamespace and rdyncall
Dear R Core Team,
I have a question related to the programming interface for namespace object creation at run-time.
This is something that I need in the rdyncall package:
During the dynamic linkage binding of a shared C library, an R namespace object is created
that gets populated with call wrappers, symbolic constants and type information objects.
For example,
> dynport(SDL) # create namespace, populated with wrappers to SDL library
> search() # gives a "package:SDL" populated with all kinds of wrappers to the C functions, etc..
[1] ".GlobalEnv" "package:SDL"
I was trying various alternatives to get package-behaviour implemented in transparent manner for the end-user.
The current version uses real namespace environments with all sorts of advantages such as support for
search(), detach() and '::'.
Namespace object have certain conventions for fields, and there is currently no
public interface available in 'base' for setting up such objects;
The function "makeNamespace" in src/library/base/namespace.R is defined as local function to "loadNamespace".
So I go about this problem by 'copying' the code.
Recently, R-2.14 introduced a new mandatory field 'lazyData' which mades rdyncall broken.
(By re-synchronizing with 'makeNamespace' it has been fixed in 0.7.4.)
Would it be possible and feasible to make namespace-related management functions such as makeNamespace and sealNamespace
available as an public accessible interface? Or at least accessible via ':::' ?
I would also appreciate any hint/idea for alternative ways to implement the above described behaviour.
Here is the link to the code used for creation of dynamic C binding namespaces: http://dyncall.org/svn/dyncall/trunk/bindings/R/rdyncall/R/dynport.R
best wishes,
- Daniel