Automatically retrieve correct collation

-----Urspr?ngliche Nachricht-----
Von: baptiste auguie [mailto:baptiste.auguie at googlemail.com]
Gesendet: Donnerstag, 19. August 2010 07:41
An: Janko Thyson
Cc: r-devel at r-project. org
Betreff: Re: [Rd] Automatically retrieve correct collation

Hi,

roxygen can create the collate field for you, if you specify the
dependencies in the commented code. I've never tested it with S4
classes though.

HTH,

baptiste

On 18 August 2010 22:28, Janko Thyson <janko.thyson at ku-eichstaett.de>
wrote:

Dear List,

consider the following scenario:

setClass(Class = "A", representation = representation(B = "B", C =

"C"))

setClass(Class = "B", representation = representation(C = "C"))
setClass(Class = "C", representation = representation(something =
"character"))

Obviously, the collation for sourcing these defs needs to be: C, B,

A. Which

doesn't correspond to the default collation of R (alphabetically).

I've tried to pick up on how to ensure the right collation when

building R

Packages by reading some previous posts and as far as I understand

I've

basically got two options here:
1) Put all class defs in one script, e.g. allClasses.R.
2) Manually specify the collation via the "Collate" field in the

DESCRIPTION

file.

I'm used to organizing my classes, generics, methods etc. on a
"one-per-script" basis in various subdirectories (e.g. R/classes,

R/methods

etc.) and try automate manual steps wherever possible (not sure if

that's

the way most of you guys code, but it definitely helped me stay on

top of

things). But this doesn't really go well with my two options above,

does it?

;-)

So I thought about setting up a routine that
- investigates the source code of all classes (via parsing and

looking into

the "representation" argument)
- finds out the valid collation by itself based on all classes that

it found

in the representation argument of the respective class defs
- and then writes all the class defs to one R script, e.g.

?allClasses.R, so

I can bundle all my code in an R Package without worrying about the
collation.

This way I could stick to my old habits while automating the process

of

building a package a bit ;-)

Now, I managed to get this done for "simple" class defs like the ones

above

but haven't looked into more complex class defs (e.g. including

"contains"

etc.) yet.

Has anyone tried and succeeded in doing something similar or are all

of you

into the "one-script-contains-all" paradigm? If anyone is interested,

I'd be

glad to share code. Likewise I'd be interested in hearing about other

"best

practices" in this respect.

Best regards,
Janko

--