[R] terminology for frames and environments
john.maindonald at anu.edu.au
Mon Jun 14 13:30:25 CEST 2004
> From: Peter Dalgaard <p.dalgaard at biostat.ku.dk>
> Date: 14 June 2004 5:42:29 PM
> "Gabor Grothendieck" <ggrothendieck at myway.com> writes:
>> Could someone please clarify what standard terminology is?
> Not sure there is one...
> We have been approaching consensus on a couple of occasions, but
> (obviously) not been too good at enforcing it. I think the consensus
> is that a "frame" is a set of variable bindings (implemented as a
> hashed list), an environment is a frame plus an enclosing environment,
> i.e. a linked list of frames, terminated by NULL. It is occasionally
> necessary to refer to the individual frames as opposed to the whole
> list, which is exactly the point of the inherits argument.
> Notice that exists() talks about "enclosing" which is only ever used
> in sense #1 above. "parent" is used in both senses (which is a bit
> unfortunate -- not quite sure whether we have decided to get rid of
> parent.env() eventually).
> O__ ---- Peter Dalgaard Blegdamsvej 3
> c/ /'_ --- Dept. of Biostatistics 2200 Cph. N
> (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918
> ~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk) FAX: (+45) 35327907
I have found it helpful, in trying to explain (to myself and others)
what happens, to say that there is both a lexical stack and a call
stack. Is that a legitimate use of terminology?
John Maindonald email: john.maindonald at anu.edu.au
phone : +61 2 (6125)3473 fax : +61 2(6125)5549
Centre for Bioinformation Science, Room 1194,
John Dedman Mathematical Sciences Building (Building 27)
Australian National University, Canberra ACT 0200.
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