[Rd] assign, documentation (PR#1434)

p.dalgaard@biostat.ku.dk p.dalgaard@biostat.ku.dk
Thu, 4 Apr 2002 18:18:10 +0200 (MET DST)

Robert Gentleman <rgentlem@jimmy.harvard.edu> writes:

> > > >  In all the assignment operator expressions, `x' can be a name or
> > > >  an expression defining a part of an object to be replaced (e.g.,
> > > >  `z[[1]]').  The name does not need to be quoted, though it can be.
> > One improvement might be: "the name can be any string of text and may
> > be quoted, but this is only necessary if it is not a syntactically
> > valid name."
> > 
>   I think the original point was that he expected that a[1] would be
>   changed not that a new variable named "a[1]" would be created. I
>   don't think your suggestion will help with this. I think that Brian
>   is correct, unless of course you want to spend some amount of time
>   figuring out the logic/parsing requirements.
>   "Assign treats the quoted string as a symbol, it does not parse it in
>   any way", might help.  On the otherhand, in some large number of
>   years this is the first person who has had this problem, I'm not
>   sure we should be documenting for less than 1% of the population 
>   unless of course,
>     "we are trying to be as accurate as possible without regard to
>   readability"  :-), to quote the views of a certain member of R core
>   on documentation.

Moi? Only for certain kinds of documentation as you surely know. In
other contexts I'd willingly go for reducing precision to improve
overall clarity. But I do think accuracy is more important than
anything else on help pages. It is the wrong context in which to try
to be pedagogical.

This really is the place to pick nits, and, e.g., the argument to
assign is *not* a quoted string; it is a character vector whose first
element becomes the name of the assigned object.

The nit I was picking was in fact not relevant for the original
question, but would be in the "a[1]" <- 2 case. The improvement is
that there are cases where you *must* quote the left hand side, in
contrast with what the help page is saying.

   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk)             FAX: (+45) 35327907

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