[Rd] [R] Semantics of sequences in R

Stefan Evert stefan.evert at uos.de
Mon Feb 23 12:12:39 CET 2009

Dear vQ,

> vectors (can-be-considered-lists),

can you please stop repeating this nonsense?  I don't think anybody  
ever claimed that vectors can be considered list.  It's rather the  
other way round: lists can also be seen as vectors to R (possibly they  
are implemented as such, but I don't much about the internals of R).

 > a <- as.list(1:10)
 > b <- 1:10
 > is.vector(a)
[1] TRUE
 > is.list(a)
[1] TRUE
 > is.vector(b)
[1] TRUE
 > is.list(b)

Hence the confusion about

 > mode(as.vector(a))
[1] "list"

which prompted the original comment that you are taking so much  
exception to.

> as to "it could only work in very specific circumstances" -- no, it
> would work for any list whatsoever, provided the user has a correctly
> implemented comparator.  for example, i'd like to sort a list of  
> vectors
> by the vectors' length -- is this a very exotic idea?

Honestly, I can't think of a situation where I would want to do than  
in R.  In a Perl script, quite likely; but this is a kind of data  
manipulation that R wasn't really designed for IMHO.

Not that I'd mind having sort() operate properly on lists; it just  
isn't something I miss in the language.


[ stefan.evert at uos.de | http://purl.org/stefan.evert ]

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