unlist change the ordered type

Hi the list,

unlist respect the all the atomic type except orderd (it change of ordered 
into factor) :

### integer
class(unlist(list(1:5,1:3)))
#[1] "integer"

### numeric
class(unlist(list(1.2,3.5)))
#[1] "numeric"

### character
class(unlist(list("e","e")))
#[1] "character"

### factor
class(unlist(list(factor("e"),factor("e"))))
#[1] "factor"

### ordered
class(unlist(list(ordered("e"),ordered("e"))))
#[1] "factor"

Christophe

On Fri, 24 Oct 2008, Christophe Genolini wrote:

Hi the list,

unlist respect the all the atomic type except orderd (it change of 
ordered into factor) :

### integer
class(unlist(list(1:5,1:3)))
#[1] "integer"

### numeric
class(unlist(list(1.2,3.5)))
#[1] "numeric"

### character
class(unlist(list("e","e")))
#[1] "character"

### factor
class(unlist(list(factor("e"),factor("e"))))
#[1] "factor"

### ordered
class(unlist(list(ordered("e"),ordered("e"))))
#[1] "factor"

Consider

	unlist(list(ordered(1:2),ordered(letters[1:4])))

Since one cannot deduce what ordering should apply, the best that can 
be done is to demote all arguments to factors.

This is the general case. Only in the special case in which all list 
elements are of class 'ordered' and the levels attributes are the 
same would this be sensible.