[R] Is = now the same as <- in assigning values

[Wacek Kusnierczyk]

Wacek Kusnierczyk wrote:
> Kenn Konstabel wrote:
>   
>> Hi,
>>
>> On Tue, Dec 16, 2008 at 9:13 AM, Wacek Kusnierczyk <
>> Waclaw.Marcin.Kusnierczyk at idi.ntnu.no> wrote:
>>
>>   
>>     
>>> ... but this is also legal if you really hate <- :
>>>
>>> foo({x = 2})
>>> # assign to x, pass to foo as a
>>>
>>>     
>>>       
>> This is legal but doesn't do what you probably expect -- although
>> documentation for `<-` says the value (returned by <-) is 'value' i.e.
>> whatever is on the right side ...
>>   
>>     
>
> as far as i can see, this does precisely what i expect -- it assigns 2
> to x and then passes x as the argument a to foo.  did you mean there is
> something else happening here?
>   

too quick this time:  the 'then' is not appropriate, as it is an
expression, not its value, that is passed to foo.  so this does what i
expect, and what i'd expect with x <- 2 instead, namely:  x is assigned
2 on the first occasion the argument a is used within foo, and
effectively a has the value of x after the assignment.


vQ