[R] If statement generates two outputs

[Wacek Kusnierczyk]

Berwin A Turlach wrote:
> G'day Carl,
>
> On Mon, 23 Mar 2009 20:11:19 -0400
> Carl Witthoft <carl at witthoft.com> wrote:
>
>   
>>  >From: Wacek Kusnierczyk <Waclaw.Marcin.Kusnierczyk_at_idi.ntnu.no>
>>  >Date: Sun, 22 Mar 2009 22:58:49 +0100
>>
>>
>>  >just for fun, you could do this with multiassignment, e.g., using
>>  >the (highly experimental and premature!) rvalues:
>>
>>  >    source('http://miscell.googlecode.com/svn/rvalues/rvalues.r') 
>>  >if (TRUE)
>>
>>  >       c(df1, df2) := list(4:8, 9:13)
>>
>>  >    dput(df1)
>>  >    # 4:8
>>  >    dput(df2)
>>  >    # 9:13
>>
>>
>> -------
>> Now THAT's what I call an overloaded operator!   ^_^
>>     

it's not really overloaded, it's *loaded*.  if you type

    a :=  1

in an r session without defining '=', r cannot 'find such a function',
but it doesn't complain about invalid syntax.  so there is the operator,
only that it's not operational. 

>> But seriously:  can someone explain to me what's going on in the 
>> rvalues.r code? 

i think i-the-sinner'd be the right person to ask.  i'd suggest to
discuss offline, because rvalues is really an experiment, a proof of
concept, and as such may not be of interest for wider audience.  (it
might be that it will be developed into something substantial, but no
guarantees.)

vQ