[Rd] Documentation for is.atomic and is.recursive

hadley wickham h.wickham at gmail.com
Wed Sep 2 21:02:06 CEST 2009


On Wed, Sep 2, 2009 at 1:54 PM, Stavros Macrakis<macrakis at alum.mit.edu> wrote:
> On Wed, Sep 2, 2009 at 2:39 PM, Stavros Macrakis<macrakis at alum.mit.edu> wrote:
>
>>      Most types of language objects are regarded as recursive: those
>>      which are not are the atomic vector types, 'NULL' and symbols (as
>>      given by 'as.name').
>>
>> But is.recursive(as.name('foo')) == is.recursive(quote(foo)) == FALSE.
>
> Sorry, this *is* consistent with the behavior.  But if we read "the
> atomic vector types, 'NULL' and symbols" as a list of mutually
> exclusive categories, then is.atomic(NULL)==FALSE is inconsistent.

And the sentence could be more clearly written as:

Most types of language objects are regarded as recursive, except for
atomic vector types, 'NULL' and symbols (as given by 'as.name').

Hadley


-- 
http://had.co.nz/



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