From peter.meilstrup at gmail.com  Fri Oct  5 03:31:26 2012
From: peter.meilstrup at gmail.com (Peter Meilstrup)
Date: Thu, 4 Oct 2012 18:31:26 -0700
Subject: [Rd] How to build a list with missing values? What is missing,
	anyway?
In-Reply-To: <CACk-te23paBonBtKY+eNoqVVdz_0186Y-DnfaMQ4zJOsZS-Gww@mail.gmail.com>
References: <CAJoaRhb8gq79aB3EXPeMa+n6eK6pj9NTFHFBJRUbP_=S1bbTaA@mail.gmail.com>
	<1349331704206-4644965.post@n4.nabble.com>
	<CAJoaRhbgikc=3Gpa8LAvSakjE=e95Z5akS7w5dHEND+yWHfJ6Q@mail.gmail.com>
	<CACk-te23paBonBtKY+eNoqVVdz_0186Y-DnfaMQ4zJOsZS-Gww@mail.gmail.com>
Message-ID: <CAJoaRhYaRyoSzCKWgNNsuo63BazcG_CPDaAW_o4bXMMTeUdeLA@mail.gmail.com>

On Thu, Oct 4, 2012 at 6:12 PM, Bert Gunter <gunter.berton at gene.com> wrote:
> The R Language definition manual explains all of this. Read it.

I always reread that before I post to this list.

The only relevant mention of "missing" in the R Language Definition
that I could find were in section 4.1.2 on page 25, and that section
did not answer anything about "missing" as a special symbol (e.g. that
my be put in a formal argument list.)

There is another mention of `...` in section 4.3.2 and it does not
explain some things, such as under what circumstances one would get a
"`...` used in incorrect context" error.

Peter

>>
>> Thanks.
>>
>> Just so I have my mental model correct, I'm gathering that missing/``
>> is a symbol that the interpreter has a special rule for -- evaluating
>> it raises an error, as opposed to objects that evaluate to themselves
>> or variable names that evaluate to objects.
>>
>> Does the same sort of thing explain the behavior of `...`? When the
>> interpreter comes across `...` in the arguments during evaluation of a
>> call, it trips a special argument-interpolating behavior?
>>
>> Peter
>>
>> ______________________________________________
>> R-devel at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>
>
>
> --
>
> Bert Gunter
> Genentech Nonclinical Biostatistics
>
> Internal Contact Info:
> Phone: 467-7374
> Website:
> http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm



[Rd] How to build a list with missing values? What is missing, anyway?
Peter Meilstrup