[Rd] syntax difference clusterExport in parallel and snow

[Hervé Pagès]

On 12/13/2016 09:33 AM, Prof Brian Ripley wrote:
> On 13/12/2016 17:05, Paul Johnson wrote:
>> We got some errors and eventually figured out that
>> parallel::clusterExport second argument is "varlist" while in
>> snow::clusterExport it is "list".
>>
>> The user had loaded parallel first, but did something else which
>> inadvertently loaded snow, then clusterExport failed because we had
>> "varlist" and not "list".
>>
>> Are these different on purpose?
>
> Yes.
>
> ('list' is an unhelpful name for an argument that is not a list.)
>
>

Yes 'list' is a misleading name for a character vector. OTOH I guess
snow::clusterExport() was just following the lead of base::save() and
base::remove() on this.

I don't see 'varlist' as being much less confusing though: it still
suggests that the thing is a list and parallel::clusterExport() is
now inconsistent with snow::clusterExport(). So it doesn't really
address the 1st problem and introduces a new one. Sounds like using
a plural form instead of the "list" prefix would be less confusing
e.g. 'vars', 'varnames', 'objnames' or something like that.

H.

-- 
Hervé Pagès

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