[R] The use of period in function names and variable names

Uwe Ligges ligges at statistik.tu-dortmund.de
Tue Oct 4 18:24:31 CEST 2011



On 04.10.2011 18:18, Duncan Murdoch wrote:
> On 04/10/2011 7:04 AM, S Ellison wrote:
>> See para 10.3.2 'Identifiers' in the R language definition (always
>> distributed with R in the html help system), or ?make.names, for a
>> concise statement of what constitutes a valid variable name in R.
>>
>> It's actually underscores that might give trouble with older versions,
>> not '.'. But they'd have to be a lot older by R standards (pre 1.9.0).
>>
>> I am not sure why there has been a recent shift away from periods and
>> towards camelCase in some R packages;
>
> Presumably the authors of those packages prefer camelCase. I don't think
> it's any more complicated than that.

I switched to that when I realized that it is somewhat dangerous to 
conflict with S3 naming conventions and R CMD check yelled correctly 
because I used a generic.class notation where either "generic" or 
"class" was really the name of a generic or class but I had not realized 
before.

Uwe



>
> Duncan Murdoch
>
>
>> personally I find a period or underscore much more useful for making a
>> variable name readable. And a mix of camelCase and period.breaks makes
>> it a lot harder to guess which case-sensitive string to use. The
>> number of different combinations of case and period I end up trying
>> for R.Version (occasionally used, never quite often enought to be
>> automatic) defies belief ;-).
>>
>>
>> S Ellison
>>
>> > From: r-help-bounces at r-project.org On Behalf Of Smart Guy
>> > Sent: 04 October 2011 05:20
>> > To: r-help at r-project.org
>> > Subject: [R] The use of period in function names and variable names
>> >
>> > Hi,
>> > I am looking for some guidance on whether I can use the
>> > period(.) in function names and variable names.
>>
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>
> ______________________________________________
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