[R] Google style

Jim Lemon jim at bitwrit.com.au
Tue Sep 1 11:47:25 CEST 2009


Duncan Murdoch wrote:
> On 8/31/2009 11:50 AM, Mark Knecht wrote:
>> On Mon, Aug 31, 2009 at 6:36 AM, Terry Therneau<therneau at mayo.edu> 
>> wrote:
>> <SNIP>
>>> The authors borrowed so much else from C, the semicolon would have been
>>> good too.
Something I have thought myself.
>>  
>>
>> I know real R coders will chuckle
>
> I'd say cringe, rather than chuckle.  This is going to make you waste 
> a lot of time some day, when you stare and stare at code like Terry's 
> and can't figure out what's wrong with it:
>
>     zed <- function(x,y,z) {
>            x + y
>                  +z;
>           }
>
> The value of the function is +z, not x+y+z, even though the C part of 
> your brain made you type it that way and reads it as one statement in 
> the body, not two.
This is getting interesting. One habit I have developed in R to 
emphasize a line continuation is to always write the above as:

zed<-function(x,y,z) {
 x+y+
 z
}

The trailing operator signalling to me and the interpreter that there's 
more to come. A semicolon after the z would be innocuous. Now I know 
that this marks me as a crabby old fart who learned to program on 
Hollerith cards where there had to be firm conventions on when a line of 
code ended. Still, given the moiety of global warming attributable to 
endless discussions about how many spaces should be used for 
indentation, I think the use of the semicolon as a personal aid to 
interpretation is at worst a harmless affectation.

Jim




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