[R] Multiple line commands in R scripting

[Duncan Murdoch]

On 25/10/2009 11:43 AM, Peter Ehlers wrote:
> Here are two ways:
> 
> 1. wrap the line in braces:
> 
>   x <- {....
>         /...}

That doesn't work.  You're probably thinking of the way the parsing of 
if versus if/else depends on braces:

  if (TRUE) print("TRUE")
  else print("FALSE")

is a syntax error, except when wrapped in braces.

Duncan Murdoch

> 
> 2. maybe more awkward in general, but sometimes useful:
> 
>   x <- `/`(... ,
>         ...)
> 
>   -Peter Ehlers
> 
> Neil Stewart wrote:
>> I'm wondering whether there is a character to let R know to expect more
>> input for a command on subsequent lines. Here is an example:
>>
>> test_1.R:
>> x <- c(1,2,3,4)
>>     / c(1,2,3,4)
>> x
>>
>> R CMD BATCh test_1.R produces test_1.Rout:
>>> x <- c(1,2,3,4)
>>>   / c(1,2,3,4)
>> Error: unexpected '/' in "  /"
>> Execution halted
>>
>>
>> test_2.R:
>> x <- c(1,2,3,4) /
>>     c(1,2,3,4)
>> x
>>
>> R CMD BATCh test_1.R produces test_2.Rout:
>>> x <- c(1,2,3,4) /
>> +   c(1,2,3,4)
>>> x
>> [1] 1 1 1 1
>>
>> test_2.R works as expected but test_1.R fails because the "/" operator is at
>> the start of line 2 not the end of line 1.
>>
>> Is the some kind of continuation charater one can include in a script so R
>> is expecting input on the next line? For example, in other languages, "\"
>> works. Without this, one is forced to break lines carefully in the middle of
>> a function, for example, to ensure R is expecting more. Any comments very
>> welcome.
>>
>> Thank you,
>> Neil.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.