[R] A technical question on methods for "+"

[Jeff Newmiller]

I think the fact that character is a built-in type rather than an S3 class has something to do with it.

On December 2, 2021 11:31:47 AM PST, Bert Gunter <bgunter.4567 using gmail.com> wrote:
>... and probably a dumb one and almost certainly not of interest to
>most R users. But anyway...
>
>?"+" says:
>"The unary and binary arithmetic operators are generic functions:
>methods can be written for them individually or via the Ops group
>generic function. "
>
>So:
>"+.character" <- function(e1, e2) paste0(e1, e2)
>## but this doesn't 'work':
>> "a" + "b"
>Error in "a" + "b" : non-numeric argument to binary operator
>
>## but explicitly invoking the method does 'work' :
>> "+.character"('a','b')
>[1] "ab"
>
>##Note also:
>> methods("+")
>[1] +.character +.Date      +.IDate*    +.POSIXt    +.trellis*
>
>So what am I failing to understand?
>Thanks.
>
>Bert Gunter
>
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-- 
Sent from my phone. Please excuse my brevity.