Template functions to generate basic S3 methods for new classes

create_s3_method creates a method that applies NextMethod but that also keeps additional attributes (such as class). create_s3_print creates a print method.

create_s3_method(generic = NULL, object = NULL)

create_s3_print(fun, ...)

Arguments

generic, object	as described for NextMethod
fun	Function to transform object before print (probably as.character, as.numeric or similar).
...	additional arguments passed to print method

Value

S3-method.

Details

Don't forget to also create for example a data.frame method by

as.data.frame.xxx <- as.data.frame.vector

Examples

a <- structure(1:10, class = c("b", "numeric"))
a[3] # Normal subsetting makes a loose its attributes
#> [1] 3
`[.b` <- create_s3_method("[")
print.b <- create_s3_print(as.numeric)
a[3] # attributes preserved even if we can't see them
#> [1] 3
#> attr(,"class")
#> [1] "b"       "numeric"
str(a[3])
#>  'b' int 3