It is going to be too hard to move to vec_arith() and ensure that we are 100% backwards compatible with the original + and - implementations. Instead, we provide a double dispatch entry point where packages like clock and almanac can inject special behavior with their types when + and - don't work properly
library(slider)
library(clock)
i <- as.Date("2019-01-01") + 0:5
x <- seq_along(i)
# Doesn't work. But clock has `vec_arith()` methods for this!
slide_index(x, i, identity, .before = duration_days(2))
#> Warning in fn_default(x, y): Incompatible methods ("-.Date", "-.vctrs_vctr") for
#> "-"
#> Error in x - y: non-numeric argument to binary operator
# So clock can register this double dispatch method:
slider_minus.Date.clock_duration <- function(x, y) {
vctrs::vec_arith("-", x, y)
}
slide_index(x, i, identity, .before = duration_days(2))
#> [[1]]
#> [1] 1
#>
#> [[2]]
#> [1] 1 2
#>
#> [[3]]
#> [1] 1 2 3
#>
#> [[4]]
#> [1] 2 3 4
#>
#> [[5]]
#> [1] 3 4 5
#>
#> [[6]]
#> [1] 4 5 6
Closes #91
It is going to be too hard to move to
vec_arith()and ensure that we are 100% backwards compatible with the original+and-implementations. Instead, we provide a double dispatch entry point where packages like clock and almanac can inject special behavior with their types when+and-don't work properlyCreated on 2022-11-09 with reprex v2.0.2.9000