Map a function over a lens

Get the data pointed to by a lens, apply a function and replace it with the result.

over(d, l, f)

Arguments

d	the data (or an oscope)
l	the lens (or the function if d is an oscope)
f	the function (or nothing if d is an oscope)

Examples

third_l <- index(3)
over(1:5, third_l, function(x) x + 2)
#> [1] 1 2 5 4 5
# returns c(1:2, 5, 4:5)