r - How can I create an infix %between% operator?

Question

I would like to have an infix operator %between% in R -- to check to see if x is between lower bound l and upper bound u.

I have created the following simple function -- but it's not an infix operation.

# between function - check to see if x is between l and u
is.between <- function(x, l, u) { x > l & x < u }

My aim is to replace this with: x %between% c(l, u)

Is it possible to define new infix operations? If so, how does one do this?

thanks in advance

Answer 1

You can define infix operators as functions:

`%between%`<-function(x,rng) x>rng[1] & x<rng[2]
1 %between% c(0,3)
# [1] TRUE
1 %between% c(2,3)
# [1] FALSE

As pointed out by @flodel, this operator is vectorized:

1:5 %between% c(1.5,3.5)
# [1] FALSE  TRUE  TRUE FALSE FALSE