Python-like range operator in R, allowing to specify step size

xrange.r

`:` = function (a, b) {
    if (inherits(a, 'xrange'))
        do.call(seq, as.list(c(range(a), by = b)))
    else if (inherits(a, 'factor'))
        interaction(a, b, sep = ':')
    else
        structure(seq(a, b), class = 'xrange')
}

print.xrange = function (x)
    print(as.numeric(x))

# > 1 : 5
#  [1] 1 2 3 4 5
# > 1 : 10 : 2
#  [1] 1 3 5 7 9
# > 1 : 5 : 2 * 2
#  [1]  2  6 10