Generates ranges of integers.
# range {end}
# range {start} {end}
# range {start} {end} {step}
range 0 #--> []
range 4 #--> [ 0, 1, 2, 3 ]
range 4 7 #--> [ 4, 5, 6 ]
range 4 14 2 #--> [ 4, 6, 8, 10, 12 ]
range (-4) #--> [ 0, -1, -2, -3 ]
range 9 1 (-2) #--> [ 9, 7, 5, 3 ] ]
range from: 9 to: 1 by: -2
# or
range start: 9 end: 1 step: -2
#
# are also accepted