Peña, Botp
10/25/2007 8:23:00 AM
From: Just Another Victim of the Ambient Morality
# start.step(end, step_size)
# ...wasn't more like:
# step_size.step(start, end)
# ...I just like having the start and end points grouped
# together with the
# step size singled out.
# Who's with me?
i'm w you. ruby is with you (quite).
irb(main):016:0> system "qri range.step"
------------------------------------------------------------- Range#step
rng.step(n=1) {| obj | block } => rng
------------------------------------------------------------------------
Iterates over rng, passing each nth element to the block. If the
range contains numbers or strings, natural ordering is used.
Otherwise step invokes succ to iterate through range elements.
irb(main):018:0* (0..10).step(2) {|x| p x}
0
2
4
6
8
10
=> 0..10
obviously, by definition of range, it will not cater negative steps
irb(main):030:0> (10..0).step(-2) {|x| p x}
ArgumentError: step can't be negative
:(
maybe, before i request a change in step, i might as well request a change in #succ/#next first, like succ receiving an optional argument, eg..
1.succ #=> 2
(-1).succ #=> 0
1.succ(1) #=> 2
(-1).succ(1 #=> 0
1.succ(2) #=> 3
(-1).succ(2) #=> 1
1.succ(-1) #=> 0
(-1).succ(-1)#=> -2
so then,
irb(main):030:0> (10..0).step(-2) {|x| p x}
10
8
6
4
2
0
I believe facets already does the succ(-n) part, but does not handle step(-n) which is pretty lame to me, imnho.
kind regards -botp