On Thu, 27 Nov 2003, Paul Brannan wrote:
> Date: Thu, 27 Nov 2003 06:29:10 +0900
> From: Paul Brannan <>
> Newsgroups: comp.lang.ruby
> Subject: Re: Time#succ ?
>
> On Mon, Nov 24, 2003 at 05:36:49AM +0900, Hal Fulton wrote:
> > Should this be added? It would enable the creation
> > of Time ranges like t1..t2 and so on.
>
> Does this not already work?
>
> [pbrannan@zaphod ruby]$ irb
> irb(main):001:0> t = Time.now
> => Wed Nov 26 16:27:46 EST 2003
> irb(main):002:0> (t .. t+1)
> => Wed Nov 26 16:27:46 EST 2003..Wed Nov 26 16:27:47 EST 2003
>
> (the problem only comes if you want to iterate over the range, which
> seems to me to be an ill-defined operation).
anyone familiar with the 'jot' unix program? i think ranges should work like
that - eg. one should be able to define the increment
day = 60 * 60 * 24
a = Time.now
b = Time.now + (7 * day)
week = (a...b)
week.each(step = day) do |weekday|
...
end
as it is needs to overide the #succ method of an object for that to occur.
i realize this is problematic since currently ranges only rely on having a
#succ method, but perhaps this could be extend such that Range#each takes an
optional argument, step. if this is given it will be passed to the objects
#step method, something similar to:
~ > cat timestep.rb
class Range
alias __each each
def each step = nil, &block
nxt, e = self.begin, self.end
if nxt.respond_to? :step
loop do
yield nxt
nxt = nxt.step step
break if (exclude_end? ? nxt >= e : nxt > e)
end
else
__each &block
end
end
end
class Time;
def step n; self + n; end
end
a = Time.now
b = Time.now + (7 * 24 * 60 * 60)
week = (a...b)
week.each(24 * 60 * 60) do |day|
p day
end
~ > ruby timestep.rb
Wed Nov 26 15:29:18 MST 2003
Thu Nov 27 15:29:18 MST 2003
Fri Nov 28 15:29:18 MST 2003
Sat Nov 29 15:29:18 MST 2003
Sun Nov 30 15:29:18 MST 2003
Mon Dec 01 15:29:18 MST 2003
Tue Dec 02 15:29:18 MST 2003
Wed Dec 03 15:29:18 MST 2003
-a
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