Here’s my solution. It converts a time window into an array of arrays of
ranges. Each range matches an interval of time (e.g.: 500…1700); each
subarray contains all the ranges for a given day. I then wrote the
simple Array#some method that returns true if the given predicate
returns true for at least one of its elements, which I used to write
TimeWindow#incude?.
$days = {“Sun”=>0,
“Mon”=>1,
“Tue”=>2,
“Wed”=>3,
“Thu”=>4,
“Fri”=>5,
“Sat”=>6}
class Array
def some
each {|el| return true if yield el}
false
end
end
class TimeWindow
def initialize(win_str)
@times = ([nil]7).map{[]}
win_str << " " #In case of empty
win_str.split(/;/).each do |win|
days_str = win.match(/(((#{$days.keys.join(‘|’)}|)(
|-)?))/)[0]…strip
days = []
days_str.scan(/#{$days.keys.join(‘|’)}/) do |day|
days << $days[day]
end
days_str.scan(/(#{$days.keys.join(‘|’)})-(#{$days.keys.join(‘|’)})/)
do
a = $days[$1]
b = $days[$2]
days += (a…(b > a ? b : b+7))…to_a.map{|d|d%7}
end
days = (0…6).to_a if days.empty?
times = []
win.scan(/(\d{4})-(\d{4})/) do
times << (($1.to_i)...($2.to_i))
end
times = [0..2400] if times.empty?
days.each do |d|
times.each do |t|
@times[d] << t
end
end
end
def include?(time)
@times[time.wday].some{|trange| trange ===
(time.hour*100+time.min)}
end
end
end
----- Original Message ----
From: Ruby Q. [email protected]
To: ruby-talk ML [email protected]
Sent: Friday, October 19, 2007 7:14:00 AM
Subject: [QUIZ] Time Window (#144)
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message,
if you can.
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
by Brian C.
Write a Ruby class which can tell you whether the current time (or any
given
time) is within a particular “time window”. Time windows are defined by
strings
in the following format:
# 0700-0900 # every day between these times
# Sat Sun # all day Sat and Sun, no other
times
# Sat Sun 0700-0900 # 0700-0900 on Sat and Sun only
# Mon-Fri 0700-0900 # 0700-0900 on Monday to Friday
only
# Mon-Fri 0700-0900; Sat Sun # ditto plus all day Sat and Sun
# Fri-Mon 0700-0900 # 0700-0900 on Fri Sat Sun Mon
# Sat 0700-0800; Sun 0800-0900 # 0700-0800 on Sat, plus
0800-0900 on Sun
Time ranges should exclude the upper bound, i.e. 0700-0900 is 07:00:00
to
08:59:59. An empty time window means “all times everyday”. Here are
some test
cases to make it clearer:
class TestTimeWindow < Test::Unit::TestCase
def test_window_1
w = TimeWindow.new("Sat-Sun; Mon Wed 0700-0900; Thu 0700-0900
1000-1200")
assert ! w.include?(Time.mktime(2007,9,25,8,0,0)) # Tue
assert w.include?(Time.mktime(2007,9,26,8,0,0)) # Wed
assert ! w.include?(Time.mktime(2007,9,26,11,0,0))
assert ! w.include?(Time.mktime(2007,9,27,6,59,59)) # Thu
assert w.include?(Time.mktime(2007,9,27,7,0,0))
assert w.include?(Time.mktime(2007,9,27,8,59,59))
assert ! w.include?(Time.mktime(2007,9,27,9,0,0))
assert w.include?(Time.mktime(2007,9,27,11,0,0))
assert w.include?(Time.mktime(2007,9,29,11,0,0)) # Sat
assert w.include?(Time.mktime(2007,9,29,0,0,0))
assert w.include?(Time.mktime(2007,9,29,23,59,59))
end
def test_window_2
w = TimeWindow.new("Fri-Mon")
assert ! w.include?(Time.mktime(2007,9,27)) # Thu
assert w.include?(Time.mktime(2007,9,28))
assert w.include?(Time.mktime(2007,9,29))
assert w.include?(Time.mktime(2007,9,30))
assert w.include?(Time.mktime(2007,10,1))
assert ! w.include?(Time.mktime(2007,10,2)) # Tue
end
def test_window_nil
w = RDS::TimeWindow.new("")
assert w.include?(Time.mktime(2007,9,25,1,2,3)) # all times
end
end