Splitting up of a certain method into two not working (for me)

Michael_Schwarze · 14 June 2016 14:51

Hi,

I’ve got a problem with splitting up my below stated method into two. I’m on Ruby 2.3.1 using the Holidays Gem, but I think this is probably more related to me not spotting the obvious

The following implementation works correctly, producing 21 business days for December 2016 (in Germany), for instance:

···

~~~
require 'date'
require 'holidays'

class DateOperations
  def self.number_of_business_days_between(start_date, end_date)
    week_days = week_days_between(start_date, end_date)
    business_days = []
    week_days.each do |b|
      business_days << b unless holiday?(b)
    end
    business_days.length
  end

  def self.week_days_between(start_date, end_date)
    week_day_nbrs = (1..5)
    (start_date..end_date).select { |w| week_day_nbrs.include?(w.wday) }
  end

  def self.holiday?(date)
    return false if Holidays.on(date, :de, :informal).empty?
    true
  end
end
~~~

When delegating gathering of the array with the business days to another method, everything else staying the same, number_of_business_days_between results in 22 for December 2016 in Germany instead of 21:

~~~
  def self.number_of_business_days_between(start_date, end_date)
    business_days = business_days_between(start_date, end_date)
    business_days.length
  end

  def self.business_days_between(start_date, end_date)
    week_days = week_days_between(start_date, end_date)
    business_days = []
    week_days.each do |b|
      business_days << b unless holiday?(b)
    end
  end
~~~

From my point of view both implementations of number_of_business_days_between should work exactly the same, unfortunately not for me - any ideas on this?

Many thanks!

Cheers,
Michael

Michael_Fellinger1 · 14 June 2016 14:56

Your `def self.business_days_between(start_date, end_date)` must return
`business_days.length`, right now it returns `week_days` instead.

···

On 14 June 2016 at 16:52:12, Michael Schwarze (michael@schwarze-web.de) wrote:

Hi,

I’ve got a problem with splitting up my below stated method into two. I’m
on Ruby 2.3.1 using the Holidays Gem, but I think this is probably more
related to me not spotting the obvious

The following implementation works correctly, producing 21 business days
for December 2016 (in Germany), for instance:

~~~
require 'date'
require 'holidays'

class DateOperations
def self.number_of_business_days_between(start_date, end_date)
week_days = week_days_between(start_date, end_date)
business_days = []
week_days.each do |b|
business_days << b unless holiday?(b)
end
business_days.length
end

def self.week_days_between(start_date, end_date)
week_day_nbrs = (1..5)
(start_date..end_date).select { |w| week_day_nbrs.include?(w.wday) }
end

def self.holiday?(date)
return false if Holidays.on(date, :de, :informal).empty?
true
end
end
~~~

When delegating gathering of the array with the business days to another
method, everything else staying the same, number_of_business_days_between
results in 22 for December 2016 in Germany instead of 21:

~~~
def self.number_of_business_days_between(start_date, end_date)
business_days = business_days_between(start_date, end_date)
business_days.length
end

def self.business_days_between(start_date, end_date)
week_days = week_days_between(start_date, end_date)
business_days = []
week_days.each do |b|
business_days << b unless holiday?(b)
end
end
~~~

From my point of view both implementations of
number_of_business_days_between should work exactly the same, unfortunately
not for me - any ideas on this?

Many thanks!

Cheers,
Michael

Jesus_Gabriel_y_Gala · 14 June 2016 15:01

It should actually return business_days. But I think there's a cleaner
implementation:

def self.business_days_between(start_date, end_date)
week_days = week_days_between(start_date, end_date)
week_days.reject {|b| holiday?(b) }
end

The intermediate array is managed by the reject method for you.

Jesus.

···

On Tue, Jun 14, 2016 at 4:56 PM, Michael Fellinger <m.fellinger@gmail.com> wrote:

Your `def self.business_days_between(start_date, end_date)` must return
`business_days.length`, right now it returns `week_days` instead.

Michael_Schwarze · 14 June 2016 16:48

Michael

Thanks, that was the point I was missing; the block given to week_day.each of course does not get returned!

Cheers,
Michael

···

Am 14.06.2016 um 16:56 schrieb Michael Fellinger <m.fellinger@gmail.com>:

Your `def self.business_days_between(start_date, end_date)` must return `business_days.length`, right now it returns `week_days` instead.

On 14 June 2016 at 16:52:12, Michael Schwarze (michael@schwarze-web.de) wrote:

Hi,

I’ve got a problem with splitting up my below stated method into two. I’m on Ruby 2.3.1 using the Holidays Gem, but I think this is probably more related to me not spotting the obvious

The following implementation works correctly, producing 21 business days for December 2016 (in Germany), for instance:

~~~
require 'date'
require 'holidays'

class DateOperations
def self.number_of_business_days_between(start_date, end_date)
week_days = week_days_between(start_date, end_date)
business_days = []
week_days.each do |b|
business_days << b unless holiday?(b)
end
business_days.length
end

def self.week_days_between(start_date, end_date)
week_day_nbrs = (1..5)
(start_date..end_date).select { |w| week_day_nbrs.include?(w.wday) }
end

def self.holiday?(date)
return false if Holidays.on(date, :de, :informal).empty?
true
end
end
~~~

When delegating gathering of the array with the business days to another method, everything else staying the same, number_of_business_days_between results in 22 for December 2016 in Germany instead of 21:

~~~
def self.number_of_business_days_between(start_date, end_date)
business_days = business_days_between(start_date, end_date)
business_days.length
end

def self.business_days_between(start_date, end_date)
week_days = week_days_between(start_date, end_date)
business_days = []
week_days.each do |b|
business_days << b unless holiday?(b)
end
end
~~~

From my point of view both implementations of number_of_business_days_between should work exactly the same, unfortunately not for me - any ideas on this?

Many thanks!

Cheers,
Michael

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Michael Schwarze

Michael_Schwarze · 14 June 2016 19:05

Jesus

Thanks a lot to you, too! I can see my mistake now; that’s why I’m a friend of explicit returns I really like your cleaner approach.

Cheers,
Michael

···

Am 14.06.2016 um 17:01 schrieb Jesús Gabriel y Galán <jgabrielygalan@gmail.com>:

On Tue, Jun 14, 2016 at 4:56 PM, Michael Fellinger > <m.fellinger@gmail.com> wrote:

Your `def self.business_days_between(start_date, end_date)` must return
`business_days.length`, right now it returns `week_days` instead.

It should actually return business_days. But I think there's a cleaner
implementation:

def self.business_days_between(start_date, end_date)
week_days = week_days_between(start_date, end_date)
week_days.reject {|b| holiday?(b) }
end

The intermediate array is managed by the reject method for you.

Jesus.

Unsubscribe: <mailto:ruby-talk-request@ruby-lang.org?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-talk>

Mit freundlichem Gruß
Michael Schwarze