From: Todd Benson <caduceass@...>
Date: 2008-03-01T18:03:46+09:00
Subject: Re: making a monthly calendar...

On Sat, Mar 1, 2008 at 2:34 AM, Mikkel Bruun <mikkel@helenius.dk> wrote:
> Todd Benson wrote:
>  > On Fri, Feb 29, 2008 at 4:30 PM, Mikkel Bruun <mikkel@helenius.dk>
>  > wrote:
>
> >>  5. week i need to show march 1 and 2  and the same in the front...
>  >>
>
> >>  mikkel
>  >
>  > Here's one for fun.  I'm pretty sure you don't want to use this (for
>  > all I know, you might be laughed out of the room :), but it
>  > demonstrates some methods...
>  >
>   woot, it actually works....
>
>  ive been doing ruby since 2000 but i cant undestand what the h*ll going
>  on there....
>
>  can you give me a walkthrough or a more humane rewrite ;-)

Okay, changing the code...

<CODE>

require 'enumerator'
# I need that for the each_slice method later
today = Date.today
offset = today.wday
# gives me the day of the week
months_of_concern = (-1..1).inject([]) {|arr, i| arr << (today.month + i)}
# just running through -1 to 1 and adding to the current month
# it gives you last month, current month, and next month numbers
# which will be handed to months_of_concern after the block finishes
month_ranges = months_of_concern.map {|month| 1..Date.new( today.year,
month, -1 ).day}
# building ranges to later turn into arrays
# you get previous, current, and future month ranges
# the month days
# -1 is used, as Morton so excellently pointed out
# as the _last_ number
# this is common in Ruby

day_sets = month_ranges.map {|i| i.to_a}
# turning the Range objects (3 of them) into Array objects
# I should have used {|i| i.map} here because it
# would have been cuter, which is mostly disapproved
# of in production code :)

offset.times { day_sets[1].unshift day_sets[0].pop }
# Here, we're just moving the last numbers of the last
# month to the first part of this month one by one

day_sets[1..2].flatten.slice(0..35).compact.each_slice(7) {|i| p i}
# This one is actually easy to understand.
# Grab what we now have as the current month,
# tap on the ending month,
# flatten it (turn it into one big array),
# slice off the numbers that are in slots 0 to 35
# compact (there might be nils)
# each_slice simply builds arrays by
# grabbing things 7 at a time.

</CODE>

Keep in mind scope.  The "i" variable is local to each block; all by
himself.  It doesn't have to be "i", also.

Todd