Bug #276: take_while functions inconsistently

• Status: Rejected
• Assignee: -

=begin
take_while didn't work at all until 1.8.7 - I assume that is how it supposed to be. Perhaps that explains some of this behavior, too?

cards is an Array of Cards

pp cards:
[#<Card:0x179094 @suit="C", @value=4>,
#<Card:0x1793b4 @suit="C", @value=3>,
#<Card:0x177dd4 @suit="C", @value=10>,
#<Card:0x177500 @suit="D", @value=13>,
#<Card:0x1771e0 @suit="D", @value=14>,
#<Card:0x1770c8 @suit="S", @value=14>,
#<Card:0x177794 @suit="C", @value=12>]

suit = 'C'
cards = cards.take_while { |this_card| this_card.suit == suit }:
[#<Card:0x179094 @suit="C", @value=4>,
#<Card:0x1793b4 @suit="C", @value=3>,
#<Card:0x177dd4 @suit="C", @value=10>]

Note that #<Card:0x177794 @suit="C", @value=12> is not contained in the take_while although it is also 'C' for the suit.
For some reason, it also does not group the 4th 'C' together when sorted:

def sortBySuit( cards = nil )
if ! cards
cards = @hand_check_cards
end

 cards = cards.sort_by { |card| card.suit }    

end

self.sortBySuit( cards )

So we try to grab another suit:

suit = 'S'
cards = cards.take_while { |this_card| this_card.suit == suit }:
[]

We end up with nothing.

Here is the Card class.

#!/usr/bin/env ruby

class Card

attr_accessor :value, :suit

@value
@suit

def initialize( value, suit )
if value.is_a?(String)
@value = value.to_i
else
@value = value
pp value
pp 'goda'
exit
end
@suit = suit.to_s
end

def name

 case @value
   when 2 
     name = "2"
   when 3    
     name = "3"      
   when 4    
     name = "4"      
   when 5    
     name = "5"      
   when 6    
     name = "6"      
   when 7    
     name = "7"      
   when 8    
     name = "8"      
   when 9    
     name = "9"      
   when 10   
     name = "10"       
   when "T"    
     name = "10"
   when 11 # Jack
     name = "J"       
   when 12 # Queen
     name = "Q"       
   when 13 # King
     name = "K"       
   when 14 # Ace
     name = "A"      
 end
 return name + @suit

end

def next
if @value == 14
return 2
else
return @value + 1
end
end

def prev
if @value == 2
return 14
else
return @value - 1
end
end

end

and here is where the Cards are initialized with their suits:
def initCards()
13.times do |this_time|
index = this_time + 2
@cards[index.to_s + 'D'] = Card.new( index.to_s, 'D' )
@cards[index.to_s + 'C'] = Card.new( index.to_s, 'C' )
@cards[index.to_s + 'S'] = Card.new( index.to_s, 'S' )
@cards[index.to_s + 'H'] = Card.new( index.to_s, 'H' )
@card_index.push( index.to_s + 'C' )
@card_index.push( index.to_s + 'H' )
@card_index.push( index.to_s + 'S' )
@card_index.push( index.to_s + 'D' )
end
end

Am I doing something wrong? This seems like a bug.

Asher ([e-mail])
=end

[mboeh (Matthew Boeh)]

=begin
Your sortBySuit method appears to be doing nothing, because it's just assigning the sorted result to a local variable which is subsequently discarded. You might want to try

cards.replace(cards.sort_by {|card| card.suit })

Enumerable#take_while is behaving properly in your first case:

"Passes elements to the block until the block returns nil or false, then stops iterating and returns an array of all prior elements."

That is, since your fourth card has suit == "D", #take_while stops at that point and never gets to your last card.

In any case, the behavior you appear to be expecting is provided by Enumerable#select, not Enumerable#take_while.
=end

[shyouhei (Shyouhei Urabe)]

• Status changed from Open to Rejected

=begin

=end