From: Adam Akhtar <adamtemporary@...>
Date: 2008-08-24T21:03:37+09:00
Subject: defining sort <=> for a class

If i have a class

class Example

attr_accessor :value

def initialize
    @value = 0
end


end

and I have an array of examples and want to sort them based on value how
do i define a <=> for my class. I know its possible as it was a side
comment on an  earlier post. Seeing as this is a totally different
subject to that post i decided to ask in a new post - it will be easier
for others who may have the same questoin to search for.

i tried this

class Example

attr_accessor :value

def initialize
    @value = 0
end

def <=>(other_example)
   @value <=> other_example
end
end

but i keep getting an error of undefined method for nill class when i
try to call it like this with an array of example objects

ojects.sort do |one, another|
   one.<=>(another)
end

i also tried
ojects.sort do |one, another|
   one <=>(another)
end

(i.e no period between one and <=>)

where am i going wrong???
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