Like Memoize, but designed for mutable and parametizable objects
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clbustos/dirty-memoize
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= dirty-memoize * http://github.com/clbustos/dirty-memoize ==DESCRIPTION Like Memoize, but designed for mutable and parametizable objects Use when: 1. You have one expensive method (\compute) which set many internal variables. So, is preferable lazy evaluation of these dependent variables. 2. The expensive operation depends on one or more parameters 3. Changes on one or more parameters affect all dependent variables 4. You may want to hide the call of 'compute' operation 5. The user could want test several different parameters values == SYNOPSIS By default, the method to compute should be called \#compute. Set constant DIRTY_COMPUTE to the name of other method if you need it Example: require 'dirty-memoize' class Factorial include DirtyMemoize attr_reader :result attr_writer :n dirty_memoize :result dirty_writer :n def initialize @n=nil @result=nil end def fact(n) return 1 if n==1 n*(fact(n-1)) end def compute puts "Computing the factorial!" @result=fact(@n) end end a=Factorial.new a.n=10 puts "Our object is dirty: #{a.dirty?}" puts "The result is: #{a.result}" puts "Our object is no longer dirty: #{a.dirty?}" puts "And the result is cached without calling the compute method: #{a.result}" puts "Now, n is changed to 5" a.n=5 # Object is now dirty. So, compute will be called when we get result puts "The result is: #{a.result}" == Sugestions * Fork, modify and do wathever you need with it. == Copyright Copyright (c) 2010-2011 Claudio Bustos. See LICENSE for details.
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Like Memoize, but designed for mutable and parametizable objects
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