Class: Amazon::Util::LazyResults

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/amazon/util/lazy_results.rb

Overview

This class provides a wrapper for lazy evaluation of results. The constructor takes a block which should accept a pagenumber and return a page worth of results.

Instance Method Summary collapse

Constructor Details

#initialize(&feeder) ⇒ LazyResults

Returns a new instance of LazyResults.



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# File 'lib/amazon/util/lazy_results.rb', line 15

def initialize( &feeder )
  @iterator = PaginatedIterator.new( &feeder )
  flush
end

Instance Method Details

#[](index) ⇒ Object

index into the array set. if requested index has not been loaded, will load up to that index



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# File 'lib/amazon/util/lazy_results.rb', line 33

def []( index )
  feedme while !@iterator.done and index >= @truth.size
  return @truth[index]
end

#each(&block) ⇒ Object

iterate over entire result set, loading lazily



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# File 'lib/amazon/util/lazy_results.rb', line 27

def each( &block ) # :yields: item
  @truth.each {|e| yield e }
  @iterator.each {|e| @truth << e ; yield e }
end

#flush ⇒ Object

clear the result set and start over again



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# File 'lib/amazon/util/lazy_results.rb', line 21

def flush
  @truth = []
  @iterator.restart
end

#inspect ⇒ Object

:nodoc:



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# File 'lib/amazon/util/lazy_results.rb', line 44

def inspect # :nodoc:
  "#<Amazon::Util::LazyResults truth_size=#{@truth.size} page=#{@page} done=#{@done}>"
end

#to_a ⇒ Object

fully populate the result set and return a true array



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# File 'lib/amazon/util/lazy_results.rb', line 39

def to_a
  feedme until @iterator.done
  return @truth.dup
end