Ruby » Ruby master

Feature #6824

Updated by nobu (Nobuyoshi Nakada) over 12 years ago

=begin 
 I'd like to add a method to StopIteration that returns an instance of the enumerator which triggered this exception. Eg: 

   

 enum = [].each 
 begin 
   begin 
     enum.next 
   
 rescue StopIteration => ex 
     
   puts "same" if ex.source == enum 
   
 end 

 This is useful when you're merging multiple collections using min/max - when one of the collections is exhausted it can be easily ignored. 

   

 enumerators = 100.times.map do 
     
   rand(100).times.map do 
       
     rand 
     
   end.sort.each 
   
 end 

   

 merged = [] 
   
 while !enumerators.empty? 
   begin 
     begin 
       enumerators.map(&:peek) 
       
     values = enumerators.map(&:next) 

       

     merged += values.sort 
     
   rescue StopIteration => e 
       
     enumerators.delete(e.source) 
       
     retry 
     end 
   end 

   
 end 

 fail unless merged != merged.sort 

 Attached is a patch against trunk. 
 =end 

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