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# File 'lib/join-iterator.rb', line 1
def join_sorted(iterators)
iterators = iterators.map(&:to_enum)
values = []
keys = []
iterators.each_with_index do |iterator, index|
begin
kv = iterator.next
values[index] = kv[1]
keys[index] = kv[0]
rescue StopIteration
values[index] = nil
keys[index] = nil
iterators[index] = nil
end
end
until iterators.map{|x| x == nil}.all?
line = []
min_key = keys.select{|x| x != nil }.min
keys.each_with_index do |key, index|
if key == min_key
line << values[index]
begin
kv = iterators[index].next
values[index] = kv[1]
keys[index] = kv[0]
rescue StopIteration
values[index] = nil
keys[index] = nil
iterators[index] = nil
end
else
line << nil
end
end
yield [min_key, line]
end
end
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