Sha256: c3362693f37aeac79cef60ae11ebcd4126a7371b51ca023e7cb40be2c9246586
Contents?: true
Size: 1 KB
Versions: 7
Compression:
Stored size: 1 KB
Contents
module Enumerable
# Returns an array of elements for the elements that occur n times.
# Or according to the results of a given block.
#
# a = [1,1,2,3,3,4,5,5]
#
# a.occur(1).sort #=> [2,4]
# a.occur(2).sort #=> [1,3,5]
# a.occur(3).sort #=> []
#
# a.occur(1..1).sort #=> [2,4]
# a.occur(2..3).sort #=> [1,3,5]
#
# a.occur { |n| n == 1 }.sort #=> [2,4]
# a.occur { |n| n > 1 }.sort #=> [1,3,5]
#
def occur(n=nil) #:yield:
result = Hash.new { |hash, key| hash[key] = Array.new }
self.each do |item|
key = item
result[key] << item
end
if block_given?
result.reject! { |key, values| ! yield(values.size) }
else
raise ArgumentError unless n
if Range === n
result.reject! { |key, values| ! n.include?(values.size) }
else
result.reject! { |key, values| values.size != n }
end
end
return result.values.flatten.uniq
end
end
Version data entries
7 entries across 6 versions & 1 rubygems