Sha256: 6a13e36e675251a2a84457dc518fcc71fd8be05ee6d59639d3850111d2a04432
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Size: 944 Bytes
Versions: 8
Compression:
Stored size: 944 Bytes
Contents
module Enumerable
# Returns all items that are equal in terms of the supplied block.
# If no block is given objects are considered to be equal if they
# return the same value for Object#hash and if obj1 == obj2.
#
# [1, 2, 2, 3, 4, 4].commonality # => { 2 => [2], 4 => [4] }
#
# ["foo", "bar", "a"].commonality { |str| str.length }
# # => { 3 => ["foo, "bar"] }
#
# # Returns all persons that share their last name with another person.
# persons.collisions { |person| person.last_name }
#
# CREDIT: Florian Gross
def commonality( &block )
had_no_block = !block
block ||= lambda { |item| item }
result = Hash.new { |hash, key| hash[key] = Array.new }
self.each do |item|
key = block.call(item)
result[key] << item
end
result.reject! do |key, values|
values.size <= 1
end
#return had_no_block ? result.values.flatten : result
return result
end
end
Version data entries
8 entries across 8 versions & 1 rubygems