Multiset library for Ruby

[Japanese]

Ruby implementation of multiset. Unlike ordinary set(see Ruby documentation for "set" library), multiset can store two or more same items.

Set[:a,:b,:c,:b,:b,:c] # => #<Set: {:b, :c, :a}>
Multiset[:a,:b,:c,:b,:b,:c] # => #<Multiset:#3 :b, #2 :c, #1 :a>

Multisets are typically used for counting elements and their numbers of appearances in collections.

# Counting the appearances of characters in a string
# (Ruby 1.8.7 or later)
Multiset.new("abracadabra".each_char)
# => #<Multiset:#5 "a", #2 "b", #2 "r", #1 "c", #1 "d">

# The same
m = Multiset.new
"abracadabra".each_char do |c| # replace with 'each_byte' in Ruby 1.8.6 or before
  m << c
end
p m
# => #<Multiset:#5 "a", #2 "b", #2 "r", #1 "c", #1 "d">

# The same but works with Ruby 1.8.6 or before
Multiset.new("abracadabra".split(//))
# => #<Multiset:#5 "a", #2 "b", #2 "r", #1 "c", #1 "d">

Modified Specifications

Other Major Updates

Install/Download

The library is available via Rubygems. Use the command

gem install multiset

.gem file is available at http://rubygems.org/gems/multiset.

Source codes are available at http://github.com/maraigue/multiset. You can fork or propose fixes on the library via Git.

[Old versions]

*This program is distributed under MIT License (0.3.* or after) / BSD license (0.2.* or before).

Document

Ver. 0.4.* Ver. 0.2.* Ver. 0.132

[Reverse reference] (Added on 2008/3/1)

Contact

email to main(at-mark)hhiro.net .


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