generate a seed (BigInt) from an arbitrary string

seed.rb

require 'digest'

class String
  def to_seed
    (Digest::SHA256.hexdigest(self).to_i(16))
  end
end

puts "abc".to_seed => 84342368487090800366523834928142263660104883695016514377462985829716817089965
puts "123123123".to_seed => 66573445395556389320569794094825521729047035552620196053537129277119858926575