A 5 minute implementation of facets on Picky.

facets.rb

# Run using
#   ruby facets.rb
#
require 'picky'

# Define index.
#
data = Picky::Index.new :models do
  category :id
  category :name
  category :surname
end

# Add data.
#
data.replace_from id: 1, name: 'Picky',     surname: 'McNamara'
data.replace_from id: 2, name: 'Florian',   surname: 'Hanke'
data.replace_from id: 3, name: 'Tentacles', surname: 'Jellyfish'
data.replace_from id: 4, name: 'Tentacles', surname: 'Florian'
data.replace_from id: 5, name: 'Florian',   surname: 'Tentacles'

# Look facets up in the index.
#
puts data[:name].exact.inverted.map { |name, ids|
  [name, ids.size]
}

# Add convenience method.
#
class Picky::Index
  
  def facets category
    self[category].exact.inverted.inject({}) { |result, token_ids|
      token, ids = token_ids
      result[token] = ids.size
      result
    }
  end
  
end

# Use convenience method.
#
puts data.facets :name    # => {"picky"=>1, "florian"=>2, "tentacles"=>2}
puts data.facets :surname # => {"mcnamara"=>1, "hanke"=>1, "jellyfish"=>1, "florian"=>1, "tentacles"=>1}

# Query generation.
#
puts "Queries: (with original query 'something')"
queries = data.facets(:name).map do |token, _|
  "name:#{token} something"
end
puts queries