Class: Xqsr3::Containers::FrequencyMap

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/xqsr3/containers/frequency_map.rb

Constant Summary collapse

ByElement = 
Class.new do

	def self.[] *args

		fm = FrequencyMap.new

		args.each { |el| fm << el }

		fm
	end

	private_class_method :new
end

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Enumerable

#collect_with_index, #unique

Constructor Details

#initialize ⇒ FrequencyMap

Returns a new instance of FrequencyMap.



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# File 'lib/xqsr3/containers/frequency_map.rb', line 134

def initialize

	@counts	=   {}
	@count	=	0
end

Class Method Details

.[](*args) ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 71

def self.[] *args

	return self.new if 0 == args.length

	if 1 == args.length

		arg = args[0]

		case	arg
		when	::NilClass

			return self.new
		when	::Hash

			fm = self.new
			arg.each do |k, v|

				fm.store k, v
			end
			return fm
		when	::Array

			# accepted forms:
			#
			# 1. Empty array
			# 2. Array exclusively of two-element arrays
			# 3. Array of even number of elements and at every odd index is an integer

			# 1. Empty array

			return self.new if arg.empty?

			# 2. Array exclusively of two-element arrays

			if arg.all? { |el| ::Array === el && 2 == el.size }

				return self.[](::Hash.[]([ *arg ]))
			end

			# 3. Array of even number of elements and at every odd index is an integer

			if (0 == (arg.size % 2)) && arg.each_with_index.select { |el, index| 1 == (index % 2) }.map(&:first).all? { |el| el.kind_of? ::Integer }

				return self.[](::Hash.[](*arg))
			end


			raise ArgumentError, "array parameter not in an accepted form for subscript initialisation"
		else

			return self.[] arg.to_hash if arg.respond_to? :to_hash

			raise TypeError, "given argument is neither a #{::Hash} nor an #{::Array} and does not respond to the to_hash method"
		end

	else

		# treat all other argument permutations as having passed in an array

		return self.[] [ *args ]
	end
end

Instance Method Details

#<<(key) ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 140

def << key

	push key, 1
end

#==(rhs) ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 145

def == rhs

	case	rhs
	when	::NilClass
		return false
	when	::Hash
		return rhs.size == @counts.size && rhs == @counts
	when	self.class
		return rhs.count == self.count && rhs == @counts
	else
		raise TypeError, "can compare #{self.class} only to instances of #{self.class} and #{::Hash}, but #{rhs.class} given"
	end

	false
end

#[](key) ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 161

def [] key

	@counts[key]
end

#[]=(key, count) ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 166

def []= key, count

	store key, count
end

#assoc(key) ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 171

def assoc key

	@counts.assoc key
end

#clear ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 176

def clear

	@counts.clear
	@count = 0
end

#count ⇒ Object

The total number of instances recorded



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# File 'lib/xqsr3/containers/frequency_map.rb', line 183

def count

	@count
end

#default ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 188

def default

	@counts.default
end

#delete(key) ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 193

def delete key

	key_count = @counts.delete key

	@count -= key_count if key_count
end

#dup ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 200

def dup

	fm = self.class.new

	fm.merge! self
end

#each ⇒ Object Also known as: each_pair 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 207

def each

	@counts.each do |k, v|

		yield k, v
	end
end

#each_by_frequency ⇒ Object

Enumerates each entry pair - element + frequency - in descending order of frequency

Note: this method is expensive, as it must create a new dictionary and map all entries into it in order to achieve the ordering



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# File 'lib/xqsr3/containers/frequency_map.rb', line 220

def each_by_frequency

	tm = {}
	@counts.each do |element, frequency|

		if not tm.has_key? frequency

			tm[frequency] = [element]
		else

			tm[frequency].push element
		end
	end

	keys = tm.keys.sort.reverse
	keys.each do |frequency|

		elements = tm[frequency].sort
		elements.each do |element|

			yield element, frequency
		end
	end
end

#each_key ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 245

def each_key

	keys.each do |element|

		yield element
	end
end

#each_value ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 255

def each_value

	keys.each do |element|

		yield @counts[element]
	end
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/xqsr3/containers/frequency_map.rb', line 263

def empty?

	0 == size
end

#eql?(rhs) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/xqsr3/containers/frequency_map.rb', line 268

def eql? rhs

	case	rhs
	when	self.class
		return self == rhs
	else
		return false
	end
end

#fetch(key, default = nil, &block) ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 278

def fetch key, default = nil, &block

	case	default
	when	::NilClass, ::Integer
		;
	else
		raise TypeError, "default parameter ('#{default}') must be of type #{::Integer}, but was of type #{default.class}"
	end

	unless @counts.has_key? key

		return default unless default.nil?

		if block_given?

			case	block.arity
			when	0
				return yield
			when	1
				return yield key
			else
				raise ArgumentError, "given block must take a single parameter - #{block.arity} given"
			end
		end

		raise KeyError, "given key '#{key}' (#{key.class}) does not exist"
	end

	@counts[key]
end

#flatten ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 309

def flatten

	@counts.flatten
end

#has_key?(key) ⇒ Boolean Also known as: include?, key?, member?

Returns:

  • (Boolean) 


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# File 'lib/xqsr3/containers/frequency_map.rb', line 314

def has_key? key

	@counts.has_key? key
end

#has_value?(value) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/xqsr3/containers/frequency_map.rb', line 319

def has_value? value

	case	value
	when	::NilClass, ::Integer
		;
	else
		raise TypeError, "parameter ('#{value}') must be of type #{::Integer}, but was of type #{value.class}"
	end

	@counts.has_value? value
end

#hash ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 331

def hash

	@counts.hash
end

#inspect ⇒ Object Also known as: to_s 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 338

def inspect

	@counts.inspect
end

#key(value) ⇒ Object

def keep_if

@counts.keep_if end



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# File 'lib/xqsr3/containers/frequency_map.rb', line 348

def key value

	case	value
	when	::NilClass, ::Integer
		;
	else
		raise TypeError, "parameter ('#{value}') must be of type #{::Integer}, but was of type #{value.class}"
	end

	@counts.key value
end

#keys ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 362

def keys

	@counts.keys
end

#length ⇒ Object Also known as: size 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 367

def length

	@counts.length
end

#merge(fm) ⇒ Object

Raises:

  • (TypeError) 


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# File 'lib/xqsr3/containers/frequency_map.rb', line 374

def merge fm

	raise TypeError, "parameter must be an instance of type #{self.class}" unless fm.instance_of? self.class

	fm_new = self.class.new

	fm_new.merge! self
	fm_new.merge! fm

	fm_new
end

#merge!(fm) ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 386

def merge! fm

	fm.each do |k, v|

		if not @counts.has_key? k

			@counts[k]	=	v
		else

			@counts[k]	+=	v
		end
		@count += v
	end

	self
end

#push(element, count = 1) ⇒ Object

Raises:

  • (TypeError) 


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# File 'lib/xqsr3/containers/frequency_map.rb', line 403

def push element, count = 1

	raise TypeError, "count ('#{count}') must in an instance of #{::Integer}, but #{count.class} provided" unless count.kind_of? ::Integer

	if not @counts.has_key? element

		@counts[element]	=	count
	else

		@counts[element]	+=	count
	end
	@count += count

	self
end

#shift ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 419

def shift

	r = @counts.shift

	@count -= r[1] if ::Array === r

	r
end

#store(key, value) ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 430

def store key, value

	case	value
	when	::NilClass, ::Integer
		;
	else
		raise TypeError, "value ('#{value}') must be of type #{::Integer}, but was of type #{value.class}"
	end

	key_count = @counts[key] || 0

	@counts.store key, value

	@count += value - key_count
end

#to_a ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 446

def to_a

	@counts.to_a
end

#to_h ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 451

def to_h

	@counts.to_h
end

#to_hash ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 456

def to_hash

	@counts.to_hash
end

#values ⇒ Object 



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# File 'lib/xqsr3/containers/frequency_map.rb', line 463

def values

	@counts.values
end