Class: Xqsr3::Containers::MultiMap

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

Overview

Hash-like class that stores as mapped values in arrays

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Enumerable

#collect_with_index, #detect_map, #unique

Methods inherited from Hash

#except, #except!, #has_match?, #match, #slice

Methods included from HashUtilities::DeepTransform

#deep_transform, #deep_transform!

Constructor Details

#initialize ⇒ MultiMap

Initialises an instance



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

def initialize

	@merge_is_multi = true

	@inner	=	Hash.new
end

Class Method Details

.[](*args) ⇒ Object

Creates an instance from the given arguments



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# File 'lib/xqsr3/containers/multi_map.rb', line 62

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

			mm = self.new

			arg.each do |k, v|

				raise ArgumentError, "mapped elements in hashes must be arrays, #{v.class} given" unless v.kind_of? ::Array

				mm.store k, *v
			end

			return mm
		when	::Array

			# accepted forms:
			#
			# 1. Empty array
			# 2. Array exclusively of arrays

			# 1. Empty array

			return self.new if arg.empty?

			# 2. Array exclusively of arrays

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

				h = Hash.new { |hash, key| hash[key] = [] }

				arg.each do |ar|

					raise ArgumentError, "cannot pass an empty array in array of arrays initialiser" if ar.empty?

					key = ar.shift

					ar.each { |value| h[key] << value }
				end

				return self.[](h)
			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

#==(rhs) ⇒ Object

Compares the instance for equality against rhs

  • Parameters:

    • rhs (nil, ::Hash, MultiMap) The instance to compare against

  • Exceptions:

    • ::TypeError if rhs is not of the required type(s)



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# File 'lib/xqsr3/containers/multi_map.rb', line 174

def == rhs

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

	false
end

#[](key) ⇒ Object

Obtains the values, if any, for the given key; returns nil if no values are stored



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# File 'lib/xqsr3/containers/multi_map.rb', line 143

def [] key

	return @inner[key]
end

#[]=(key, values) ⇒ Object

Adds/assigns a new key+values pair. Equivalent to

store(key, *values)

  • Parameters:

    • key The element key

    • values (Array) The values to be associated with the key

  • Exceptions:

    • ::TypeError if values is not an array

Raises:

  • (TypeError) 


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# File 'lib/xqsr3/containers/multi_map.rb', line 158

def []= key, values

	values = [] if values.nil?

	raise TypeError, "values must be an array, but #{values.class} given" unless values.kind_of? ::Array

	store key, *values
end

#assoc(key) ⇒ Object

Searches the instance comparing each element with key, returning the mapped values array if found, or nil if not



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# File 'lib/xqsr3/containers/multi_map.rb', line 192

def assoc key

	@inner.assoc key
end

#clear ⇒ Object

Removes all elements from the instance



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# File 'lib/xqsr3/containers/multi_map.rb', line 198

def clear

	@inner.clear
end

#count ⇒ Object

The total number of instances recorded



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# File 'lib/xqsr3/containers/multi_map.rb', line 204

def count

	@inner.each_value.map { |ar| ar.size}.inject(0, :+)
end

#delete(key) ⇒ Object

Deletes all values mapped with the given key

  • Parameters:

    • key The key to delete



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# File 'lib/xqsr3/containers/multi_map.rb', line 213

def delete key

	@inner.delete key
end

#each(*defaults) ⇒ Object

Calls block once for each key-value pair, passing the key and each of its values in turn. If the values for a given key are empty and defaults is not empty, the block is invoked for that key (with defaults[0]) once

  • Exceptions:

    • ArgumentError if more than 1 defaults is provided, or no block is given

Raises:

  • (ArgumentError) 


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# File 'lib/xqsr3/containers/multi_map.rb', line 225

def each *defaults

	raise ArgumentError, "may only supply 0 or 1 defaults" if defaults.size > 1
	raise ArgumentError, 'block is required' unless block_given?

	@inner.each do |key, values|

		if values.empty? && !defaults.empty?

			yield key, defaults[0]

			next
		end

		values.each { |value| yield key, value }
	end
end

#each_key ⇒ Object

Calls block once for each key in the instance, passing the key. If no block is provided, an enumerator is returned



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

def each_key

	return @inner.each_key unless block_given?

	@inner.each_key { |key| yield key }
end

#each_unflattened ⇒ Object

Calls block once for each key-values pair, passing the key and its values array. If no block is provided, an enumerator is returned



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# File 'lib/xqsr3/containers/multi_map.rb', line 254

def each_unflattened

	return @inner.each unless block_given?

	@inner.each { |key, value| yield key, value }
end

#each_unflattened_with_index ⇒ Object

Calls block once for each key-values pair, passing the key and its values array and a key index. If no block is provided, an enumerator is returned



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# File 'lib/xqsr3/containers/multi_map.rb', line 264

def each_unflattened_with_index

	return @inner.each_with_index unless block_given?

	@inner.each_with_index { |kv, index| yield kv, index }
end

#each_value ⇒ Object

Calls block once for each value in the instance, passing the value. If no block is provided, an enumerator is returned



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# File 'lib/xqsr3/containers/multi_map.rb', line 273

def each_value

	return @inner.each_value unless block_given?

	@inner.each do |key, values|

		values.each { |value| yield value }
	end
end

#each_with_index ⇒ Object

Calls block once for each key-values, passing the key and each of its values and a value index

  • Exceptions:

    • ArgumentError if no block is given

Raises:

  • (ArgumentError) 


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# File 'lib/xqsr3/containers/multi_map.rb', line 288

def each_with_index

	raise ArgumentError, 'block is required' unless block_given?

	index = 0
	self.each do |key, value|

		yield key, value, index

		index += 1
	end
end

#empty? ⇒ Boolean

Returns true if instance contains no elements; false otherwise

Returns:

  • (Boolean) 


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# File 'lib/xqsr3/containers/multi_map.rb', line 302

def empty?

	@inner.empty?
end

#eql?(rhs) ⇒ Boolean

Returns true if rhs is an instance of MultiMap and contains the same elements and their counts; false otherwise

Returns:

  • (Boolean) 


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

def eql? rhs

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

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

Returns the values associated with the given key

  • Parameters:

    • key The key

    • default The default value



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# File 'lib/xqsr3/containers/multi_map.rb', line 324

def fetch key, default = (default_parameter_defaulted_ = true; nil), &block

	unless default_parameter_defaulted_

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

	unless @inner.has_key? key

		return default unless default_parameter_defaulted_

		if block_given?

			r = nil

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

			case	r
			when	::Array
				;
			else
				raise ArgumentError, "given block must return a value of type #{::Array} or one convertible implicitly to such" unless r.respond_to? :to_ary

				r = r.to_ary
			end

			return r
		end

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

	@inner.fetch key
end

#flatten ⇒ Object

Returns the equivalent flattened form of the instance



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# File 'lib/xqsr3/containers/multi_map.rb', line 372

def flatten

	r = []

	@inner.each do |key, values|

		if values.empty?

			r << key << []
		else

			values.each do |value|

				r << key << value
			end
		end
	end

	r
end

#has_key?(key) ⇒ Boolean

Returns true if an element with the given key is in the map; false otherwise

Returns:

  • (Boolean) 


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# File 'lib/xqsr3/containers/multi_map.rb', line 395

def has_key? key

	@inner.has_key? key
end

#has_value?(value) ⇒ Boolean

Returns true if any key has the given value; false otherwise

  • Parameters:

    • value The value for which to search

Returns:

  • (Boolean) 


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# File 'lib/xqsr3/containers/multi_map.rb', line 404

def has_value? value

	@inner.each do |k, vals|

		return true if vals.include? value
	end

	false
end

#has_values?(values) ⇒ Boolean

Returns true if any key has the given values; false otherwise

  • Parameters:

    • values (Array) The values for which to search

  • Exceptions:

    • ::TypeError if value is not an Array

Returns:

  • (Boolean)

Raises:

  • (TypeError) 


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# File 'lib/xqsr3/containers/multi_map.rb', line 421

def has_values? values

	raise TypeError, "'values' parameter must be of type #{::Array}" unless Array === values

	@inner.has_value? values
end

#key(*values) ⇒ Object

Returns the key for the given value(s)

  • Parameters:

    • values (Array) The value(s) for which to search

If a single value is specified, the entries in the instance are searched first for an exact match to all (1) value(s); if that fails, then the first key with a values containing the given value is returned



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# File 'lib/xqsr3/containers/multi_map.rb', line 437

def key *values

	case values.size
	when 0

		return nil
	when 1

		i = nil

		@inner.each do |k, vals|

			return k if vals == values

			if i.nil?

				i = k if vals.include? values[0]
			end
		end

		return i
	else

		@inner.each do |key, vals|

			return key if vals == values
		end

		return nil
	end
end

#length ⇒ Object Also known as: size

The number of elements in the map



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# File 'lib/xqsr3/containers/multi_map.rb', line 470

def length

	@inner.size
end

#merge(other) ⇒ Object

See #merge



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# File 'lib/xqsr3/containers/multi_map.rb', line 583

def merge other

	if @merge_is_multi

		multi_merge other
	else

		strict_merge other
	end
end

#merge!(other) ⇒ Object

See #merge!



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# File 'lib/xqsr3/containers/multi_map.rb', line 595

def merge! other

	if @merge_is_multi

		multi_merge! other
	else

		strict_merge! other
	end
end

#multi_merge(other) ⇒ Object

Returns a new instance containing a merging of the current instance and the other instance

NOTE: where any key is found in both merging instances the values resulting will be a concatenation of the sets of values

  • Parameters:

    • other (MultiMap, Hash) The instance from which to merge

  • Exceptions:

    • TypeError Raised if other is not a MultiMap or a Hash



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# File 'lib/xqsr3/containers/multi_map.rb', line 486

def multi_merge other

	mm = self.class.new

	mm.merge! self
	mm.merge! other

	mm
end

#multi_merge!(other) ⇒ Object

Merges the contents of other into the current instance

NOTE: where any key is found in both merging instances the values resulting will be a concatenation of the sets of values

  • Parameters:

    • other (MultiMap, Hash) The instance from which to merge

  • Exceptions:

    • TypeError Raised if other is not a MultiMap or a Hash



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# File 'lib/xqsr3/containers/multi_map.rb', line 506

def multi_merge! other

	case other
	when self.class

		;
	when ::Hash

		;
	else

		raise TypeError, "parameter must be an instance of #{self.class} or #{Hash}"
	end

	other.each do |k, v|

		self.push k, v
	end

	self
end

#push(key, *values) ⇒ Object

Pushes the given key and values. If the key is already in the map then the values will be concatenated with those already present

Signature

  • Parameters:

    • key The element key

    • values (*Array) The value(s) to be pushed

Exceptions

- +::RangeError+ raised if the value of +count+ results in a negative count for the given element
- +::TypeError+ if +count+ is not an +::Integer+



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# File 'lib/xqsr3/containers/multi_map.rb', line 618

def push key, *values

	@inner[key] = [] unless @inner.has_key? key

	@inner[key].push(*values)
end

#shift ⇒ Object

Removes a key-value pair from the instance and return as a two-item array



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# File 'lib/xqsr3/containers/multi_map.rb', line 627

def shift

	@inner.shift
end

#store(key, *values) ⇒ Object

Causes an element with the given key and values to be stored. If an element with the given key already exists, its values will b replaced



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# File 'lib/xqsr3/containers/multi_map.rb', line 637

def store key, *values

	@inner[key] = values
end

#strict_merge(other) ⇒ Object

Returns a new instance containing a merging of the current instance and the other instance

NOTE: where any key is found in both merging instances the values from other will be used

  • Parameters:

    • other (MultiMap, Hash) The instance from which to merge

  • Exceptions:

    • TypeError Raised if other is not a MultiMap or a Hash



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# File 'lib/xqsr3/containers/multi_map.rb', line 539

def strict_merge other

	mm = self.class.new

	mm.strict_merge! self
	mm.strict_merge! other

	mm
end

#strict_merge!(other) ⇒ Object

Merges the contents of other into the current instance

NOTE: where any key is found in both merging instances the values from other will be used

  • Parameters:

    • other (MultiMap, Hash) The instance from which to merge

  • Exceptions:

    • TypeError Raised if other is not a MultiMap or a Hash



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# File 'lib/xqsr3/containers/multi_map.rb', line 559

def strict_merge! other

	case other
	when self.class

		other.each_unflattened do |k, vals|

			self.store k, *vals
		end
	when ::Hash

		other.each do |k, v|

			self.store k, v
		end
	else

		raise TypeError, "parameter must be an instance of #{self.class} or #{Hash}"
	end

	self
end

#to_a ⇒ Object

Converts instance to an array of [key,value] pairs



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# File 'lib/xqsr3/containers/multi_map.rb', line 643

def to_a

	self.flatten
end

#to_h ⇒ Object

Obtains reference to internal hash instance (which must not be modified)



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# File 'lib/xqsr3/containers/multi_map.rb', line 649

def to_h

	@inner.to_h
end

#to_hash ⇒ Object

Obtains equivalent hash to instance



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# File 'lib/xqsr3/containers/multi_map.rb', line 655

def to_hash

	@elements.to_hash
end

#to_s ⇒ Object

A string-form of the instance



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# File 'lib/xqsr3/containers/multi_map.rb', line 661

def to_s

	@inner.to_s
end

#values ⇒ Object

An array of all values in the instance



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# File 'lib/xqsr3/containers/multi_map.rb', line 667

def values

	r	=	[]

	@inner.values.each  { |vals| r += vals }

	r
end

#values_unflattened ⇒ Object

An array of all sets of values in the instance



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# File 'lib/xqsr3/containers/multi_map.rb', line 677

def values_unflattened

	@inner.values
end