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 135

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 63

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 175

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 144

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 159

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 193

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 199

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 205

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 214

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 226

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 246

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 255

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 265

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 274

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 289

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 303

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 310

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 325

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 373

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 396

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 405

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 422

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 438

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 471

def length

  @inner.size
end

#merge(other) ⇒ Object

See #merge



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# File 'lib/xqsr3/containers/multi_map.rb', line 584

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 596

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 487

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 507

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 619

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 628

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 638

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 540

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 560

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 644

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 650

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 656

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 662

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 668

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 678

def values_unflattened

  @inner.values
end