Class Dictionary
In: lib/more/facets/dictionary.rb
Parent: Object

Dictionary

The Dictionary class is a Hash that preserves order. So it has some array-like extensions also. By defualt a Dictionary object preserves insertion order, but any order can be specified including alphabetical key order.

Usage

Just require this file and use Dictionary instead of Hash.

  # You can do simply
  hsh = Dictionary.new
  hsh['z'] = 1
  hsh['a'] = 2
  hsh['c'] = 3
  p hsh.keys     #=> ['z','a','c']

  # or using Dictionary[] method
  hsh = Dictionary['z', 1, 'a', 2, 'c', 3]
  p hsh.keys     #=> ['z','a','c']

  # but this don't preserve order
  hsh = Dictionary['z'=>1, 'a'=>2, 'c'=>3]
  p hsh.keys     #=> ['a','c','z']

  # Dictionary has useful extensions: push, pop and unshift
  p hsh.push('to_end', 15)       #=> true, key added
  p hsh.push('to_end', 30)       #=> false, already - nothing happen
  p hsh.unshift('to_begin', 50)  #=> true, key added
  p hsh.unshift('to_begin', 60)  #=> false, already - nothing happen
  p hsh.keys                     #=> ["to_begin", "a", "c", "z", "to_end"]
  p hsh.pop                      #=> ["to_end", 15], if nothing remains, return nil
  p hsh.keys                     #=> ["to_begin", "a", "c", "z"]
  p hsh.shift                    #=> ["to_begin", 30], if nothing remains, return nil

Usage Notes

  • You can use order_by to set internal sort order.
  • #<< takes a two element [k,v] array and inserts.
  • Use ::auto which creates Dictionay sub-entries as needed.
  • And ::alpha which creates a new Dictionary sorted by key.

Methods

<<   ==   []   []   []=   alpha   auto   clear   delete   delete_if   dup   each   each_key   each_pair   each_value   empty?   fetch   first   has_key?   insert   inspect   invert   key?   keys   last   length   merge   merge!   new   new_by   order   order_by   order_by_key   order_by_value   pop   push   reject   reject!   reorder   replace   reverse   reverse!   select   shift   size   store   to_a   to_h   to_hash   to_s   unshift   update   values  

Included Modules

Enumerable

Public Class methods

[Source]

# File lib/more/facets/dictionary.rb, line 128
    def [](*args)
      hsh = new
      if Hash === args[0]
        hsh.replace(args[0])
      elsif (args.size % 2) != 0
        raise ArgumentError, "odd number of elements for Hash"
      else
        while !args.empty?
          hsh[args.shift] = args.shift
        end
      end
      hsh
    end

Alternate to new which creates a dictionary sorted by key.

  d = Dictionary.alpha
  d["z"] = 1
  d["y"] = 2
  d["x"] = 3
  d  #=> {"x"=>3,"y"=>2,"z"=>2}

This is equivalent to:

  Dictionary.new.order_by { |key,value| key }

[Source]

# File lib/more/facets/dictionary.rb, line 160
    def alpha(*args, &block)
      new(*args, &block).order_by_key
    end

Alternate to new which auto-creates sub-dictionaries as needed.

  d = Dictionary.auto
  d["a"]["b"]["c"] = "abc"  #=> { "a"=>{"b"=>{"c"=>"abc"}}}

[Source]

# File lib/more/facets/dictionary.rb, line 169
    def auto(*args)
      #AutoDictionary.new(*args)
      leet = lambda { |hsh, key| hsh[key] = new(&leet) }
      new(*args, &leet)
    end

New Dictiionary.

[Source]

# File lib/more/facets/dictionary.rb, line 178
  def initialize(*args, &blk)
    @order = []
    @order_by = nil
    if blk
      dict = self                                  # This ensure autmatic key entry effect the
      oblk = lambda{ |hsh, key| blk[dict,key] }    # dictionary rather then just the interal hash.
      @hash = Hash.new(*args, &oblk)
    else
      @hash = Hash.new(*args)
    end
  end

Like new but the block sets the order.

[Source]

# File lib/more/facets/dictionary.rb, line 144
    def new_by(*args, &blk)
      new(*args).order_by(&blk)
    end

Public Instance methods

[Source]

# File lib/more/facets/dictionary.rb, line 375
  def <<(kv)
    push(*kv)
  end

def ==( hsh2 )

  return false if @order != hsh2.order
  super hsh2

end

[Source]

# File lib/more/facets/dictionary.rb, line 256
  def ==(hsh2)
    if hsh2.is_a?( Dictionary )
      @order == hsh2.order &&
      @hash  == hsh2.instance_variable_get("@hash")
    else
      false
    end
  end

[Source]

# File lib/more/facets/dictionary.rb, line 265
  def [] k
    @hash[ k ]
  end

Store operator.

  h[key] = value

Or with additional index.

 h[key,index] = value

[Source]

# File lib/more/facets/dictionary.rb, line 281
  def []=(k, i=nil, v=nil)
    if v
      insert(i,k,v)
    else
      store(k,i)
    end
  end

[Source]

# File lib/more/facets/dictionary.rb, line 299
  def clear
    @order = []
    @hash.clear
  end

[Source]

# File lib/more/facets/dictionary.rb, line 304
  def delete( key )
    @order.delete( key )
    @hash.delete( key )
  end

[Source]

# File lib/more/facets/dictionary.rb, line 325
  def delete_if
    order.clone.each { |k| delete k if yield(k,@hash[k]) }
    self
  end

[Source]

# File lib/more/facets/dictionary.rb, line 400
  def dup
    a = []
    each{ |k,v| a << k; a << v }
    self.class[*a]
  end

[Source]

# File lib/more/facets/dictionary.rb, line 319
  def each
    order.each { |k| yield( k,@hash[k] ) }
    self
  end

[Source]

# File lib/more/facets/dictionary.rb, line 309
  def each_key
    order.each { |k| yield( k ) }
    self
  end
each_pair()

Alias for each

[Source]

# File lib/more/facets/dictionary.rb, line 314
  def each_value
    order.each { |k| yield( @hash[k] ) }
    self
  end

[Source]

# File lib/more/facets/dictionary.rb, line 449
  def empty?
    @hash.empty?
  end

[Source]

# File lib/more/facets/dictionary.rb, line 269
  def fetch(k, *a, &b)
    @hash.fetch(k, *a, &b)
  end

[Source]

# File lib/more/facets/dictionary.rb, line 433
  def first(x=nil)
    return @hash[order.first] unless x
    order.first(x).collect { |k| @hash[k] }
  end

[Source]

# File lib/more/facets/dictionary.rb, line 453
  def has_key?(key)
    @hash.has_key?(key)
  end

[Source]

# File lib/more/facets/dictionary.rb, line 289
  def insert( i,k,v )
    @order.insert( i,k )
    @hash.store( k,v )
  end

[Source]

# File lib/more/facets/dictionary.rb, line 394
  def inspect
    ary = []
    each {|k,v| ary << k.inspect + "=>" + v.inspect}
    '{' + ary.join(", ") + '}'
  end

[Source]

# File lib/more/facets/dictionary.rb, line 340
  def invert
    hsh2 = self.class.new
    order.each { |k| hsh2[@hash[k]] = k }
    hsh2
  end

[Source]

# File lib/more/facets/dictionary.rb, line 457
  def key?(key)
    @hash.key?(key)
  end

[Source]

# File lib/more/facets/dictionary.rb, line 336
  def keys
    order
  end

[Source]

# File lib/more/facets/dictionary.rb, line 439
  def last(x=nil)
    return @hash[order.last] unless x
    order.last(x).collect { |k| @hash[k] }
  end

[Source]

# File lib/more/facets/dictionary.rb, line 444
  def length
    @order.length
  end

[Source]

# File lib/more/facets/dictionary.rb, line 413
  def merge( hsh2 )
    self.dup.update(hsh2)
  end
merge!( hsh2 )

Alias for update

[Source]

# File lib/more/facets/dictionary.rb, line 190
  def order
    reorder if @order_by
    @order
  end

Keep dictionary sorted by a specific sort order.

[Source]

# File lib/more/facets/dictionary.rb, line 197
  def order_by( &block )
    @order_by = block
    order
    self
  end

Keep dictionary sorted by key.

  d = Dictionary.new.order_by_key
  d["z"] = 1
  d["y"] = 2
  d["x"] = 3
  d  #=> {"x"=>3,"y"=>2,"z"=>2}

This is equivalent to:

  Dictionary.new.order_by { |key,value| key }

The initializer Dictionary#alpha also provides this.

[Source]

# File lib/more/facets/dictionary.rb, line 217
  def order_by_key
    @order_by = lambda { |k,v| k }
    order
    self
  end

Keep dictionary sorted by value.

  d = Dictionary.new.order_by_value
  d["z"] = 1
  d["y"] = 2
  d["x"] = 3
  d  #=> {"x"=>3,"y"=>2,"z"=>2}

This is equivalent to:

  Dictionary.new.order_by { |key,value| value }

[Source]

# File lib/more/facets/dictionary.rb, line 235
  def order_by_value
    @order_by = lambda { |k,v| v }
    order
    self
  end

[Source]

# File lib/more/facets/dictionary.rb, line 389
  def pop
    key = order.last
    key ? [key,delete(key)] : nil
  end

[Source]

# File lib/more/facets/dictionary.rb, line 379
  def push( k,v )
    unless @hash.include?( k )
      @order.push( k )
      @hash.store( k,v )
      true
    else
      false
    end
  end

[Source]

# File lib/more/facets/dictionary.rb, line 346
  def reject(&block)
    self.dup.delete_if(&block)
  end

[Source]

# File lib/more/facets/dictionary.rb, line 350
  def reject!( &block )
    hsh2 = reject(&block)
    self == hsh2 ? nil : hsh2
  end

[Source]

# File lib/more/facets/dictionary.rb, line 243
  def reorder
    if @order_by
      assoc = @order.collect{ |k| [k,@hash[k]] }.sort_by(&@order_by)
      @order = assoc.collect{ |k,v| k }
    end
    @order
  end

[Source]

# File lib/more/facets/dictionary.rb, line 355
  def replace( hsh2 )
    @order = hsh2.order
    @hash = hsh2.hash
  end

[Source]

# File lib/more/facets/dictionary.rb, line 428
  def reverse
    dup.reverse!
  end

[Source]

# File lib/more/facets/dictionary.rb, line 423
  def reverse!
    @order.reverse!
    self
  end

[Source]

# File lib/more/facets/dictionary.rb, line 417
  def select
    ary = []
    each { |k,v| ary << [k,v] if yield k,v }
    ary
  end

[Source]

# File lib/more/facets/dictionary.rb, line 360
  def shift
    key = order.first
    key ? [key,delete(key)] : super
  end
size()

Alias for length

[Source]

# File lib/more/facets/dictionary.rb, line 294
  def store( a,b )
    @order.push( a ) unless @hash.has_key?( a )
    @hash.store( a,b )
  end

[Source]

# File lib/more/facets/dictionary.rb, line 461
  def to_a
    ary = []
    each { |k,v| ary << [k,v] }
    ary
  end

[Source]

# File lib/more/facets/dictionary.rb, line 475
  def to_h
    @hash.dup
  end

[Source]

# File lib/more/facets/dictionary.rb, line 471
  def to_hash
    @hash.dup
  end

[Source]

# File lib/more/facets/dictionary.rb, line 467
  def to_s
    self.to_a.to_s
  end

[Source]

# File lib/more/facets/dictionary.rb, line 365
  def unshift( k,v )
    unless @hash.include?( k )
      @order.unshift( k )
      @hash.store( k,v )
      true
    else
      false
    end
  end

[Source]

# File lib/more/facets/dictionary.rb, line 406
  def update( hsh2 )
    hsh2.each { |k,v| self[k] = v }
    reorder
    self
  end

[Source]

# File lib/more/facets/dictionary.rb, line 330
  def values
    ary = []
    order.each { |k| ary.push @hash[k] }
    ary
  end

[Validate]