Class: Dictionary

### Home Classes Methods

### In Files

- lib/extlib/dictionary.rb

### Parent

Object

### Methods

- ::[]
- ::alpha
- ::auto
- ::new
- ::new_by
- #<<
- #==
- #[]
- #[]=
- #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!
- #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_json
- #to_s
- #unshift
- #update
- #values

### Included Modules

- Enumerable

### Files

- LICENSE
- README.rdoc

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# 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 doesn'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.

### Public Class Methods

[](*args) click to toggle source

    # File lib/extlib/dictionary.rb, line 88
    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

alpha(*args, &block) click to toggle source

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 }

    # File lib/extlib/dictionary.rb, line 119
    def alpha(*args, &block)
      new(*args, &block).order_by_key
    end

auto(*args) click to toggle source

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

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

    # File lib/extlib/dictionary.rb, line 128
    def auto(*args)
      #AutoDictionary.new(*args)
      leet = lambda { |hsh, key| hsh[key] = new(&leet) }
      new(*args, &leet)
    end

new(*args, &blk) click to toggle source

New Dictiionary.

    # File lib/extlib/dictionary.rb, line 136
    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

new_by(*args, &blk) click to toggle source

Like new but the block sets the order.

    # File lib/extlib/dictionary.rb, line 104
    def new_by(*args, &blk)
      new(*args).order_by(&blk)
    end

### Public Instance Methods

<<(kv) click to toggle source

    # File lib/extlib/dictionary.rb, line 323
    def <<(kv)
      push( *kv )
    end

==(hsh2) click to toggle source

    # File lib/extlib/dictionary.rb, line 205
    def ==(hsh2)
      if hsh2.is_a?( Dictionary )
        @order == hsh2.order &&
        @hash  == hsh2.instance_variable_get("@hash")
      else
        false
      end
    end

[](k) click to toggle source

    # File lib/extlib/dictionary.rb, line 214
    def [] k
      @hash[ k ]
    end

[]=(k, i=nil, v=nil) click to toggle source

Store operator.

    h[key] = value

Or with additional index.

    h[key,index] = value

    # File lib/extlib/dictionary.rb, line 229
    def []=(k, i=nil, v=nil)
      if v
        insert(i,k,v)
      else
        store(k,i)
      end
    end

clear() click to toggle source

    # File lib/extlib/dictionary.rb, line 247
    def clear
      @order = []
      @hash.clear
    end

delete( key ) click to toggle source

    # File lib/extlib/dictionary.rb, line 252
    def delete( key )
      @order.delete( key )
      @hash.delete( key )
    end

delete_if() click to toggle source

    # File lib/extlib/dictionary.rb, line 273
    def delete_if
      order.clone.each { |k| delete k if yield(k,@hash[k]) }
      self
    end

dup() click to toggle source

    # File lib/extlib/dictionary.rb, line 348
    def dup
      a = []
      each{ |k,v| a << k; a << v }
      self.class[*a]
    end

each() click to toggle source

    # File lib/extlib/dictionary.rb, line 267
    def each
      order.each { |k| yield( k,@hash[k] ) }
      self
    end

Also aliased as: each_pair
each_key() click to toggle source

    # File lib/extlib/dictionary.rb, line 257
    def each_key
      order.each { |k| yield( k ) }
      self
    end

each_pair() click to toggle source
Alias for: each
each_value() click to toggle source

    # File lib/extlib/dictionary.rb, line 262
    def each_value
      order.each { |k| yield( @hash[k] ) }
      self
    end

empty?() click to toggle source

    # File lib/extlib/dictionary.rb, line 393
    def empty?
      @hash.empty?
    end

fetch(k, *a, &b) click to toggle source

    # File lib/extlib/dictionary.rb, line 218
    def fetch(k, *a, &b)
      @hash.fetch(k, *a, &b)
    end

first() click to toggle source

    # File lib/extlib/dictionary.rb, line 380
    def first
      @hash[order.first]
    end

has_key?(key) click to toggle source

    # File lib/extlib/dictionary.rb, line 397
    def has_key?(key)
      @hash.has_key?(key)
    end

insert( i,k,v ) click to toggle source

    # File lib/extlib/dictionary.rb, line 237
    def insert( i,k,v )
      @order.insert( i,k )
      @hash.store( k,v )
    end

inspect() click to toggle source

    # File lib/extlib/dictionary.rb, line 342
    def inspect
      ary = []
      each {|k,v| ary << k.inspect + "=>" + v.inspect}
      '{' + ary.join(", ") + '}'
    end

invert() click to toggle source

    # File lib/extlib/dictionary.rb, line 288
    def invert
      hsh2 = self.class.new
      order.each { |k| hsh2[@hash[k]] = k }
      hsh2
    end

key?(key) click to toggle source

    # File lib/extlib/dictionary.rb, line 401
    def key?(key)
      @hash.key?(key)
    end

keys() click to toggle source

    # File lib/extlib/dictionary.rb, line 284
    def keys
      order
    end

last() click to toggle source

    # File lib/extlib/dictionary.rb, line 384
    def last
      @hash[order.last]
    end

length() click to toggle source

    # File lib/extlib/dictionary.rb, line 388
    def length
      @order.length
    end

Also aliased as: size
merge( hsh2 ) click to toggle source

    # File lib/extlib/dictionary.rb, line 361
    def merge( hsh2 )
      self.dup.update(hsh2)
    end

merge!( hsh2 ) click to toggle source
Alias for: update
order() click to toggle source

    # File lib/extlib/dictionary.rb, line 148
    def order
      reorder if @order_by
      @order
    end

order_by( &block ) click to toggle source

Keep dictionary sorted by a specific sort order.

    # File lib/extlib/dictionary.rb, line 154
    def order_by( &block )
      @order_by = block
      order
      self
    end

order_by_key() click to toggle source

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.

    # File lib/extlib/dictionary.rb, line 173
    def order_by_key
      @order_by = lambda { |k,v| k }
      order
      self
    end

order_by_value() click to toggle source

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 }

    # File lib/extlib/dictionary.rb, line 190
    def order_by_value
      @order_by = lambda { |k,v| v }
      order
      self
    end

pop() click to toggle source

    # File lib/extlib/dictionary.rb, line 337
    def pop
      key = order.last
      key ? [key,delete(key)] : nil
    end

push( k,v ) click to toggle source

    # File lib/extlib/dictionary.rb, line 327
    def push( k,v )
      unless @hash.include?( k )
        @order.push( k )
        @hash.store( k,v )
        true
      else
        false
      end
    end

reject( &block ) click to toggle source

    # File lib/extlib/dictionary.rb, line 294
    def reject( &block )
      self.dup.delete_if(&block)
    end

reject!( &block ) click to toggle source

    # File lib/extlib/dictionary.rb, line 298
    def reject!( &block )
      hsh2 = reject(&block)
      self == hsh2 ? nil : hsh2
    end

reorder() click to toggle source

    # File lib/extlib/dictionary.rb, line 197
    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

replace( hsh2 ) click to toggle source

    # File lib/extlib/dictionary.rb, line 303
    def replace( hsh2 )
      @order = hsh2.order
      @hash = hsh2.hash
    end

reverse() click to toggle source

    # File lib/extlib/dictionary.rb, line 376
    def reverse
      dup.reverse!
    end

reverse!() click to toggle source

    # File lib/extlib/dictionary.rb, line 371
    def reverse!
      @order.reverse!
      self
    end

select() click to toggle source

    # File lib/extlib/dictionary.rb, line 365
    def select
      ary = []
      each { |k,v| ary << [k,v] if yield k,v }
      ary
    end

shift() click to toggle source

    # File lib/extlib/dictionary.rb, line 308
    def shift
      key = order.first
      key ? [key,delete(key)] : super
    end

size() click to toggle source
Alias for: length
store( a,b ) click to toggle source

    # File lib/extlib/dictionary.rb, line 242
    def store( a,b )
      @order.push( a ) unless @hash.has_key?( a )
      @hash.store( a,b )
    end

to_a() click to toggle source

    # File lib/extlib/dictionary.rb, line 405
    def to_a
      ary = []
      each { |k,v| ary << [k,v] }
      ary
    end

to_h() click to toggle source

    # File lib/extlib/dictionary.rb, line 430
    def to_h
      @hash.dup
    end

to_hash() click to toggle source

    # File lib/extlib/dictionary.rb, line 426
    def to_hash
      @hash.dup
    end

to_json() click to toggle source

    # File lib/extlib/dictionary.rb, line 411
    def to_json
      buf = "["
      map do |k,v|
        buf << k.to_json
        buf << ", "
        buf << v.to_json
      end.join(", ")
      buf << "]"
      buf
    end

to_s() click to toggle source

    # File lib/extlib/dictionary.rb, line 422
    def to_s
      self.to_a.to_s
    end

unshift( k,v ) click to toggle source

    # File lib/extlib/dictionary.rb, line 313
    def unshift( k,v )
      unless @hash.include?( k )
        @order.unshift( k )
        @hash.store( k,v )
        true
      else
        false
      end
    end

update( hsh2 ) click to toggle source

    # File lib/extlib/dictionary.rb, line 354
    def update( hsh2 )
      hsh2.each { |k,v| self[k] = v }
      reorder
      self
    end

Also aliased as: merge!
values() click to toggle source

    # File lib/extlib/dictionary.rb, line 278
    def values
      ary = []
      order.each { |k| ary.push @hash[k] }
      ary
    end

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