Class: OrderedHash

Inherits:
Hash
  • Object
show all
Defined in:
lib/orderedhash.rb

Overview

AUTHOR

jan molic /mig/at/1984/dot/cz/

DESCRIPTION

Hash with preserved order and some array-like extensions
Public domain.

THANKS

Andrew Johnson for his suggestions and fixes of Hash[],
merge, to_a, inspect and shift

Direct Known Subclasses

AutoOrderedHash

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*a, &b) ⇒ OrderedHash

Returns a new instance of OrderedHash.



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# File 'lib/orderedhash.rb', line 31

def initialize(*a, &b)
  super
  @order = []
end

Instance Attribute Details

#order ⇒ Object

Returns the value of attribute order.



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# File 'lib/orderedhash.rb', line 13

def order
  @order
end

#to_yaml_style ⇒ Object

Returns the value of attribute to_yaml_style.



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# File 'lib/orderedhash.rb', line 164

def to_yaml_style
  @to_yaml_style
end

Class Method Details

.[](*args) ⇒ Object 



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# File 'lib/orderedhash.rb', line 16

def [] *args
  hsh = OrderedHash.new
  if Hash === args[0]
    hsh.replace args[0]
  elsif (args.size % 2) != 0
    raise ArgumentError, "odd number of elements for Hash"
  else
    0.step(args.size - 1, 2) do |a|
      b = a + 1
      hsh[args[a]] = args[b]
    end
  end
  hsh
end

Instance Method Details

#==(hsh2) ⇒ Object 



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# File 'lib/orderedhash.rb', line 44

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

#__class__ ⇒ Object 



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# File 'lib/orderedhash.rb', line 160

def __class__
  OrderedHash
end

#class ⇒ Object 



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# File 'lib/orderedhash.rb', line 157

def class
  Hash
end

#clear ⇒ Object 



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# File 'lib/orderedhash.rb', line 48

def clear
    @order = []
    super
end

#delete(key) ⇒ Object 



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# File 'lib/orderedhash.rb', line 52

def delete key
    @order.delete key
    super
end

#delete_if ⇒ Object 



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# File 'lib/orderedhash.rb', line 69

def delete_if
    @order.clone.each { |k| 
        delete k if yield(k)
    }
    self
end

#each ⇒ Object Also known as: each_pair 



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# File 'lib/orderedhash.rb', line 64

def each
    @order.each { |k| yield k,self[k] }
    self
end

#each_key ⇒ Object 



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# File 'lib/orderedhash.rb', line 56

def each_key
    @order.each { |k| yield k }
    self
end

#each_value ⇒ Object 



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# File 'lib/orderedhash.rb', line 60

def each_value
    @order.each { |k| yield self[k] }
    self
end

#each_with_index ⇒ Object 



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# File 'lib/orderedhash.rb', line 192

def each_with_index
  @order.each_with_index { |k, index| yield k, self[k], index }
  self
end

#first ⇒ Object 



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# File 'lib/orderedhash.rb', line 83

def first
  {@order.first => self[@order.first]}
end

#inspect ⇒ Object 



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# File 'lib/orderedhash.rb', line 139

def inspect
    ary = []
    each {|k,v| ary << k.inspect + "=>" + v.inspect}
    '{' + ary.join(", ") + '}'
end

#invert ⇒ Object 



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# File 'lib/orderedhash.rb', line 89

def invert
    hsh2 = Hash.new    
    @order.each { |k| hsh2[self[k]] = k }
    hsh2
end

#keys ⇒ Object 



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# File 'lib/orderedhash.rb', line 80

def keys
    @order
end

#last ⇒ Object 



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# File 'lib/orderedhash.rb', line 86

def last
  {@order.last => self[@order.last]}
end

#merge(hsh2) ⇒ Object 



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# File 'lib/orderedhash.rb', line 149

def merge hsh2
    self.dup update(hsh2)
end

#orig_store ⇒ Object 



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# File 'lib/orderedhash.rb', line 38

alias orig_store store

#pop ⇒ Object 



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# File 'lib/orderedhash.rb', line 127

def pop
    key = @order.last
    key ? [key,delete(key)] : nil
end

#push(k, v) ⇒ Object 



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# File 'lib/orderedhash.rb', line 118

def push k,v
    unless self.include? k
        @order.push k
        orig_store(k,v)
        true
    else
        false
    end
end

#reject(&block) ⇒ Object 



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# File 'lib/orderedhash.rb', line 94

def reject &block
    self.dup.delete_if &block
end

#reject!(&block) ⇒ Object 



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# File 'lib/orderedhash.rb', line 97

def reject! &block
    hsh2 = reject &block
    self == hsh2 ? nil : hsh2
end

#replace(hsh2) ⇒ Object 



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# File 'lib/orderedhash.rb', line 101

def replace hsh2
    @order = hsh2.keys 
    super hsh2
end

#select ⇒ Object 



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# File 'lib/orderedhash.rb', line 152

def select
    ary = []
    each { |k,v| ary << [k,v] if yield k,v }
    ary
end

#shift ⇒ Object 



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# File 'lib/orderedhash.rb', line 105

def shift
    key = @order.first
    key ? [key,delete(key)] : super
end

#store(a, b) ⇒ Object Also known as: []= 



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# File 'lib/orderedhash.rb', line 39

def store a,b
    @order.push a unless has_key? a
    super a,b
end

#store_only(a, b) ⇒ Object 



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# File 'lib/orderedhash.rb', line 35

def store_only a,b
    store a,b
end

#to_a ⇒ Object 



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# File 'lib/orderedhash.rb', line 131

def to_a
    ary = []
    each { |k,v| ary << [k,v] }
    ary
end

#to_s ⇒ Object 



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# File 'lib/orderedhash.rb', line 136

def to_s
    self.to_a.to_s
end

#unshift(k, v) ⇒ Object 



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# File 'lib/orderedhash.rb', line 109

def unshift k,v
    unless self.include? k
        @order.unshift k
        orig_store(k,v)
        true
    else
        false
    end
end

#update(hsh2) ⇒ Object Also known as: merge! 



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# File 'lib/orderedhash.rb', line 144

def update hsh2
    hsh2.each { |k,v| self[k] = v }
    self
end

#values ⇒ Object 



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# File 'lib/orderedhash.rb', line 75

def values
    ary = []
    @order.each { |k| ary.push self[k] }
    ary
end

#yaml_inline! ⇒ Object 



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# File 'lib/orderedhash.rb', line 190

def yaml_inline!() self.yaml_inline = true end

#yaml_inline=(bool) ⇒ Object 



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# File 'lib/orderedhash.rb', line 165

def yaml_inline= bool
  if respond_to?("to_yaml_style")
    self.to_yaml_style = :inline
  else
    unless defined? @__yaml_inline_meth
      @__yaml_inline_meth =
        lambda {|opts|
          YAML::quick_emit(object_id, opts) {|emitter|
            emitter << '{ ' << map{|kv| kv.join ': '}.join(', ') << ' }'
          }
        }
      class << self
        def to_yaml opts = {}
          begin
            @__yaml_inline ? @__yaml_inline_meth[ opts ] : super
          rescue
            @to_yaml_style = :inline
            super
          end
        end
      end
    end
  end
  @__yaml_inline = bool
end