Class: OrderedHash

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

Overview

OrderedHash

Version

1.2006.07.13 (change of the first number means Big Change)

Description

Hash which preserves order of added items (like PHP array).

Usage

(see examples directory under the ruby gems root directory)

require 'rubygems' require 'ordered_hash'

hsh = OrderedHash.new hsh = 1 hsh = 2 hsh = 3 p hsh.keys # ['z','a','c']

Source

http://simplypowerful.1984.cz/goodlibs/1.2006.07.13

Author

jan molic (/mig/at_sign/1984/dot/cz/)

Thanks to

Andrew Johnson for his suggestions and fixes of Hash, merge, to_a, inspect and shift Desmond Dsouza for == fixes

Licence

You can redistribute it and/or modify it under the same terms of Ruby's license; either the dual license version in 2003, or any later version.

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 57

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 39

def order
  @order
end

Class Method Details

.[](*args) ⇒ Object 



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# File 'lib/orderedhash.rb', line 43

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
		hsh[args.shift] = args.shift while args.size > 0
	end
	hsh
end

Instance Method Details

#==(hsh2) ⇒ Object 



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

def == hsh2
	return hsh2==self if !hsh2.is_a?(OrderedHash)
	return false if @order != hsh2.order
	super hsh2
end

#clear ⇒ Object 



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# File 'lib/orderedhash.rb', line 81

def clear
	@order = []
	super
end

#delete(key) ⇒ Object 



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

def delete key
	@order.delete key
	super
end

#delete_if ⇒ Object 



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# File 'lib/orderedhash.rb', line 108

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

#each ⇒ Object Also known as: each_pair 



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

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

#each_key ⇒ Object 



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# File 'lib/orderedhash.rb', line 91

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

#each_value ⇒ Object 



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# File 'lib/orderedhash.rb', line 96

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

#first ⇒ Object 



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# File 'lib/orderedhash.rb', line 175

def first
	self[@order.first]
end

#inspect ⇒ Object 



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# File 'lib/orderedhash.rb', line 193

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 125

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 121

def keys
	@order
end

#last ⇒ Object 



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# File 'lib/orderedhash.rb', line 179

def last
	self[@order.last]
end

#merge(hsh2) ⇒ Object 



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# File 'lib/orderedhash.rb', line 206

def merge hsh2
	self.dup update(hsh2)
end

#orig_store ⇒ Object 



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# File 'lib/orderedhash.rb', line 66

alias orig_store store

#pop ⇒ Object 



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# File 'lib/orderedhash.rb', line 170

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

#push(k, v) ⇒ Object 



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

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 131

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

#reject!(&block) ⇒ Object 



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# File 'lib/orderedhash.rb', line 135

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

#replace(hsh2) ⇒ Object 



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# File 'lib/orderedhash.rb', line 140

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

#select ⇒ Object 



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# File 'lib/orderedhash.rb', line 210

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 145

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 68

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 62

def store_only a,b
	store a,b
end

#to_a ⇒ Object 



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# File 'lib/orderedhash.rb', line 183

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

#to_s ⇒ Object 



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# File 'lib/orderedhash.rb', line 189

def to_s
	self.to_a.to_s
end

#unshift(k, v) ⇒ Object 



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# File 'lib/orderedhash.rb', line 150

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 199

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

#values ⇒ Object 



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# File 'lib/orderedhash.rb', line 115

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