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

Source

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.



57
58
59
60
 
# File 'lib/orderedhash.rb', line 57

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

Instance Attribute Details

#order ⇒ Object

Returns the value of attribute order.



39
40
41
 
# File 'lib/orderedhash.rb', line 39

def order
  @order
end

Class Method Details

.[](*args) ⇒ Object 



43
44
45
46
47
48
49
50
51
52
53
 
# 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 



75
76
77
78
79
 
# 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 



81
82
83
84
 
# File 'lib/orderedhash.rb', line 81

def clear
	@order = []
	super
end

#delete(key) ⇒ Object 



86
87
88
89
 
# File 'lib/orderedhash.rb', line 86

def delete key
	@order.delete key
	super
end

#delete_if ⇒ Object 



108
109
110
111
112
113
 
# 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 



101
102
103
104
 
# File 'lib/orderedhash.rb', line 101

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

#each_key ⇒ Object 



91
92
93
94
 
# File 'lib/orderedhash.rb', line 91

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

#each_value ⇒ Object 



96
97
98
99
 
# File 'lib/orderedhash.rb', line 96

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

#first ⇒ Object 



175
176
177
 
# File 'lib/orderedhash.rb', line 175

def first
	self[@order.first]
end

#inspect ⇒ Object 



193
194
195
196
197
 
# File 'lib/orderedhash.rb', line 193

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

#invert ⇒ Object 



125
126
127
128
129
 
# File 'lib/orderedhash.rb', line 125

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

#keys ⇒ Object 



121
122
123
 
# File 'lib/orderedhash.rb', line 121

def keys
	@order
end

#last ⇒ Object 



179
180
181
 
# File 'lib/orderedhash.rb', line 179

def last
	self[@order.last]
end

#merge(hsh2) ⇒ Object 



206
207
208
 
# File 'lib/orderedhash.rb', line 206

def merge hsh2
	self.dup update(hsh2)
end

#orig_store ⇒ Object 



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

alias orig_store store

#pop ⇒ Object 



170
171
172
173
 
# File 'lib/orderedhash.rb', line 170

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

#push(k, v) ⇒ Object 



160
161
162
163
164
165
166
167
168
 
# 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 



131
132
133
 
# File 'lib/orderedhash.rb', line 131

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

#reject!(&block) ⇒ Object 



135
136
137
138
 
# File 'lib/orderedhash.rb', line 135

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

#replace(hsh2) ⇒ Object 



140
141
142
143
 
# File 'lib/orderedhash.rb', line 140

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

#select ⇒ Object 



210
211
212
213
214
 
# File 'lib/orderedhash.rb', line 210

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

#shift ⇒ Object 



145
146
147
148
 
# File 'lib/orderedhash.rb', line 145

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

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



68
69
70
71
 
# 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 



62
63
64
 
# File 'lib/orderedhash.rb', line 62

def store_only a,b
	store a,b
end

#to_a ⇒ Object 



183
184
185
186
187
 
# File 'lib/orderedhash.rb', line 183

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

#to_s ⇒ Object 



189
190
191
 
# File 'lib/orderedhash.rb', line 189

def to_s
	self.to_a.to_s
end

#unshift(k, v) ⇒ Object 



150
151
152
153
154
155
156
157
158
 
# 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! 



199
200
201
202
 
# File 'lib/orderedhash.rb', line 199

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

#values ⇒ Object 



115
116
117
118
119
 
# File 'lib/orderedhash.rb', line 115

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