Module: Enumerable

Included in:
Symbol
Defined in:
lib/backports/enumerable.rb

Constant Summary collapse

MOST_EXTREME_OBJECT_EVER =

:nodoc:

Object.new

Instance Method Summary collapse

Instance Method Details

#count(*arg) ⇒ Object

Standard in ruby 1.9. See official documentation



13
14
15
16
17
18
19
20
21
22
23
24
 
# File 'lib/backports/enumerable.rb', line 13

def count(*arg)
  result = 0
  if block_given?
    each{|o| result += 1 if yield o}
  elsif arg.empty?
    each{|o| result += 1}
  else
    obj = arg.first
    each{|o| result += 1 if obj == o}
  end
  result
end

#cycle(*arg, &block) ⇒ Object

Standard in ruby 1.9. See official documentation



27
28
29
30
 
# File 'lib/backports/enumerable.rb', line 27

def cycle(*arg, &block)
  return to_enum(:cycle, *arg) unless block_given?
  to_a.cycle(*arg, &block)
end

#drop(n) ⇒ Object

Standard in ruby 1.9. See official documentation



35
36
37
38
 
# File 'lib/backports/enumerable.rb', line 35

def drop(n)
  array = to_a
  array[n...array.size] || []
end

#drop_while(&block) ⇒ Object

Standard in ruby 1.9. See official documentation



41
42
43
44
45
46
47
48
 
# File 'lib/backports/enumerable.rb', line 41

def drop_while(&block)
  return to_enum(:drop_while) unless block_given?
  array = to_a
  array.each_with_index do |element, i|
    return array.drop(i) unless yield(element)
  end
  []
end

#each_with_index_with_optional_args_and_block(*args, &block) ⇒ Object 



55
56
57
58
 
# File 'lib/backports/enumerable.rb', line 55

def each_with_index_with_optional_args_and_block(*args, &block)
  return to_enum(:each_with_index, *args) unless block_given?
  to_enum(:each, *args).each_with_index_without_optional_args_and_block(&block)
end

#each_with_object(memo, &block) ⇒ Object

Standard in ruby 1.9. See official documentation



63
64
65
66
67
 
# File 'lib/backports/enumerable.rb', line 63

def each_with_object(memo, &block)
  return to_enum(:each_with_object, memo) unless block_given?
  each {|obj| block.call(obj, memo)}
  memo
end

#find_index(*args) ⇒ Object

Standard in ruby 1.9. See official documentation

Raises:

  • (ArgumentError) 


70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
 
# File 'lib/backports/enumerable.rb', line 70

def find_index(*args)
  raise ArgumentError, "Wrong number of arguments (#{args.size} for 1)" if args.size > 1
  if args.size == 1
    obj = args.first
    each_with_index do |element, i|
      return i if element == obj
    end
  elsif block_given?
    each_with_index do |element, i|
      return i if yield element
    end
    each_with_index{|o,i| return i if yield o}
  else
    return to_enum(:find_index)
  end
  nil
end

#first(*arg) ⇒ Object

Standard in ruby 1.9. See official documentation



89
90
91
 
# File 'lib/backports/enumerable.rb', line 89

def first(*arg)
  arg.empty? ? take(1)[0] : take(arg.first)
end

#group_by ⇒ Object

Standard in ruby 1.9. See official documentation



94
95
96
97
98
99
100
101
 
# File 'lib/backports/enumerable.rb', line 94

def group_by
  return to_enum(:group_by) unless block_given?
  returning({}) do |result|
    each do |o|
      result.fetch(yield(o)){|key| result[key] = []} << o
    end
  end
end

#inject_with_symbol(*args, &block) ⇒ Object

Raises:

  • (TypeError) 


105
106
107
108
109
110
111
 
# File 'lib/backports/enumerable.rb', line 105

def inject_with_symbol(*args, &block)
  return inject_without_symbol(*args, &block) if block_given?
  method = args.pop
  raise TypeError, "#{method} is not a symbol" unless method.respond_to? :to_sym
  method = method.to_sym
  inject_without_symbol(*args) {|memo, obj| memo.send(method, obj)}
end

#max_by(&block) ⇒ Object

Standard in ruby 1.9. See official documentation



127
128
129
130
 
# File 'lib/backports/enumerable.rb', line 127

def max_by(&block)
  return to_enum(:max_by) unless block_given?
  minmax_by(&block)[1]
end

#min_by(&block) ⇒ Object

Standard in ruby 1.9. See official documentation



133
134
135
136
 
# File 'lib/backports/enumerable.rb', line 133

def min_by(&block)
  return to_enum(:min_by) unless block_given?
  minmax_by(&block).first
end

#minmax ⇒ Object

Standard in ruby 1.9. See official documentation



139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
 
# File 'lib/backports/enumerable.rb', line 139

def minmax
  return minmax{|a,b| a <=> b} unless block_given?
  first_time = true
  min, max = nil
  each do |object|
    if first_time
      min = max = object
      first_time = false
    else
      min = object if yield(min, object) > 0
      max = object if yield(max, object) < 0
    end
  end
  [min, max]
end

#minmax_by(&block) ⇒ Object

Standard in ruby 1.9. See official documentation



156
157
158
159
160
161
162
163
164
165
166
 
# File 'lib/backports/enumerable.rb', line 156

def minmax_by(&block)
  return to_enum(:minmax_by) unless block_given?
  min_object, min_result = nil, MOST_EXTREME_OBJECT_EVER
  max_object, max_result = nil, MOST_EXTREME_OBJECT_EVER
  each do |object|
    result = yield object
    min_object, min_result = object, result if min_result > result
    max_object, max_result = object, result if max_result < result
  end
  [min_object, max_object]
end

#none?(&block) ⇒ Boolean

Standard in ruby 1.9. See official documentation

Returns:

  • (Boolean) 


169
170
171
 
# File 'lib/backports/enumerable.rb', line 169

def none?(&block)
  !any?(&block)
end

#one?(&block) ⇒ Boolean

Standard in ruby 1.9. See official documentation

Returns:

  • (Boolean) 


174
175
176
177
 
# File 'lib/backports/enumerable.rb', line 174

def one?(&block)
  return one?{|o| o} unless block_given?
  1 == count(&block)
end

#reverse_each(&block) ⇒ Object

Standard in ruby 1.9. See official documentation



182
183
184
185
186
187
 
# File 'lib/backports/enumerable.rb', line 182

def reverse_each(&block)
  return to_enum(:reverse_each) unless block_given?
  # There is no other way then to convert to an array first... see 1.9's source.
  to_a.reverse_each(&block)
  self
end

#sum(identity = 0, &block) ⇒ Object

Standard in rails… See official documentation Modified from rails 2.3 to not rely on size



4
5
6
7
8
9
10
 
# File 'lib/backports/enumerable.rb', line 4

def sum(identity = 0, &block)
  if block_given?
    map(&block).sum(identity)
  else
    inject { |sum, element| sum + element } || identity
  end
end

#take(n) ⇒ Object

Standard in ruby 1.9. See official documentation



190
191
192
193
194
195
196
197
 
# File 'lib/backports/enumerable.rb', line 190

def take(n)
  returning([]) do |array|
    each do |elem|
      array << elem
      break if array.size >= n
    end unless n <= 0
  end
end

#take_while ⇒ Object

Standard in ruby 1.9. See official documentation



200
201
202
203
204
205
206
 
# File 'lib/backports/enumerable.rb', line 200

def take_while
  return to_enum(:take_while) unless block_given?
  inject([]) do |array, elem|
    return array unless yield elem
    array << elem
  end
end

#to_a_with_optional_arguments(*args) ⇒ Object 



210
211
212
213
 
# File 'lib/backports/enumerable.rb', line 210

def to_a_with_optional_arguments(*args)
  return to_a_without_optional_arguments if args.empty?
  to_enum(:each, *args).to_a
end