class Array
# Standard in Ruby 1.9. See official documentation[http://ruby-doc.org/core-1.9/classes/Array.html]
class << self
# Try to convert obj into an array, using to_ary method.
# Returns converted array or nil if obj cannot be converted
# for any reason. This method is to check if an argument is an array.
def try_convert(obj)
return nil unless obj.respond_to?(:to_ary)
Type.coerce_to(obj, Array, :to_ary)
end
end
# Standard in Ruby 1.8.7+. See official documentation[http://ruby-doc.org/core-1.9/classes/Array.html]
def combination(num)
num = Type.coerce_to num, Fixnum, :to_int
return to_enum(:combination, num) unless block_given?
return self unless (0..size).include? num
# Implementation note: slightly tricky.
# Example: self = 1..7, num = 3
picks = (0...num).to_a # picks start at 0, 1, 2
max = ((size-num)...size).to_a # max (index for a given pick) is [4, 5, 6]
pick_max_pairs = picks.zip(max).reverse # pick_max_pairs = [[2, 6], [1, 5], [0, 4]]
lookup = pick_max_pairs.find(Proc.new{return self})
loop do
yield values_at(*picks)
move = lookup.each{|pick, max| picks[pick] < max}.first
new_index = picks[move] + 1
picks[move...num] = (new_index...(new_index+num-move)).to_a
end
end unless method_defined? :combination
# Standard in Ruby 1.8.7+. See official documentation[http://ruby-doc.org/core-1.9/classes/Array.html]
def cycle(n = nil, &block)
return to_enum(:cycle, n) unless block_given?
if n.nil?
loop(&block)
else
n = Type.coerce_to n, Fixnum, :to_int
n.times{each(&block)}
end
nil
end unless method_defined? :cycle
# Standard in rails, and we use it here...
def extract_options!
last.is_a?(::Hash) ? pop : {}
end unless method_defined? :extract_options!
# Standard in Ruby 1.8.7+. See official documentation[http://ruby-doc.org/core-1.9/classes/Array.html]
make_block_optional :collect!, :map!, :each, :each_index, :reverse_each, :reject, :reject!, :delete_if, :test_on => [42]
# flatten & flatten!, standard in ruby 1.8.7+. See official documentation[http://ruby-doc.org/core-1.9/classes/Array.html]
unless ([[]].flatten(1) rescue false)
# Recursively flatten any contained Arrays into an one-dimensional result.
# Adapted from rubinius'
def flatten_with_optional_argument(level=-1)
dup.flatten!(level) || self
end
# Flattens self in place as #flatten. If no changes are
# made, returns nil, otherwise self.
# Adapted from rubinius'
def flatten_with_optional_argument!(level=-1)
level = Type.coerce_to(level, Integer, :to_int)
return flatten_without_optional_argument! unless level >= 0
ret, out = nil, []
ret = recursively_flatten_finite(self, out, level)
replace(out) if ret
ret
end
alias_method_chain :flatten, :optional_argument
alias_method_chain :flatten!, :optional_argument
# Helper to recurse through flattening
# Adapted from rubinius'; recursion guards are not needed because level is finite
def recursively_flatten_finite(array, out, level)
ret = nil
if level <= 0
out.concat(array)
else
array.each do |o|
if o.respond_to? :to_ary
recursively_flatten_finite(o.to_ary, out, level - 1)
ret = self
else
out << o
end
end
end
ret
end
private :recursively_flatten_finite
end # flatten & flatten!
# index. Standard in Ruby 1.8.7+. See official documentation[http://ruby-doc.org/core-1.9/classes/Array.html]
unless ([1].index{true} rescue false)
def index_with_block(*arg)
return index_without_block(*arg) unless block_given? && arg.empty?
each_with_index{|o,i| return i if yield o}
return nil
end
alias_method_chain :index, :block
alias_method :find_index, :index
end
# pop. Standard in Ruby 1.8.7+. See official documentation[http://ruby-doc.org/core-1.9/classes/Array.html]
unless ([1].pop(1) rescue false)
def pop_with_optional_argument(n = Undefined)
return pop_without_optional_argument if n == Undefined
n = Type.coerce_to(n, Fixnum, :to_int)
raise ArgumentError, "negative array size" if n < 0
first = size - n
first = 0 if first < 0
slice!(first..size).to_a
end
alias_method_chain :pop, :optional_argument
end
# Standard in Ruby 1.9. See official documentation[http://ruby-doc.org/core-1.9/classes/Array.html]
def product(*arg)
# Implementation notes: We build an enumerator for all the combinations
# by building it up successively using "inject" and starting from a trivial enumerator.
# It would be easy to have "product" yield to a block but the standard
# simply returns an array, so you'll find a simple call to "to_a" at the end.
#
trivial_enum = Enumerator.new{|yielder| yielder.yield [] }
[self, *arg].map{|x| Type.coerce_to(x, Array, :to_ary)}.
inject(trivial_enum) do |enum, array|
Enumerator.new do |yielder|
enum.each do |partial_product|
array.each do |obj|
yielder.yield partial_product + [obj]
end
end
end
end.to_a
end unless method_defined? :product
# rindex
unless ([1].rindex{true} rescue false)
def rindex_with_block(*arg)
return rindex_without_block(*arg) unless block_given? && arg.empty?
reverse_each.each_with_index{|o,i| return size - 1 - i if yield o}
return nil
end
alias_method_chain :rindex, :block
end
# Standard in Ruby 1.8.7+. See official documentation[http://ruby-doc.org/core-1.9/classes/Array.html]
def sample(n = Undefined)
return self[rand(size)] if n == Undefined
n = Type.coerce_to(n, Fixnum, :to_int)
raise ArgumentError, "negative array size" if n < 0
n = size if n > size
result = Array.new(self)
n.times do |i|
r = i + rand(size - i)
result[i], result[r] = result[r], result[i]
end
result[n..size] = []
result
end unless method_defined? :sample
# shift. Standard in Ruby 1.8.7+. See official documentation[http://ruby-doc.org/core-1.9/classes/Array.html]
unless ([1].shift(1) rescue false)
def shift_with_optional_argument(n = Undefined)
return shift_without_optional_argument if n == Undefined
n = Type.coerce_to(n, Fixnum, :to_int)
raise ArgumentError, "negative array size" if n < 0
slice!(0, n)
end
alias_method_chain :shift, :optional_argument
end
# Standard in Ruby 1.8.7+. See official documentation[http://ruby-doc.org/core-1.9/classes/Array.html]
def shuffle
dup.shuffle!
end unless method_defined? :shuffle
# Standard in Ruby 1.8.7+. See official documentation[http://ruby-doc.org/core-1.9/classes/Array.html]
def shuffle!
size.times do |i|
r = i + rand(size - i)
self[i], self[r] = self[r], self[i]
end
self
end unless method_defined? :shuffle!
end