ruby/array.rb

158 строки
4.6 KiB
Ruby

class Array
# call-seq:
# array.shuffle!(random: Random) -> array
#
# Shuffles the elements of +self+ in place.
# a = [1, 2, 3] #=> [1, 2, 3]
# a.shuffle! #=> [2, 3, 1]
# a #=> [2, 3, 1]
#
# The optional +random+ argument will be used as the random number generator:
# a.shuffle!(random: Random.new(1)) #=> [1, 3, 2]
def shuffle!(random: Random)
Primitive.rb_ary_shuffle_bang(random)
end
# call-seq:
# array.shuffle(random: Random) -> new_ary
#
# Returns a new array with elements of +self+ shuffled.
# a = [1, 2, 3] #=> [1, 2, 3]
# a.shuffle #=> [2, 3, 1]
# a #=> [1, 2, 3]
#
# The optional +random+ argument will be used as the random number generator:
# a.shuffle(random: Random.new(1)) #=> [1, 3, 2]
def shuffle(random: Random)
Primitive.rb_ary_shuffle(random)
end
# call-seq:
# array.sample(random: Random) -> object
# array.sample(n, random: Random) -> new_ary
#
# Returns random elements from +self+.
#
# When no arguments are given, returns a random element from +self+:
# a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
# a.sample # => 3
# a.sample # => 8
# If +self+ is empty, returns +nil+.
#
# When argument +n+ is given, returns a new \Array containing +n+ random
# elements from +self+:
# a.sample(3) # => [8, 9, 2]
# a.sample(6) # => [9, 6, 10, 3, 1, 4]
# Returns no more than <tt>a.size</tt> elements
# (because no new duplicates are introduced):
# a.sample(a.size * 2) # => [6, 4, 1, 8, 5, 9, 10, 2, 3, 7]
# But +self+ may contain duplicates:
# a = [1, 1, 1, 2, 2, 3]
# a.sample(a.size * 2) # => [1, 1, 3, 2, 1, 2]
# The argument +n+ must be a non-negative numeric value.
# The order of the result array is unrelated to the order of +self+.
# Returns a new empty \Array if +self+ is empty.
#
# The optional +random+ argument will be used as the random number generator:
# a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
# a.sample(random: Random.new(1)) #=> 6
# a.sample(4, random: Random.new(1)) #=> [6, 10, 9, 2]
def sample(n = (ary = false), random: Random)
if Primitive.mandatory_only?
# Primitive.cexpr! %{ rb_ary_sample(self, rb_cRandom, Qfalse, Qfalse) }
Primitive.ary_sample0
else
# Primitive.cexpr! %{ rb_ary_sample(self, random, n, ary) }
Primitive.ary_sample(random, n, ary)
end
end
# call-seq:
# array.first -> object or nil
# array.first(n) -> new_array
#
# Returns elements from +self+; does not modify +self+.
#
# When no argument is given, returns the first element:
#
# a = [:foo, 'bar', 2]
# a.first # => :foo
# a # => [:foo, "bar", 2]
#
# If +self+ is empty, returns +nil+.
#
# When non-negative Integer argument +n+ is given,
# returns the first +n+ elements in a new \Array:
#
# a = [:foo, 'bar', 2]
# a.first(2) # => [:foo, "bar"]
#
# If <tt>n >= array.size</tt>, returns all elements:
#
# a = [:foo, 'bar', 2]
# a.first(50) # => [:foo, "bar", 2]
#
# If <tt>n == 0</tt> returns an new empty \Array:
#
# a = [:foo, 'bar', 2]
# a.first(0) # []
#
# Related: #last.
def first n = unspecified = true
if Primitive.mandatory_only?
Primitive.attr! :leaf
Primitive.cexpr! %q{ ary_first(self) }
else
if unspecified
Primitive.cexpr! %q{ ary_first(self) }
else
Primitive.cexpr! %q{ ary_take_first_or_last_n(self, NUM2LONG(n), ARY_TAKE_FIRST) }
end
end
end
# call-seq:
# array.last -> object or nil
# array.last(n) -> new_array
#
# Returns elements from +self+; +self+ is not modified.
#
# When no argument is given, returns the last element:
#
# a = [:foo, 'bar', 2]
# a.last # => 2
# a # => [:foo, "bar", 2]
#
# If +self+ is empty, returns +nil+.
#
# When non-negative Integer argument +n+ is given,
# returns the last +n+ elements in a new \Array:
#
# a = [:foo, 'bar', 2]
# a.last(2) # => ["bar", 2]
#
# If <tt>n >= array.size</tt>, returns all elements:
#
# a = [:foo, 'bar', 2]
# a.last(50) # => [:foo, "bar", 2]
#
# If <tt>n == 0</tt>, returns an new empty \Array:
#
# a = [:foo, 'bar', 2]
# a.last(0) # []
#
# Related: #first.
def last n = unspecified = true
if Primitive.mandatory_only?
Primitive.attr! :leaf
Primitive.cexpr! %q{ ary_last(self) }
else
if unspecified
Primitive.cexpr! %q{ ary_last(self) }
else
Primitive.cexpr! %q{ ary_take_first_or_last_n(self, NUM2LONG(n), ARY_TAKE_LAST) }
end
end
end
end