ruby/array.rb

262 строки
7.7 KiB
Ruby

class Array
# call-seq:
# each {|element| ... } -> self
# each -> new_enumerator
#
# With a block given, iterates over the elements of +self+,
# passing each element to the block;
# returns +self+:
#
# a = [:foo, 'bar', 2]
# a.each {|element| puts "#{element.class} #{element}" }
#
# Output:
#
# Symbol foo
# String bar
# Integer 2
#
# Allows the array to be modified during iteration:
#
# a = [:foo, 'bar', 2]
# a.each {|element| puts element; a.clear if element.to_s.start_with?('b') }
#
# Output:
#
# foo
# bar
#
# With no block given, returns a new Enumerator.
#
# Related: see {Methods for Iterating}[rdoc-ref:Array@Methods+for+Iterating].
def each
Primitive.attr! :inline_block
unless defined?(yield)
return Primitive.cexpr! 'SIZED_ENUMERATOR(self, 0, 0, ary_enum_length)'
end
_i = 0
value = nil
while Primitive.cexpr!(%q{ ary_fetch_next(self, LOCAL_PTR(_i), LOCAL_PTR(value)) })
yield value
end
self
end
# call-seq:
# shuffle!(random: Random) -> self
#
# Shuffles all elements in +self+ into a random order,
# as selected by the object given by keyword argument +random+;
# returns +self+:
#
# a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
# a.shuffle! # => [5, 3, 8, 7, 6, 1, 9, 4, 2, 0]
# a.shuffle! # => [9, 4, 0, 6, 2, 8, 1, 5, 3, 7]
#
# Duplicate elements are included:
#
# a = [0, 1, 0, 1, 0, 1, 0, 1, 0, 1]
# a.shuffle! # => [1, 0, 0, 1, 1, 0, 1, 0, 0, 1]
# a.shuffle! # => [0, 1, 0, 1, 1, 0, 1, 0, 1, 0]
#
# The object given with keyword argument +random+ is used as the random number generator.
#
# Related: see {Methods for Assigning}[rdoc-ref:Array@Methods+for+Assigning].
def shuffle!(random: Random)
Primitive.rb_ary_shuffle_bang(random)
end
# call-seq:
# shuffle(random: Random) -> new_array
#
# Returns a new array containing all elements from +self+ in a random order,
# as selected by the object given by keyword argument +random+:
#
# a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
# a.shuffle # => [0, 8, 1, 9, 6, 3, 4, 7, 2, 5]
# a.shuffle # => [8, 9, 0, 5, 1, 2, 6, 4, 7, 3]
#
# Duplicate elements are included:
#
# a = [0, 1, 0, 1, 0, 1, 0, 1, 0, 1]
# a.shuffle # => [1, 0, 1, 1, 0, 0, 1, 0, 0, 1]
# a.shuffle # => [1, 1, 0, 0, 0, 1, 1, 0, 0, 1]
#
# The object given with keyword argument +random+ is used as the random number generator.
#
# Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
def shuffle(random: Random)
Primitive.rb_ary_shuffle(random)
end
# call-seq:
# sample(random: Random) -> object
# sample(count, random: Random) -> new_ary
#
# Returns random elements from +self+,
# as selected by the object given by keyword argument +random+.
#
# With no argument +count+ given, returns one random element from +self+:
#
# a = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
# a.sample # => 3
# a.sample # => 8
#
# Returns +nil+ if +self+ is empty:
#
# [].sample # => nil
#
#
# With non-negative numeric argument +count+ given,
# returns a new array containing +count+ random elements from +self+:
#
# a.sample(3) # => [8, 9, 2]
# a.sample(6) # => [9, 6, 0, 3, 1, 4]
#
# The order of the result array is unrelated to the order of +self+.
#
# Returns a new empty +Array+ if +self+ is empty:
#
# [].sample(4) # => []
#
# May return duplicates in +self+:
#
# a = [1, 1, 1, 2, 2, 3]
# a.sample(a.size) # => [1, 1, 3, 2, 1, 2]
#
# Returns no more than <tt>a.size</tt> elements
# (because no new duplicates are introduced):
#
# a.sample(50) # => [6, 4, 1, 8, 5, 9, 0, 2, 3, 7]
#
# The object given with keyword argument +random+ is 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]
#
# Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
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:
# first -> object or nil
# first(count) -> new_array
#
# Returns elements from +self+, or +nil+; does not modify +self+.
#
# With no argument given, returns the first element (if available):
#
# a = [:foo, 'bar', 2]
# a.first # => :foo
# a # => [:foo, "bar", 2]
#
# If +self+ is empty, returns +nil+.
#
# [].first # => nil
#
# With non-negative integer argument +count+ given,
# returns the first +count+ elements (as available) in a new array:
#
# a.first(0) # => []
# a.first(2) # => [:foo, "bar"]
# a.first(50) # => [:foo, "bar", 2]
#
# Related: see {Methods for Querying}[rdoc-ref:Array@Methods+for+Querying].
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:
# last -> last_object or nil
# last(n) -> new_array
#
# Returns elements from +self+, or +nil+; +self+ is not modified.
#
# With no argument given, returns the last element, or +nil+ if +self+ is empty:
#
# a = [:foo, 'bar', 2]
# a.last # => 2
# a # => [:foo, "bar", 2]
# [].last # => nil
#
#
# With non-negative integer argument +n+ is given,
# returns a new array containing the trailing +n+ elements of +self+, as available:
#
# a = [:foo, 'bar', 2]
# a.last(2) # => ["bar", 2]
# a.last(50) # => [:foo, "bar", 2]
# a.last(0) # => []
# [].last(3) # => []
#
# Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
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
# call-seq:
# fetch_values(*indexes) -> new_array
# fetch_values(*indexes) {|index| ... } -> new_array
#
# With no block given, returns a new array containing the elements of +self+
# at the offsets given by +indexes+;
# each of the +indexes+ must be an
# {integer-convertible object}[rdoc-ref:implicit_conversion.rdoc@Integer-Convertible+Objects]:
#
# a = [:foo, :bar, :baz]
# a.fetch_values(3, 1) # => [:baz, :foo]
# a.fetch_values(3.1, 1) # => [:baz, :foo]
# a.fetch_values # => []
#
# For a negative index, counts backwards from the end of the array:
#
# a.fetch_values([-2, -1]) # [:bar, :baz]
#
# When no block is given, raises an exception if any index is out of range.
#
# With a block given, for each index:
#
# - If the index in in range, uses an element of +self+ (as above).
# - Otherwise calls, the block with the index, and uses the block's return value.
#
# Example:
#
# a = [:foo, :bar, :baz]
# a.fetch_values(1, 0, 42, 777) {|index| index.to_s}
# # => [:bar, :foo, "42", "777"]
#
# Related: see {Methods for Fetching}[rdoc-ref:Array@Methods+for+Fetching].
def fetch_values(*indexes, &block)
indexes.map! { |i| fetch(i, &block) }
indexes
end
end