ruby/hash.rb

41 строка
1.6 KiB
Ruby

class Hash
# call-seq:
# Hash.new(default_value = nil) -> new_hash
# Hash.new(default_value = nil, capacity: size) -> new_hash
# Hash.new {|hash, key| ... } -> new_hash
# Hash.new(capacity: size) {|hash, key| ... } -> new_hash
#
# Returns a new empty +Hash+ object.
#
# The initial default value and initial default proc for the new hash
# depend on which form above was used. See {Default Values}[rdoc-ref:Hash@Default+Values].
#
# If neither an argument nor a block is given,
# initializes both the default value and the default proc to <tt>nil</tt>:
# h = Hash.new
# h.default # => nil
# h.default_proc # => nil
#
# If argument <tt>default_value</tt> is given but no block is given,
# initializes the default value to the given <tt>default_value</tt>
# and the default proc to <tt>nil</tt>:
# h = Hash.new(false)
# h.default # => false
# h.default_proc # => nil
#
# If a block is given but no <tt>default_value</tt>, stores the block as the default proc
# and sets the default value to <tt>nil</tt>:
# h = Hash.new {|hash, key| "Default value for #{key}" }
# h.default # => nil
# h.default_proc.class # => Proc
# h[:nosuch] # => "Default value for nosuch"
#
# If both a block and a <tt>default_value</tt> are given, raises an +ArgumentError+
#
# If the optional keyword argument +capacity+ is given, the hash will be allocated
# with enough capacity to accomodate this many keys without having to be resized.
def initialize(ifnone = (ifnone_unset = true), capacity: 0, &block)
Primitive.rb_hash_init(capacity, ifnone_unset, ifnone, block)
end
end