ruby/integer.rb

126 строки
3.0 KiB
Ruby

class Integer
def abs
Primitive.attr! 'inline'
Primitive.cexpr! 'rb_int_abs(self)'
end
# call-seq:
# int.bit_length -> integer
#
# Returns the number of bits of the value of +int+.
#
# "Number of bits" means the bit position of the highest bit
# which is different from the sign bit
# (where the least significant bit has bit position 1).
# If there is no such bit (zero or minus one), zero is returned.
#
# I.e. this method returns <i>ceil(log2(int < 0 ? -int : int+1))</i>.
#
# (-2**1000-1).bit_length #=> 1001
# (-2**1000).bit_length #=> 1000
# (-2**1000+1).bit_length #=> 1000
# (-2**12-1).bit_length #=> 13
# (-2**12).bit_length #=> 12
# (-2**12+1).bit_length #=> 12
# -0x101.bit_length #=> 9
# -0x100.bit_length #=> 8
# -0xff.bit_length #=> 8
# -2.bit_length #=> 1
# -1.bit_length #=> 0
# 0.bit_length #=> 0
# 1.bit_length #=> 1
# 0xff.bit_length #=> 8
# 0x100.bit_length #=> 9
# (2**12-1).bit_length #=> 12
# (2**12).bit_length #=> 13
# (2**12+1).bit_length #=> 13
# (2**1000-1).bit_length #=> 1000
# (2**1000).bit_length #=> 1001
# (2**1000+1).bit_length #=> 1001
#
# This method can be used to detect overflow in Array#pack as follows:
#
# if n.bit_length < 32
# [n].pack("l") # no overflow
# else
# raise "overflow"
# end
def bit_length
Primitive.attr! 'inline'
Primitive.cexpr! 'rb_int_bit_length(self)'
end
# call-seq:
# int.even? -> true or false
#
# Returns +true+ if +int+ is an even number.
def even?
Primitive.attr! 'inline'
Primitive.cexpr! 'rb_int_even_p(self)'
end
# call-seq:
# int.integer? -> true
#
# Since +int+ is already an Integer, this always returns +true+.
def integer?
return true
end
def magnitude
Primitive.attr! 'inline'
Primitive.cexpr! 'rb_int_abs(self)'
end
# call-seq:
# int.odd? -> true or false
#
# Returns +true+ if +int+ is an odd number.
def odd?
Primitive.attr! 'inline'
Primitive.cexpr! 'rb_int_odd_p(self)'
end
# call-seq:
# int.ord -> self
#
# Returns the +int+ itself.
#
# 97.ord #=> 97
#
# This method is intended for compatibility to character literals
# in Ruby 1.9.
#
# For example, <code>?a.ord</code> returns 97 both in 1.8 and 1.9.
def ord
return self
end
# call-seq:
# int.to_i -> integer
#
# Since +int+ is already an Integer, returns +self+.
#
# #to_int is an alias for #to_i.
def to_i
return self
end
# call-seq:
# int.to_int -> integer
#
# Since +int+ is already an Integer, returns +self+.
def to_int
return self
end
# call-seq:
# int.zero? -> true or false
#
# Returns +true+ if +int+ has a zero value.
def zero?
Primitive.attr! 'inline'
Primitive.cexpr! 'rb_int_zero_p(self)'
end
end