Is code
an informational status?
Set
the real user ID of the calling process to user. Not available on all platforms.
Set
the real group ID of the calling process to group. Not available on all platforms.
Sets the (user) real and/or effective user IDs of the current process to rid and eid, respectively. A value of -1
for either means to leave that ID unchanged. Not available on all platforms.
Sets the (group) real and/or effective group IDs of the current process to rid and eid, respectively. A value of -1
for either means to leave that ID unchanged. Not available on all platforms.
Sets the (user) real, effective, and saved user IDs of the current process to rid, eid, and sid respectively. A value of -1
for any value means to leave that ID unchanged. Not available on all platforms.
Sets the (group) real, effective, and saved user IDs of the current process to rid, eid, and sid respectively. A value of -1
for any value means to leave that ID unchanged. Not available on all platforms.
Returns whether this dependency, which has no possible matching specifications, can safely be ignored.
@param [Object] dependency @return [Boolean] whether this dependency can safely be skipped.
Load extra data embed into binary format String
object.
Reset nil attributes to their default values to make the spec valid
Tries to convert obj
into an array, using the to_ary
method. Returns the converted array or nil
if obj
cannot be converted. This method can be used to check if an argument is an array.
Array.try_convert([1]) #=> [1] Array.try_convert("1") #=> nil if tmp = Array.try_convert(arg) # the argument is an array elsif tmp = String.try_convert(arg) # the argument is a string end
Replaces the contents of self
with the contents of other_ary
, truncating or expanding if necessary.
a = [ "a", "b", "c", "d", "e" ] a.replace([ "x", "y", "z" ]) #=> ["x", "y", "z"] a #=> ["x", "y", "z"]
Same as Array#each
, but passes the index
of the element instead of the element itself.
An Enumerator
is returned if no block is given.
a = [ "a", "b", "c" ] a.each_index {|x| print x, " -- " }
produces:
0 -- 1 -- 2 --
When invoked with a block, yields all repeated combinations of length n
of elements from the array and then returns the array itself.
The implementation makes no guarantees about the order in which the repeated combinations are yielded.
If no block is given, an Enumerator
is returned instead.
Examples:
a = [1, 2, 3] a.repeated_combination(1).to_a #=> [[1], [2], [3]] a.repeated_combination(2).to_a #=> [[1,1],[1,2],[1,3],[2,2],[2,3],[3,3]] a.repeated_combination(3).to_a #=> [[1,1,1],[1,1,2],[1,1,3],[1,2,2],[1,2,3], # [1,3,3],[2,2,2],[2,2,3],[2,3,3],[3,3,3]] a.repeated_combination(4).to_a #=> [[1,1,1,1],[1,1,1,2],[1,1,1,3],[1,1,2,2],[1,1,2,3], # [1,1,3,3],[1,2,2,2],[1,2,2,3],[1,2,3,3],[1,3,3,3], # [2,2,2,2],[2,2,2,3],[2,2,3,3],[2,3,3,3],[3,3,3,3]] a.repeated_combination(0).to_a #=> [[]] # one combination of length 0
By using binary search, finds an index of a value from this array which meets the given condition in O(log n) where n is the size of the array.
It supports two modes, depending on the nature of the block. They are exactly the same as in the case of the bsearch
method, with the only difference being that this method returns the index of the element instead of the element itself. For more details consult the documentation for bsearch
.
Returns the list of private methods accessible to obj. If the all parameter is set to false
, only those methods in the receiver will be listed.
Returns true
if class is the class of obj, or if class is one of the superclasses of obj or modules included in obj.
module M; end class A include M end class B < A; end class C < B; end b = B.new b.is_a? A #=> true b.is_a? B #=> true b.is_a? C #=> false b.is_a? M #=> true b.kind_of? A #=> true b.kind_of? B #=> true b.kind_of? C #=> false b.kind_of? M #=> true
Returns the factorization of self
.
See Prime#prime_division
for more details.
Iterates the given block over all prime numbers.
See Prime
#each for more details.
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 ceil(log2(int < 0 ? -int : int+1)).
(-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