Results for: "Data"

A recommended version for use with a ~> Requirement.

Calls the block with each repeated combination of length n of the elements of self; each combination is an Array; returns self. The order of the combinations is indeterminate.

When a block and a positive Integer argument n are given, calls the block with each n-tuple repeated combination of the elements of self. The number of combinations is (n+1)(n+2)/2.

n = 1:

a = [0, 1, 2]
a.repeated_combination(1) {|combination| p combination }

Output:

[0]
[1]
[2]

n = 2:

a.repeated_combination(2) {|combination| p combination }

Output:

[0, 0]
[0, 1]
[0, 2]
[1, 1]
[1, 2]
[2, 2]

If n is zero, calls the block once with an empty Array.

If n is negative, does not call the block:

a.repeated_combination(-1) {|combination| fail 'Cannot happen' }

Returns a new Enumerator if no block given:

a = [0, 1, 2]
a.repeated_combination(2) # => #<Enumerator: [0, 1, 2]:combination(2)>

Using Enumerators, it’s convenient to show the combinations and counts for some values of n:

e = a.repeated_combination(0)
e.size # => 1
e.to_a # => [[]]
e = a.repeated_combination(1)
e.size # => 3
e.to_a # => [[0], [1], [2]]
e = a.repeated_combination(2)
e.size # => 6
e.to_a # => [[0, 0], [0, 1], [0, 2], [1, 1], [1, 2], [2, 2]]

Makes a list of existing constants private.

Makes a list of existing constants deprecated. Attempt to refer to them will produce a warning.

module HTTP
  NotFound = Exception.new
  NOT_FOUND = NotFound # previous version of the library used this name

  deprecate_constant :NOT_FOUND
end

HTTP::NOT_FOUND
# warning: constant HTTP::NOT_FOUND is deprecated

Returns true if the arguments define a valid ordinal date, false otherwise:

Date.valid_date?(2001, 2, 3)  # => true
Date.valid_date?(2001, 2, 29) # => false
Date.valid_date?(2001, 2, -1) # => true

See argument start.

Related: Date.jd, Date.new.

Returns self.

Returns a DateTime whose value is the same as self:

Date.new(2001, 2, 3).to_datetime # => #<DateTime: 2001-02-03T00:00:00+00:00>

Returns a Date object which denotes self.

Returns self.

Returns a Date object which denotes self.

Returns a DateTime object which denotes self.

Returns true if this class can be used to create an instance from a serialised JSON string. The class has to implement a class method json_create that expects a hash as first parameter. The hash should include the required data.

Returns the object for which the receiver is the singleton class.

Raises an TypeError if the class is not a singleton class.

class Foo; end

Foo.singleton_class.attached_object        #=> Foo
Foo.attached_object                        #=> TypeError: `Foo' is not a singleton class
Foo.new.singleton_class.attached_object    #=> #<Foo:0x000000010491a370>
TrueClass.attached_object                  #=> TypeError: `TrueClass' is not a singleton class
NilClass.attached_object                   #=> TypeError: `NilClass' is not a singleton class

Returns garbage collector generation for the given object.

class B
  include ObjectSpace

  def foo
    trace_object_allocations do
      obj = Object.new
      p "Generation is #{allocation_generation(obj)}"
    end
  end
end

B.new.foo #=> "Generation is 3"

See ::trace_object_allocations for more information and examples.

Returns information for heaps in the GC.

If the first optional argument, heap_name, is passed in and not nil, it returns a Hash containing information about the particular heap. Otherwise, it will return a Hash with heap names as keys and a Hash containing information about the heap as values.

If the second optional argument, hash_or_key, is given as Hash, it will be overwritten and returned. This is intended to avoid the probe effect.

If both optional arguments are passed in and the second optional argument is a symbol, it will return a Numeric of the value for the particular heap.

On CRuby, heap_name is of the type Integer but may be of type String on other implementations.

The contents of the hash are implementation specific and may change in the future without notice.

If the optional argument, hash, is given, it is overwritten and returned.

This method is only expected to work on CRuby.

The hash includes the following keys about the internal information in the GC:

slot_size

The slot size of the heap in bytes.

heap_allocatable_pages

The number of pages that can be allocated without triggering a new garbage collection cycle.

heap_eden_pages

The number of pages in the eden heap.

heap_eden_slots

The total number of slots in all of the pages in the eden heap.

heap_tomb_pages

The number of pages in the tomb heap. The tomb heap only contains pages that do not have any live objects.

heap_tomb_slots

The total number of slots in all of the pages in the tomb heap.

total_allocated_pages

The total number of pages that have been allocated in the heap.

total_freed_pages

The total number of pages that have been freed and released back to the system in the heap.

force_major_gc_count

The number of times major garbage collection cycles this heap has forced to start due to running out of free slots.

force_incremental_marking_finish_count

The number of times this heap has forced incremental marking to complete due to running out of pooled slots.

The path to standard location of the user’s state file.

The path to standard location of the user’s state directory.

How String Gem paths should be split. Overridable for esoteric platforms.