Returns a new Array that is a recursive flattening of self:
Each non-Array element is unchanged.
Each Array is replaced by its individual elements.
With non-negative Integer argument level, flattens recursively through level levels:
a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten(0) # => [0, [1, [2, 3], 4], 5] a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten(1) # => [0, 1, [2, 3], 4, 5] a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten(2) # => [0, 1, 2, 3, 4, 5] a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten(3) # => [0, 1, 2, 3, 4, 5]
With no argument, a nil argument, or with negative argument level, flattens all levels:
a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten # => [0, 1, 2, 3, 4, 5] [0, 1, 2].flatten # => [0, 1, 2] a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten(-1) # => [0, 1, 2, 3, 4, 5] a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten(-2) # => [0, 1, 2, 3, 4, 5] [0, 1, 2].flatten(-1) # => [0, 1, 2]
Replaces each nested Array in self with the elements from that Array; returns self if any changes, nil otherwise.
With non-negative Integer argument level, flattens recursively through level levels:
a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten!(1) # => [0, 1, [2, 3], 4, 5] a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten!(2) # => [0, 1, 2, 3, 4, 5] a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten!(3) # => [0, 1, 2, 3, 4, 5] [0, 1, 2].flatten!(1) # => nil
With no argument, a nil argument, or with negative argument level, flattens all levels:
a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten! # => [0, 1, 2, 3, 4, 5] [0, 1, 2].flatten! # => nil a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten!(-1) # => [0, 1, 2, 3, 4, 5] a = [ 0, [ 1, [2, 3], 4 ], 5 ] a.flatten!(-2) # => [0, 1, 2, 3, 4, 5] [0, 1, 2].flatten!(-1) # => nil
Calls the block, if given, with combinations of elements of self; returns self. The order of combinations is indeterminate.
When a block and an in-range positive Integer argument n (0 < n <= self.size) are given, calls the block with all n-tuple combinations of self.
Example:
a = [0, 1, 2] a.combination(2) {|combination| p combination }
Output:
[0, 1] [0, 2] [1, 2]
Another example:
a = [0, 1, 2] a.combination(3) {|combination| p combination }
Output:
[0, 1, 2]
When n is zero, calls the block once with a new empty Array:
a = [0, 1, 2] a1 = a.combination(0) {|combination| p combination }
Output:
[]
When n is out of range (negative or larger than self.size), does not call the block:
a = [0, 1, 2] a.combination(-1) {|combination| fail 'Cannot happen' } a.combination(4) {|combination| fail 'Cannot happen' }
Returns a new Enumerator if no block given:
a = [0, 1, 2] a.combination(2) # => #<Enumerator: [0, 1, 2]:combination(2)>
Returns a new Array containing the first n element of self, where n is a non-negative Integer; does not modify self.
Examples:
a = [0, 1, 2, 3, 4, 5] a.take(1) # => [0] a.take(2) # => [0, 1] a.take(50) # => [0, 1, 2, 3, 4, 5] a # => [0, 1, 2, 3, 4, 5]
The primary interface to this library. Use to setup delegation when defining your class.
class MyClass < DelegateClass(ClassToDelegateTo) # Step 1 def initialize super(obj_of_ClassToDelegateTo) # Step 2 end end
or:
MyClass = DelegateClass(ClassToDelegateTo) do # Step 1 def initialize super(obj_of_ClassToDelegateTo) # Step 2 end end
Here’s a sample of use from Tempfile which is really a File object with a few special rules about storage location and when the File should be deleted. That makes for an almost textbook perfect example of how to use delegation.
class Tempfile < DelegateClass(File) # constant and class member data initialization... def initialize(basename, tmpdir=Dir::tmpdir) # build up file path/name in var tmpname... @tmpfile = File.open(tmpname, File::RDWR|File::CREAT|File::EXCL, 0600) # ... super(@tmpfile) # below this point, all methods of File are supported... end # ... end
Returns object. This method is deprecated and will be removed in Ruby 3.2.
Returns false. This method is deprecated and will be removed in Ruby 3.2.
Returns object. This method is deprecated and will be removed in Ruby 3.2.
Returns self truncated (toward zero) to a precision of ndigits decimal digits.
When ndigits is negative, the returned value has at least ndigits.abs trailing zeros:
555.truncate(-1) # => 550 555.truncate(-2) # => 500 -555.truncate(-2) # => -500
Returns self when ndigits is zero or positive.
555.truncate # => 555 555.truncate(50) # => 555
Related: Integer#round.
Returns self.
Returns 1.
Returns the value as a rational. The optional argument eps is always ignored.
Returns a complex object which denotes the given rectangular form.
Complex.rectangular(1, 2) #=> (1+2i)
Returns the numerator.
1 2 3+4i <- numerator
- + -i -> ----
2 3 6 <- denominator
c = Complex('1/2+2/3i') #=> ((1/2)+(2/3)*i)
n = c.numerator #=> (3+4i)
d = c.denominator #=> 6
n / d #=> ((1/2)+(2/3)*i)
Complex(Rational(n.real, d), Rational(n.imag, d))
#=> ((1/2)+(2/3)*i)
See denominator.
Returns the denominator (lcm of both denominator - real and imag).
See numerator.
Returns the value as a rational if possible (the imaginary part should be exactly zero).
Complex(1.0/3, 0).rationalize #=> (1/3) Complex(1, 0.0).rationalize # RangeError Complex(1, 2).rationalize # RangeError
See to_r.
Returns zero as a rational. The optional argument eps is always ignored.
Returns an array; [num, 0].
Returns self.
Returns self truncated (toward zero) to a precision of digits decimal digits.
Numeric implements this by converting self to a Float and invoking Float#truncate.
Returns true if self is less than 0, false otherwise.
Returns the numerator.
Returns the denominator (always positive).