Calls the given block with each integer value from self
down to limit
; returns self
:
a = [] 10.downto(5) {|i| a << i } # => 10 a # => [10, 9, 8, 7, 6, 5] a = [] 0.downto(-5) {|i| a << i } # => 0 a # => [0, -1, -2, -3, -4, -5] 4.downto(5) {|i| fail 'Cannot happen' } # => 4
With no block given, returns an Enumerator
.
Returns self
.
Returns 1
.
Returns the Complex object created from the numerators of the real and imaginary parts of self
, after converting each part to the lowest common denominator of the two:
c = Complex.rect(Rational(2, 3), Rational(3, 4)) # => ((2/3)+(3/4)*i) c.numerator # => (8+9i)
In this example, the lowest common denominator of the two parts is 12; the two converted parts may be thought of as Rational(8, 12) and Rational(9, 12), whose numerators, respectively, are 8 and 9; so the returned value of c.numerator
is Complex.rect(8, 9)
.
Related: Complex#denominator
.
Returns the denominator of self
, which is the least common multiple of self.real.denominator
and self.imag.denominator
:
Complex.rect(Rational(1, 2), Rational(2, 3)).denominator # => 6
Note that n.denominator
of a non-rational numeric is 1
.
Related: Complex#numerator
.
Returns the numerator.
Returns the denominator (always positive).
With a block given, calls the block with each String
value returned by successive calls to String#succ
; the first value is self
, the next is self.succ
, and so on; the sequence terminates when value other_string
is reached; returns self
:
'a8'.upto('b6') {|s| print s, ' ' } # => "a8"
Output:
a8 a9 b0 b1 b2 b3 b4 b5 b6
If argument exclusive
is given as a truthy object, the last value is omitted:
'a8'.upto('b6', true) {|s| print s, ' ' } # => "a8"
Output:
a8 a9 b0 b1 b2 b3 b4 b5
If other_string
would not be reached, does not call the block:
'25'.upto('5') {|s| fail s } 'aa'.upto('a') {|s| fail s }
With no block given, returns a new Enumerator:
'a8'.upto('b6') # => #<Enumerator: "a8":upto("b6")>
Returns the numerator. The result is machine dependent.
n = 0.3.numerator #=> 5404319552844595 d = 0.3.denominator #=> 18014398509481984 n.fdiv(d) #=> 0.3
See also Float#denominator
.
Returns the denominator (always positive). The result is machine dependent.
See also Float#numerator
.
Returns a copy of the storage hash for the fiber. The method can only be called on the Fiber.current
.
Sets the storage hash for the fiber. This feature is experimental and may change in the future. The method can only be called on the Fiber.current
.
You should be careful about using this method as you may inadvertently clear important fiber-storage state. You should mostly prefer to assign specific keys in the storage using Fiber::[]=
.
You can also use Fiber.new(storage: nil)
to create a fiber with an empty storage.
Example:
while request = request_queue.pop # Reset the per-request state: Fiber.current.storage = nil handle_request(request) end
With string object
given, returns true
if path
is a string path leading to a directory, or to a symbolic link to a directory; false
otherwise:
File.directory?('.') # => true File.directory?('foo') # => false File.symlink('.', 'dirlink') # => 0 File.directory?('dirlink') # => true File.symlink('t,txt', 'filelink') # => 0 File.directory?('filelink') # => false
Argument path
can be an IO
object.
Registers filename to be loaded (using Kernel::require) the first time that const (which may be a String
or a symbol) is accessed in the namespace of mod.
module A end A.autoload(:B, "b") A::B.doit # autoloads "b"
If const in mod is defined as autoload, the file name to be loaded is replaced with filename. If const is defined but not as autoload, does nothing.
Files that are currently being loaded must not be registered for autoload.
Returns filename to be loaded if name is registered as autoload
in the namespace of mod or one of its ancestors.
module A end A.autoload(:B, "b") A.autoload?(:B) #=> "b"
If inherit
is false, the lookup only checks the autoloads in the receiver:
class A autoload :CONST, "const.rb" end class B < A end B.autoload?(:CONST) #=> "const.rb", found in A (ancestor) B.autoload?(:CONST, false) #=> nil, not found in B itself
Returns a list of modules included/prepended in mod (including mod itself).
module Mod include Math include Comparable prepend Enumerable end Mod.ancestors #=> [Enumerable, Mod, Comparable, Math] Math.ancestors #=> [Math] Enumerable.ancestors #=> [Enumerable]
Returns a new Date object constructed from the present date:
Date.today.to_s # => "2022-07-06"
See argument start.
Equivalent to step
with arguments min
and -1
.
Returns the offset in seconds between the timezones of UTC and self
:
Time.utc(2000, 1, 1).utc_offset # => 0 Time.local(2000, 1, 1).utc_offset # => -21600 # -6*3600, or minus six hours.
Set
the cursor position at line
and column
.
You must require ‘io/console’ to use this method.
Returns the numerator.
Rational(7).numerator #=> 7 Rational(7, 1).numerator #=> 7 Rational(9, -4).numerator #=> -9 Rational(-2, -10).numerator #=> 1
Returns the denominator (always positive).
Rational(7).denominator #=> 1 Rational(7, 1).denominator #=> 1 Rational(9, -4).denominator #=> 4 Rational(-2, -10).denominator #=> 5
Tokenizes the Ruby
program and returns an array of strings. The filename
and lineno
arguments are mostly ignored, since the return value is just the tokenized input. By default, this method does not handle syntax errors in src
, use the raise_errors
keyword to raise a SyntaxError
for an error in src
.
p Ripper.tokenize("def m(a) nil end") # => ["def", " ", "m", "(", "a", ")", " ", "nil", " ", "end"]