Returns the Fiber scheduler, that was last set for the current thread with Fiber.set_scheduler. Returns nil if no scheduler is set (which is the default), and non-blocking fibers’ behavior is the same as blocking. (see “Non-blocking fibers” section in class docs for details about the scheduler concept).
The method is expected to immediately run the provided block of code in a separate non-blocking fiber.
puts "Go to sleep!" Fiber.set_scheduler(MyScheduler.new) Fiber.schedule do puts "Going to sleep" sleep(1) puts "I slept well" end puts "Wakey-wakey, sleepyhead"
Assuming MyScheduler is properly implemented, this program will produce:
Go to sleep! Going to sleep Wakey-wakey, sleepyhead ...1 sec pause here... I slept well
…e.g. on the first blocking operation inside the Fiber (sleep(1)), the control is yielded to the outside code (main fiber), and at the end of that execution, the scheduler takes care of properly resuming all the blocked fibers.
Note that the behavior described above is how the method is expected to behave, actual behavior is up to the current scheduler’s implementation of Fiber::Scheduler#fiber method. Ruby doesn’t enforce this method to behave in any particular way.
If the scheduler is not set, the method raises RuntimeError (No scheduler is available!).
Returns the fractional part of the day in range (Rational(0, 1)…Rational(1, 1)):
DateTime.new(2001,2,3,12).day_fraction # => (1/2)
Returns the fractional part of the second in range (Rational(0, 1)…Rational(1, 1)):
DateTime.new(2001, 2, 3, 4, 5, 6.5).sec_fraction # => (1/2)
Returns the sharing detection flag as a boolean value. It is false (nil) by default.
Sets the sharing detection flag to b.
Returns a new array that is the union of the elements of self and all given arrays other_arrays; items are compared using eql?:
[0, 1, 2, 3].union([4, 5], [6, 7]) # => [0, 1, 2, 3, 4, 5, 6, 7]
Removes duplicates (preserving the first found):
[0, 1, 1].union([2, 1], [3, 1]) # => [0, 1, 2, 3]
Preserves order (preserving the position of the first found):
[3, 2, 1, 0].union([5, 3], [4, 2]) # => [3, 2, 1, 0, 5, 4]
With no arguments given, returns a copy of self.
Related: see Methods for Combining.
Iterates over permutations of the elements of self; the order of permutations is indeterminate.
With a block and an in-range positive integer argument count (0 < count <= self.size) given, calls the block with each permutation of self of size count; returns self:
a = [0, 1, 2] perms = [] a.permutation(1) {|perm| perms.push(perm) } perms # => [[0], [1], [2]] perms = [] a.permutation(2) {|perm| perms.push(perm) } perms # => [[0, 1], [0, 2], [1, 0], [1, 2], [2, 0], [2, 1]] perms = [] a.permutation(3) {|perm| perms.push(perm) } perms # => [[0, 1, 2], [0, 2, 1], [1, 0, 2], [1, 2, 0], [2, 0, 1], [2, 1, 0]]
When count is zero, calls the block once with a new empty array:
perms = [] a.permutation(0) {|perm| perms.push(perm) } perms # => [[]]
When count is out of range (negative or larger than self.size), does not call the block:
a.permutation(-1) {|permutation| fail 'Cannot happen' } a.permutation(4) {|permutation| fail 'Cannot happen' }
With no block given, returns a new Enumerator.
Related: Methods for Iterating.
When a block and a positive integer-convertible object argument count (0 < count <= self.size) are given, calls the block with each combination of self of size count; returns self:
a = %w[a b c] # => ["a", "b", "c"] a.combination(2) {|combination| p combination } # => ["a", "b", "c"]
Output:
["a", "b"] ["a", "c"] ["b", "c"]
The order of the yielded combinations is not guaranteed.
When count is zero, calls the block once with a new empty array:
a.combination(0) {|combination| p combination } [].combination(0) {|combination| p combination }
Output:
[] []
When count is negative or larger than self.size and self is non-empty, does not call the block:
a.combination(-1) {|combination| fail 'Cannot happen' } # => ["a", "b", "c"] a.combination(4) {|combination| fail 'Cannot happen' } # => ["a", "b", "c"]
With no block given, returns a new Enumerator.
Related: Array#permutation; see also Methods for Iterating.
Returns the value as a rational. The optional argument eps is always ignored.
Returns a Rational object whose value is exactly or approximately equivalent to that of self.real.
With no argument epsilon given, returns a Rational object whose value is exactly equal to that of self.real.rationalize:
Complex.rect(1, 0).rationalize # => (1/1) Complex.rect(1, Rational(0, 1)).rationalize # => (1/1) Complex.rect(3.14159, 0).rationalize # => (314159/100000)
With argument epsilon given, returns a Rational object whose value is exactly or approximately equal to that of self.real to the given precision:
Complex.rect(3.14159, 0).rationalize(0.1) # => (16/5) Complex.rect(3.14159, 0).rationalize(0.01) # => (22/7) Complex.rect(3.14159, 0).rationalize(0.001) # => (201/64) Complex.rect(3.14159, 0).rationalize(0.0001) # => (333/106) Complex.rect(3.14159, 0).rationalize(0.00001) # => (355/113) Complex.rect(3.14159, 0).rationalize(0.000001) # => (7433/2366) Complex.rect(3.14159, 0).rationalize(0.0000001) # => (9208/2931) Complex.rect(3.14159, 0).rationalize(0.00000001) # => (47460/15107) Complex.rect(3.14159, 0).rationalize(0.000000001) # => (76149/24239) Complex.rect(3.14159, 0).rationalize(0.0000000001) # => (314159/100000) Complex.rect(3.14159, 0).rationalize(0.0) # => (3537115888337719/1125899906842624)
Related: Complex#to_r.
Returns zero as a Rational:
nil.rationalize # => (0/1)
Argument eps is ignored.
Returns a simpler approximation of the value (flt-|eps| <= result <= flt+|eps|). If the optional argument eps is not given, it will be chosen automatically.
0.3.rationalize #=> (3/10) 1.333.rationalize #=> (1333/1000) 1.333.rationalize(0.01) #=> (4/3)
See also Float#to_r.
Returns an exception object of the same class as self; useful for creating a similar exception, but with a different message.
With message nil, returns self:
x0 = StandardError.new('Boom') # => #<StandardError: Boom> x1 = x0.exception # => #<StandardError: Boom> x0.__id__ == x1.__id__ # => true
With string-convertible object message (even the same as the original message), returns a new exception object whose class is the same as self, and whose message is the given message:
x1 = x0.exception('Boom') # => #<StandardError: Boom> x0..equal?(x1) # => false
Returns an exception object of the same class as self; useful for creating a similar exception, but with a different message.
With message nil, returns self:
x0 = StandardError.new('Boom') # => #<StandardError: Boom> x1 = x0.exception # => #<StandardError: Boom> x0.__id__ == x1.__id__ # => true
With string-convertible object message (even the same as the original message), returns a new exception object whose class is the same as self, and whose message is the given message:
x1 = x0.exception('Boom') # => #<StandardError: Boom> x0..equal?(x1) # => false
Returns a simpler approximation of the value if the optional argument eps is given (rat-|eps| <= result <= rat+|eps|), self otherwise.
r = Rational(5033165, 16777216) r.rationalize #=> (5033165/16777216) r.rationalize(Rational('0.01')) #=> (3/10) r.rationalize(Rational('0.1')) #=> (1/3)
Returns a new regexp that is the union of the given patterns:
r = Regexp.union(%w[cat dog]) # => /cat|dog/ r.match('cat') # => #<MatchData "cat"> r.match('dog') # => #<MatchData "dog"> r.match('cog') # => nil
For each pattern that is a string, Regexp.new(pattern) is used:
Regexp.union('penzance') # => /penzance/ Regexp.union('a+b*c') # => /a\+b\*c/ Regexp.union('skiing', 'sledding') # => /skiing|sledding/ Regexp.union(['skiing', 'sledding']) # => /skiing|sledding/
For each pattern that is a regexp, it is used as is, including its flags:
Regexp.union(/foo/i, /bar/m, /baz/x) # => /(?i-mx:foo)|(?m-ix:bar)|(?x-mi:baz)/ Regexp.union([/foo/i, /bar/m, /baz/x]) # => /(?i-mx:foo)|(?m-ix:bar)|(?x-mi:baz)/
With no arguments, returns /(?!)/:
Regexp.union # => /(?!)/
If any regexp pattern contains captures, the behavior is unspecified.
Returns an integer whose bits show the options set in self.
The option bits are:
Regexp::IGNORECASE # => 1 Regexp::EXTENDED # => 2 Regexp::MULTILINE # => 4
Examples:
/foo/.options # => 0 /foo/i.options # => 1 /foo/x.options # => 2 /foo/m.options # => 4 /foo/mix.options # => 7
Note that additional bits may be set in the returned integer; these are maintained internally in self, are ignored if passed to Regexp.new, and may be ignored by the caller:
Returns the set of bits corresponding to the options used when creating this regexp (see Regexp::new for details). Note that additional bits may be set in the returned options: these are used internally by the regular expression code. These extra bits are ignored if the options are passed to Regexp::new:
r = /\xa1\xa2/e # => /\xa1\xa2/ r.source # => "\\xa1\\xa2" r.options # => 16 Regexp.new(r.source, r.options) # => /\xa1\xa2/
Sets optional filename and line number that will be used in ERB code evaluation and error reporting. See also filename= and lineno=
erb = ERB.new('<%= some_x %>') erb.render # undefined local variable or method `some_x' # from (erb):1 erb.location = ['file.erb', 3] # All subsequent error reporting would use new location erb.render # undefined local variable or method `some_x' # from file.erb:4
Returns x/y or arg as a Rational.
Rational(2, 3) #=> (2/3) Rational(5) #=> (5/1) Rational(0.5) #=> (1/2) Rational(0.3) #=> (5404319552844595/18014398509481984) Rational("2/3") #=> (2/3) Rational("0.3") #=> (3/10) Rational("10 cents") #=> ArgumentError Rational(nil) #=> TypeError Rational(1, nil) #=> TypeError Rational("10 cents", exception: false) #=> nil
Syntax of the string form:
string form = extra spaces , rational , extra spaces ;
rational = [ sign ] , unsigned rational ;
unsigned rational = numerator | numerator , "/" , denominator ;
numerator = integer part | fractional part | integer part , fractional part ;
denominator = digits ;
integer part = digits ;
fractional part = "." , digits , [ ( "e" | "E" ) , [ sign ] , digits ] ;
sign = "-" | "+" ;
digits = digit , { digit | "_" , digit } ;
digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" ;
extra spaces = ? \s* ? ;
See also String#to_r.
Returns an array of the string keyword names:
FileUtils.options.take(3) # => ["noop", "verbose", "force"]
Sets the Fiber scheduler for the current thread. If the scheduler is set, non-blocking fibers (created by Fiber.new with blocking: false, or by Fiber.schedule) call that scheduler’s hook methods on potentially blocking operations, and the current thread will call scheduler’s close method on finalization (allowing the scheduler to properly manage all non-finished fibers).
scheduler can be an object of any class corresponding to Fiber::Scheduler. Its implementation is up to the user.
See also the “Non-blocking fibers” section in class docs.
Returns the Fiber scheduler, that was last set for the current thread with Fiber.set_scheduler if and only if the current fiber is non-blocking.
Foo::Bar += baz ^^^^^^^^^^^^^^^