Returns a 2-element array containing other
converted to a Float and self
:
f = 3.14 # => 3.14 f.coerce(2) # => [2.0, 3.14] f.coerce(2.0) # => [2.0, 3.14] f.coerce(Rational(1, 2)) # => [0.5, 3.14] f.coerce(Complex(1, 0)) # => [1.0, 3.14]
Raises an exception if a type conversion fails.
Returns a string containing a representation of self
; depending of the value of self
, the string representation may contain:
A fixed-point number.
A number in “scientific notation” (containing an exponent).
‘Infinity’.
‘-Infinity’.
‘NaN’ (indicating not-a-number).
3.14.to_s # => “3.14” (10.1**50).to_s # => “1.644631821843879e+50” (10.1**500).to_s # => “Infinity” (-10.1**500).to_s # => “-Infinity” (0.0/0.0).to_s # => “NaN”
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
.
Transfer control to another fiber, resuming it from where it last stopped or starting it if it was not resumed before. The calling fiber will be suspended much like in a call to Fiber.yield
.
The fiber which receives the transfer call treats it much like a resume call. Arguments passed to transfer are treated like those passed to resume.
The two style of control passing to and from fiber (one is resume
and Fiber::yield
, another is transfer
to and from fiber) can’t be freely mixed.
If the Fiber’s lifecycle had started with transfer, it will never be able to yield or be resumed control passing, only finish or transfer back. (It still can resume other fibers that are allowed to be resumed.)
If the Fiber’s lifecycle had started with resume, it can yield or transfer to another Fiber
, but can receive control back only the way compatible with the way it was given away: if it had transferred, it only can be transferred back, and if it had yielded, it only can be resumed back. After that, it again can transfer or yield.
If those rules are broken FiberError
is raised.
For an individual Fiber
design, yield/resume is easier to use (the Fiber
just gives away control, it doesn’t need to think about who the control is given to), while transfer is more flexible for complex cases, allowing to build arbitrary graphs of Fibers dependent on each other.
Example:
manager = nil # For local var to be visible inside worker block # This fiber would be started with transfer # It can't yield, and can't be resumed worker = Fiber.new { |work| puts "Worker: starts" puts "Worker: Performed #{work.inspect}, transferring back" # Fiber.yield # this would raise FiberError: attempt to yield on a not resumed fiber # manager.resume # this would raise FiberError: attempt to resume a resumed fiber (double resume) manager.transfer(work.capitalize) } # This fiber would be started with resume # It can yield or transfer, and can be transferred # back or resumed manager = Fiber.new { puts "Manager: starts" puts "Manager: transferring 'something' to worker" result = worker.transfer('something') puts "Manager: worker returned #{result.inspect}" # worker.resume # this would raise FiberError: attempt to resume a transferring fiber Fiber.yield # this is OK, the fiber transferred from and to, now it can yield puts "Manager: finished" } puts "Starting the manager" manager.resume puts "Resuming the manager" # manager.transfer # this would raise FiberError: attempt to transfer to a yielding fiber manager.resume
produces
Starting the manager Manager: starts Manager: transferring 'something' to worker Worker: starts Worker: Performed "something", transferring back Manager: worker returned "Something" Resuming the manager Manager: finished
Return a string describing this Dir
object.
Returns true
if the named file is a directory, false
otherwise.
Returns a File::Stat
object for the named file (see File::Stat
).
File.stat("testfile").mtime #=> Tue Apr 08 12:58:04 CDT 2003
Same as File::stat
, but does not follow the last symbolic link. Instead, reports on the link itself.
File.symlink("testfile", "link2test") #=> 0 File.stat("testfile").size #=> 66 File.lstat("link2test").size #=> 8 File.stat("link2test").size #=> 66
Same as IO#stat
, but does not follow the last symbolic link. Instead, reports on the link itself.
File.symlink("testfile", "link2test") #=> 0 File.stat("testfile").size #=> 66 f = File.new("link2test") f.lstat.size #=> 8 f.stat.size #=> 66
Return true
if the named file exists.
file_name can be an IO
object.
“file exists” means that stat() or fstat() system call is successful.
Returns a string which represents the encoding for programmers.
Encoding::UTF_8.inspect #=> "#<Encoding:UTF-8>" Encoding::ISO_2022_JP.inspect #=> "#<Encoding:ISO-2022-JP (dummy)>"
Returns the list of loaded encodings.
Encoding.list #=> [#<Encoding:ASCII-8BIT>, #<Encoding:UTF-8>, #<Encoding:ISO-2022-JP (dummy)>] Encoding.find("US-ASCII") #=> #<Encoding:US-ASCII> Encoding.list #=> [#<Encoding:ASCII-8BIT>, #<Encoding:UTF-8>, #<Encoding:US-ASCII>, #<Encoding:ISO-2022-JP (dummy)>]
Checks the compatibility of two objects.
If the objects are both strings they are compatible when they are concatenatable. The encoding of the concatenated string will be returned if they are compatible, nil if they are not.
Encoding.compatible?("\xa1".force_encoding("iso-8859-1"), "b") #=> #<Encoding:ISO-8859-1> Encoding.compatible?( "\xa1".force_encoding("iso-8859-1"), "\xa1\xa1".force_encoding("euc-jp")) #=> nil
If the objects are non-strings their encodings are compatible when they have an encoding and:
Either encoding is US-ASCII compatible
One of the encodings is a 7-bit encoding
Creates a printable version of e.
With no argument, or if the argument is the same as the receiver, return the receiver. Otherwise, create a new exception object of the same class as the receiver, but with a message equal to string.to_str
.
With no argument, or if the argument is the same as the receiver, return the receiver. Otherwise, create a new exception object of the same class as the receiver, but with a message equal to string.to_str
.
Return this exception’s class name and message.
Return the status value associated with this system exit.
Returns the list of Modules
nested at the point of call.
module M1 module M2 $a = Module.nesting end end $a #=> [M1::M2, M1] $a[0].name #=> "M1::M2"
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 string representing this module or class. For basic classes and modules, this is the name. For singletons, we show information on the thing we’re attached to as well.
Returns self if the value is non-zero, nil otherwise.