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
. You need to require 'fiber'
before using this method.
The fiber which receives the transfer call is treats it much like a resume call. Arguments passed to transfer are treated like those passed to resume.
You cannot resume a fiber that transferred control to another one. This will cause a double resume error. You need to transfer control back to this fiber before it can yield and resume.
Example:
fiber1 = Fiber.new do puts "In Fiber 1" Fiber.yield end fiber2 = Fiber.new do puts "In Fiber 2" fiber1.transfer puts "Never see this message" end fiber3 = Fiber.new do puts "In Fiber 3" end fiber2.resume fiber3.resume
produces
In fiber 2 In fiber 1 In fiber 3
Returns the current fiber. You need to require 'fiber'
before using this method. If you are not running in the context of a fiber this method will return the root fiber.
Repositions dir to the first entry.
d = Dir.new("testdir") d.read #=> "." d.rewind #=> #<Dir:0x401b3fb0> d.read #=> "."
Returns true
if the named file exists and the effective used id of the calling process is the owner of the file.
file_name can be an IO
object.
Returns true
if the named file exists and the effective group id of the calling process is the owner of the file. Returns false
on Windows.
file_name can be an IO
object.
Returns the next object in the enumerator, and move the internal position forward. When the position reached at the end, StopIteration
is raised.
a = [1,2,3] e = a.to_enum p e.next #=> 1 p e.next #=> 2 p e.next #=> 3 p e.next #raises StopIteration
Note that enumeration sequence by next
does not affect other non-external enumeration methods, unless the underlying iteration methods itself has side-effect, e.g. IO#each_line
.
Rewinds the enumeration sequence to the beginning.
If the enclosed object responds to a “rewind” method, it is called.
Returns any backtrace associated with the exception. The backtrace is an array of strings, each containing either “filename:lineNo: in ‘method”’ or “filename:lineNo.”
def a raise "boom" end def b a() end begin b() rescue => detail print detail.backtrace.join("\n") end
produces:
prog.rb:2:in `a' prog.rb:6:in `b' prog.rb:10
Return the arguments passed in as the third parameter to the constructor.
Return this SystemCallError’s error number.
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"
Return the fractional part of the number, as a BigDecimal
.
Returns the exponent of the BigDecimal
number, as an Integer
.
If the number can be represented as 0.xxxxxx*10**n where xxxxxx is a string of digits with no leading zeros, then n is the exponent.
Returns the numerator.
Rational(7).numerator #=> 7 Rational(7, 1).numerator #=> 7 Rational(9, -4).numerator #=> -9 Rational(-2, -10).numerator #=> 1
Returns true
if rat
is less than 0.
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)
Parses the given representation of date and time, and returns a hash of parsed elements. This method does not function as a validator.
If the optional second argument is true and the detected year is in the range “00” to “99”, considers the year a 2-digit form and makes it full.
Date._parse('2001-02-03') #=> {:year=>2001, :mon=>2, :mday=>3}
Parses the given representation of date and time, and creates a date object. This method does not function as a validator.
If the optional second argument is true and the detected year is in the range “00” to “99”, considers the year a 2-digit form and makes it full.
Date.parse('2001-02-03') #=> #<Date: 2001-02-03 ...> Date.parse('20010203') #=> #<Date: 2001-02-03 ...> Date.parse('3rd Feb 2001') #=> #<Date: 2001-02-03 ...>