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.
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)
Return a Regexp object that is the union of the given patterns, i.e., will match any of its parts. The patterns can be Regexp objects, in which case their options will be preserved, or Strings. If no patterns are given, returns /(?!)/. The behavior is unspecified if any given pattern contains capture.
Regexp.union #=> /(?!)/ Regexp.union("penzance") #=> /penzance/ Regexp.union("a+b*c") #=> /a\+b\*c/ Regexp.union("skiing", "sledding") #=> /skiing|sledding/ Regexp.union(["skiing", "sledding"]) #=> /skiing|sledding/ Regexp.union(/dogs/, /cats/i) #=> /(?-mix:dogs)|(?i-mx:cats)/
Note: the arguments for ::union will try to be converted into a regular expression literal via to_regexp.
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.
Regexp::IGNORECASE #=> 1 Regexp::EXTENDED #=> 2 Regexp::MULTILINE #=> 4 /cat/.options #=> 0 /cat/ix.options #=> 3 Regexp.new('cat', true).options #=> 1 /\xa1\xa2/e.options #=> 16 r = /cat/ix Regexp.new(r.source, r.options) #=> /cat/ix
Returns true if argument is optional.
tobj = WIN32OLE_TYPE.new('Microsoft Excel 9.0 Object Library', 'Workbook') method = WIN32OLE_METHOD.new(tobj, 'SaveAs') param1 = method.params[0] puts "#{param1.name} #{param1.optional?}" # => Filename true
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 the options bitmask used in the last call to open()
Returns an Array of option names.
p FileUtils.options #=> ["noop", "force", "verbose", "preserve", "mode"]
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::SchedulerInterface. 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.
Get the names of all sections in the current configuration.
Creates or an HTTP connection based on uri, or retrieves an existing connection, using a proxy if needed.