Sets default internal encoding or removes default internal encoding when passed nil. You should not set Encoding::default_internal in ruby code as strings created before changing the value may have a different encoding from strings created after the change. Instead you should use ruby -E to invoke ruby with the correct default_internal.
See Encoding::default_internal for information on how the default internal encoding is used.
Returns the locale charmap name. It returns nil if no appropriate information.
Debian GNU/Linux LANG=C Encoding.locale_charmap #=> "ANSI_X3.4-1968" LANG=ja_JP.EUC-JP Encoding.locale_charmap #=> "EUC-JP" SunOS 5 LANG=C Encoding.locale_charmap #=> "646" LANG=ja Encoding.locale_charmap #=> "eucJP"
The result is highly platform dependent. So Encoding.find(Encoding.locale_charmap) may cause an error. If you need some encoding object even for unknown locale, Encoding.find(“locale”) can be used.
Returns the next object as an array in the enumerator, and move the internal position forward. When the position reached at the end, StopIteration is raised.
This method can be used to distinguish yield and yield nil.
o = Object.new def o.each yield yield 1 yield 1, 2 yield nil yield [1, 2] end e = o.to_enum p e.next_values p e.next_values p e.next_values p e.next_values p e.next_values e = o.to_enum p e.next p e.next p e.next p e.next p e.next ## yield args next_values next # yield [] nil # yield 1 [1] 1 # yield 1, 2 [1, 2] [1, 2] # yield nil [nil] nil # yield [1, 2] [[1, 2]] [1, 2]
Note that next_values does not affect other non-external enumeration methods unless underlying iteration method itself has side-effect, e.g. IO#each_line.
Returns the next object as an array, similar to Enumerator#next_values, but doesn’t move the internal position forward. If the position is already at the end, StopIteration is raised.
o = Object.new def o.each yield yield 1 yield 1, 2 end e = o.to_enum p e.peek_values #=> [] e.next p e.peek_values #=> [1] p e.peek_values #=> [1] e.next p e.peek_values #=> [1, 2] e.next p e.peek_values # raises StopIteration
Returns formatted string of exception. The returned string is formatted using the same format that Ruby uses when printing an uncaught exceptions to stderr.
If highlight is true the default error handler will send the messages to a tty.
order must be either of :top or :bottom, and places the error message and the innermost backtrace come at the top or the bottom.
The default values of these options depend on $stderr and its tty? at the timing of a call.
Return a list of the local variable names defined where this NameError exception was raised.
Internal use only.
Returns an array containing the names of the public and protected instance methods in the receiver. For a module, these are the public and protected methods; for a class, they are the instance (not singleton) methods. If the optional parameter is false, the methods of any ancestors are not included.
module A def method1() end end class B include A def method2() end end class C < B def method3() end end A.instance_methods(false) #=> [:method1] B.instance_methods(false) #=> [:method2] B.instance_methods(true).include?(:method1) #=> true C.instance_methods(false) #=> [:method3] C.instance_methods.include?(:method2) #=> true
Makes a list of existing constants public.
Makes a list of existing constants private.
Makes a list of existing constants deprecated.
Returns an UnboundMethod representing the given instance method in mod.
class Interpreter def do_a() print "there, "; end def do_d() print "Hello "; end def do_e() print "!\n"; end def do_v() print "Dave"; end Dispatcher = { "a" => instance_method(:do_a), "d" => instance_method(:do_d), "e" => instance_method(:do_e), "v" => instance_method(:do_v) } def interpret(string) string.each_char {|b| Dispatcher[b].bind(self).call } end end interpreter = Interpreter.new interpreter.interpret('dave')
produces:
Hello there, Dave!
Evaluates the string or block in the context of mod, except that when a block is given, constant/class variable lookup is not affected. This can be used to add methods to a class. module_eval returns the result of evaluating its argument. The optional filename and lineno parameters set the text for error messages.
class Thing end a = %q{def hello() "Hello there!" end} Thing.module_eval(a) puts Thing.new.hello() Thing.module_eval("invalid code", "dummy", 123)
produces:
Hello there!
dummy:123:in `module_eval': undefined local variable
or method `code' for Thing:Class
Evaluates the string or block in the context of mod, except that when a block is given, constant/class variable lookup is not affected. This can be used to add methods to a class. module_eval returns the result of evaluating its argument. The optional filename and lineno parameters set the text for error messages.
class Thing end a = %q{def hello() "Hello there!" end} Thing.module_eval(a) puts Thing.new.hello() Thing.module_eval("invalid code", "dummy", 123)
produces:
Hello there!
dummy:123:in `module_eval': undefined local variable
or method `code' for Thing:Class
Makes new_name a new copy of the method old_name. This can be used to retain access to methods that are overridden.
module Mod alias_method :orig_exit, :exit def exit(code=0) puts "Exiting with code #{code}" orig_exit(code) end end include Mod exit(99)
produces:
Exiting with code 99
Just returns true. It’s nonsense, but is for symmetry.
Date.valid_jd?(2451944) #=> true
See also ::jd.
Returns true if the given calendar date is valid, and false if not.
Date.valid_date?(2001,2,3) #=> true Date.valid_date?(2001,2,29) #=> false
Returns true if the given calendar date is valid, and false if not.
Date.valid_date?(2001,2,3) #=> true Date.valid_date?(2001,2,29) #=> false
Duplicates self and resets its day of calendar reform.
d = Date.new(1582,10,15) d.new_start(Date::JULIAN) #=> #<Date: 1582-10-05 ...>
Returns an array containing the values associated with the given keys.
Calls the block once for each value string in the database. Returns self.
Returns true if the database contains the specified string value, false otherwise.
Returns the struct member values for each selector as an Array. A selector may be either an Integer offset or a Range of offsets (as in Array#values_at).
Customer = Struct.new(:name, :address, :zip) joe = Customer.new("Joe Smith", "123 Maple, Anytown NC", 12345) joe.values_at(0, 2) #=> ["Joe Smith", 12345]