Returns default internal encoding. Strings will be transcoded to the default internal encoding in the following places if the default internal encoding is not nil:
CSV
File data read from disk
Strings returned from Readline
Strings returned from SDBM
Values from ENV
Values in ARGV including $PROGRAM_NAME
Additionally String#encode and String#encode! use the default internal encoding if no encoding is given.
The script encoding (__ENCODING__), not default_internal, is used as the encoding of created strings.
Encoding::default_internal is initialized with -E option or nil otherwise.
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.
See class-level notes about external iterators.
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]
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.
See class-level notes about external iterators.
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 an array of instance variable names for the receiver. Note that simply defining an accessor does not create the corresponding instance variable.
class Fred attr_accessor :a1 def initialize @iv = 3 end end Fred.new.instance_variables #=> [:@iv]
Returns true if obj is an instance of the given class. See also Object#kind_of?.
class A; end class B < A; end class C < B; end b = B.new b.instance_of? A #=> false b.instance_of? B #=> true b.instance_of? C #=> false
Returns the message string with enhancements:
Includes the exception class name in the first line.
If the value of keyword highlight is true, includes bolding and underlining ANSI codes (see below) to enhance the appearance of the message.
Examples:
begin 1 / 0 rescue => x p x.message p x.detailed_message # Class name added. p x.detailed_message(highlight: true) # Class name, bolding, and underlining added. end
Output:
"divided by 0" "divided by 0 (ZeroDivisionError)" "\e[1mdivided by 0 (\e[1;4mZeroDivisionError\e[m\e[1m)\e[m"
This method is overridden by some gems in the Ruby standard library to add information:
An overriding method must be tolerant of passed keyword arguments, which may include (but may not be limited to):
:highlight.
:did_you_mean.
:error_highlight.
:syntax_suggest.
An overriding method should also be careful with ANSI code enhancements; see Messages.
Returns an enhanced message string:
Includes the exception class name.
If the value of keyword highlight is true (not nil or false), includes bolding ANSI codes (see below) to enhance the appearance of the message.
Includes the backtrace:
If the value of keyword order is :top (the default), lists the error message and the innermost backtrace entry first.
If the value of keyword order is :bottom, lists the error message the the innermost entry last.
Example:
def baz begin 1 / 0 rescue => x pp x.message pp x.full_message(highlight: false).split("\n") pp x.full_message.split("\n") end end def bar; baz; end def foo; bar; end foo
Output:
"divided by 0" ["t.rb:3:in 'Integer#/': divided by 0 (ZeroDivisionError)", "\tfrom t.rb:3:in 'Object#baz'", "\tfrom t.rb:10:in 'Object#bar'", "\tfrom t.rb:11:in 'Object#foo'", "\tfrom t.rb:12:in '<main>'"] ["t.rb:3:in 'Integer#/': \e[1mdivided by 0 (\e[1;4mZeroDivisionError\e[m\e[1m)\e[m", "\tfrom t.rb:3:in 'Object#baz'", "\tfrom t.rb:10:in 'Object#bar'", "\tfrom t.rb:11:in 'Object#foo'", "\tfrom t.rb:12:in '<main>'"]
An overriding method should be careful with ANSI code enhancements; see backtrace.
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
Note that method visibility changes in the current class, as well as aliases, are considered as methods of the current class by this method:
class C < B alias method4 method2 protected :method2 end C.instance_methods(false).sort #=> [:method2, :method3, :method4]
Makes a list of existing constants public.
Makes a list of existing constants private.
Makes a list of existing constants deprecated. Attempt to refer to them will produce a warning.
module HTTP NotFound = Exception.new NOT_FOUND = NotFound # previous version of the library used this name deprecate_constant :NOT_FOUND end HTTP::NOT_FOUND # warning: constant HTTP::NOT_FOUND is 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 #=> :orig_exit def exit(code=0) puts "Exiting with code #{code}" orig_exit(code) end end include Mod exit(99)
produces:
Exiting with code 99
Implemented for compatibility; returns true unless jd is invalid (i.e., not a Numeric).
Date.valid_jd?(2451944) # => true
See argument start.
Related: Date.jd.
Returns true if the arguments define a valid ordinal date, false otherwise:
Date.valid_date?(2001, 2, 3) # => true Date.valid_date?(2001, 2, 29) # => false Date.valid_date?(2001, 2, -1) # => true
See argument start.
Returns true if the arguments define a valid ordinal date, false otherwise:
Date.valid_date?(2001, 2, 3) # => true Date.valid_date?(2001, 2, 29) # => false Date.valid_date?(2001, 2, -1) # => true
See argument start.
Returns a copy of self with the given start value:
d0 = Date.new(2000, 2, 3) d0.julian? # => false d1 = d0.new_start(Date::JULIAN) d1.julian? # => true
See argument start.
Scrolls the entire scrolls forward n lines.
You must require ‘io/console’ to use this method.
Scrolls the entire scrolls backward n lines.
You must require ‘io/console’ to use this method.