Like String#unicode_normalize
, except that the normalization is performed on self
.
Related String#unicode_normalized?
.
Returns true
if self
is in the given form
of Unicode normalization, false
otherwise. The form
must be one of :nfc
, :nfd
, :nfkc
, or :nfkd
.
Examples:
"a\u0300".unicode_normalized? # => false "a\u0300".unicode_normalized?(:nfd) # => true "\u00E0".unicode_normalized? # => true "\u00E0".unicode_normalized?(:nfd) # => false
Raises an exception if self
is not in a Unicode encoding:
s = "\xE0".force_encoding('ISO-8859-1') s.unicode_normalized? # Raises Encoding::CompatibilityError.
Related: String#unicode_normalize
, String#unicode_normalize!
.
Returns true
if the named file is readable by the real user and group id of this process. See access(3).
Note that some OS-level security features may cause this to return true even though the file is not readable by the real user/group.
If file_name is writable by others, returns an integer representing the file permission bits of file_name. Returns nil
otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat(2)
.
file_name can be an IO
object.
File.world_writable?("/tmp") #=> 511 m = File.world_writable?("/tmp") sprintf("%o", m) #=> "777"
Returns default external encoding.
The default external encoding is used by default for strings created from the following locations:
CSV
File
data read from disk
SDBM
While strings created from these locations will have this encoding, the encoding may not be valid. Be sure to check String#valid_encoding?
.
File
data written to disk will be transcoded to the default external encoding when written, if default_internal
is not nil.
The default external encoding is initialized by the -E option. If -E isn’t set, it is initialized to UTF-8 on Windows and the locale on other operating systems.
Sets default external encoding. You should not set Encoding::default_external
in ruby code as strings created before changing the value may have a different encoding from strings created after the value was changed., instead you should use ruby -E
to invoke ruby with the correct default_external.
See Encoding::default_external
for information on how the default external encoding is used.
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
Processes a string returned by message
.
It may add the class name of the exception to the end of the first line. Also, when highlight
keyword is true, it adds ANSI escape sequences to make the message bold.
If you override this method, it must be tolerant for unknown keyword arguments. All keyword arguments passed to full_message
are delegated to this method.
This method is overridden by did_you_mean and error_highlight to add their information.
A user-defined exception class can also define their own detailed_message
method to add supplemental information. When highlight
is true, it can return a string containing escape sequences, but use widely-supported ones. It is recommended to limit the following codes:
Reset (\e[0m
)
Bold (\e[1m
)
Underline (\e[4m
)
Foreground color except white and black
Red (\e[31m
)
Green (\e[32m
)
Yellow (\e[33m
)
Blue (\e[34m
)
Magenta (\e[35m
)
Cyan (\e[36m
)
Use escape sequences carefully even if highlight
is true. Do not use escape sequences to express essential information; the message should be readable even if all escape sequences are ignored.
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
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