Results for: "OptionParser"

Returns a new Array containing zero or more trailing elements of self; does not modify self.

With a block given, calls the block with each successive element of self; stops if the block returns false or nil; returns a new Array omitting those elements for which the block returned a truthy value:

a = [0, 1, 2, 3, 4, 5]
a.drop_while {|element| element < 3 } # => [3, 4, 5]

With no block given, returns a new Enumerator:

[0, 1].drop_while # => # => #<Enumerator: [0, 1]:drop_while>

See as_json.

Methods Complex#as_json and Complex.json_create may be used to serialize and deserialize a Complex object; see Marshal.

Method Complex#as_json serializes self, returning a 2-element hash representing self:

require 'json/add/complex'
x = Complex(2).as_json      # => {"json_class"=>"Complex", "r"=>2, "i"=>0}
y = Complex(2.0, 4).as_json # => {"json_class"=>"Complex", "r"=>2.0, "i"=>4}

Method JSON.create deserializes such a hash, returning a Complex object:

Complex.json_create(x) # => (2+0i)
Complex.json_create(y) # => (2.0+4i)

Returns a JSON string representing self:

require 'json/add/complex'
puts Complex(2).to_json
puts Complex(2.0, 4).to_json

Output:

{"json_class":"Complex","r":2,"i":0}
{"json_class":"Complex","r":2.0,"i":4}

Returns whether self starts with any of the given string_or_regexp.

Matches patterns against the beginning of self. For each given string_or_regexp, the pattern is:

• string_or_regexp itself, if it is a Regexp.

• Regexp.quote(string_or_regexp), if string_or_regexp is a string.

Returns true if any pattern matches the beginning, false otherwise:

'hello'.start_with?('hell')               # => true
'hello'.start_with?(/H/i)                 # => true
'hello'.start_with?('heaven', 'hell')     # => true
'hello'.start_with?('heaven', 'paradise') # => false
'тест'.start_with?('т')                   # => true
'こんにちは'.start_with?('こ')              # => true

Related: String#end_with?.

Calls the given block with each successive character from self; returns self:

'hello'.each_char {|char| print char, ' ' }
print "\n"
'тест'.each_char {|char| print char, ' ' }
print "\n"
'こんにちは'.each_char {|char| print char, ' ' }
print "\n"

Output:

h e l l o
т е с т
こ ん に ち は

Returns an enumerator if no block is given.

Returns true if self contains only ASCII characters, false otherwise:

'abc'.ascii_only?         # => true
"abc\u{6666}".ascii_only? # => false

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.

Returns the dirpath string that was used to create self (or nil if created by method Dir.for_fd):

Dir.new('example').path # => "example"

Converts a pathname to an absolute pathname. Relative paths are referenced from the current working directory of the process unless dir_string is given, in which case it will be used as the starting point. If the given pathname starts with a “~” it is NOT expanded, it is treated as a normal directory name.

File.absolute_path("~oracle/bin")       #=> "<relative_path>/~oracle/bin"

Returns true if file_name is an absolute path, and false otherwise.

File.absolute_path?("c:/foo")     #=> false (on Linux), true (on Windows)

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

• StringIO

• Zlib::GzipReader

• Zlib::GzipWriter

• String#inspect

• Regexp#inspect

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

• Etc.sysconfdir and Etc.systmpdir

• File data read from disk

• File names from Dir

• Integer#chr

• String#inspect and Regexp#inspect

• Strings returned from Readline

• Strings returned from SDBM

• Time#zone

• 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 singleton class of obj. This method creates a new singleton class if obj does not have one.

If obj is nil, true, or false, it returns NilClass, TrueClass, or FalseClass, respectively. If obj is an Integer, a Float or a Symbol, it raises a TypeError.

Object.new.singleton_class  #=> #<Class:#<Object:0xb7ce1e24>>
String.singleton_class      #=> #<Class:String>
nil.singleton_class         #=> NilClass

Returns an array of the names of singleton methods for obj. If the optional all parameter is true, the list will include methods in modules included in obj. Only public and protected singleton methods are returned.

module Other
  def three() end
end

class Single
  def Single.four() end
end

a = Single.new

def a.one()
end

class << a
  include Other
  def two()
  end
end

Single.singleton_methods    #=> [:four]
a.singleton_methods(false)  #=> [:two, :one]
a.singleton_methods         #=> [:two, :one, :three]

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]

Similar to method, searches singleton method only.

class Demo
  def initialize(n)
    @iv = n
  end
  def hello()
    "Hello, @iv = #{@iv}"
  end
end

k = Demo.new(99)
def k.hi
  "Hi, @iv = #{@iv}"
end
m = k.singleton_method(:hi)
m.call   #=> "Hi, @iv = 99"
m = k.singleton_method(:hello) #=> NameError

Invokes the method identified by symbol, passing it any arguments specified. Unlike send, public_send calls public methods only. When the method is identified by a string, the string is converted to a symbol.

1.public_send(:puts, "hello")  # causes NoMethodError

Returns true if obj responds to the given method. Private and protected methods are included in the search only if the optional second parameter evaluates to true.

If the method is not implemented, as Process.fork on Windows, File.lchmod on GNU/Linux, etc., false is returned.

If the method is not defined, respond_to_missing? method is called and the result is returned.

When the method name parameter is given as a string, the string is converted to a symbol.

Sets the backtrace information associated with exc. The backtrace must be an array of String objects or a single String in the format described in Exception#backtrace.

See as_json.

Methods Exception#as_json and Exception.json_create may be used to serialize and deserialize a Exception object; see Marshal.

Method Exception#as_json serializes self, returning a 2-element hash representing self:

require 'json/add/exception'
x = Exception.new('Foo').as_json # => {"json_class"=>"Exception", "m"=>"Foo", "b"=>nil}

Method JSON.create deserializes such a hash, returning a Exception object:

Exception.json_create(x) # => #<Exception: Foo>