Results for: "remove_const"

Removes the definition of the given constant, returning that constant’s previous value. If that constant referred to a module, this will not change that module’s name and can lead to confusion.

Removes the last List.

Returns whether or not the constant const is defined. You may optionally pass the type of const as [const, type], such as:

have_const(%w[PTHREAD_MUTEX_INITIALIZER pthread_mutex_t], "pthread.h")

You may also pass additional headers to check against in addition to the common header files, and additional flags to opt which are then passed along to the compiler.

If found, a macro is passed as a preprocessor constant to the compiler using the type name, in uppercase, prepended with HAVE_CONST_.

For example, if have_const('foo') returned true, then the HAVE_CONST_FOO preprocessor macro would be passed to the compiler.

Removes server from the list of registered servers.

Removes server from the list of registered servers.

Removes the method identified by symbol from the current class. For an example, see Module#undef_method. String arguments are converted to symbols.

This method removes a file system entry path. path might be a regular file, a directory, or something. If path is a directory, remove it recursively.

See also remove_entry_secure.

This method removes a file system entry path. path might be a regular file, a directory, or something. If path is a directory, remove it recursively.

See also remove_entry_secure.

Removes a file path. This method ignores StandardError if force is true.

Removes a file path. This method ignores StandardError if force is true.

Removes a directory dir and its contents recursively. This method ignores StandardError if force is true.

Removes a directory dir and its contents recursively. This method ignores StandardError if force is true.

spec

the spec of the gem to be uninstalled

Removes the named instance variable from obj, returning that variable’s value. String arguments are converted to symbols.

class Dummy
  attr_reader :var
  def initialize
    @var = 99
  end
  def remove
    remove_instance_variable(:@var)
  end
end
d = Dummy.new
d.var      #=> 99
d.remove   #=> 99
d.var      #=> nil

Checks for a constant with the given name in mod. If inherit is set, the lookup will also search the ancestors (and Object if mod is a Module).

The value of the constant is returned if a definition is found, otherwise a NameError is raised.

Math.const_get(:PI)   #=> 3.14159265358979

This method will recursively look up constant names if a namespaced class name is provided. For example:

module Foo; class Bar; end end
Object.const_get 'Foo::Bar'

The inherit flag is respected on each lookup. For example:

module Foo
  class Bar
    VAL = 10
  end

  class Baz < Bar; end
end

Object.const_get 'Foo::Baz::VAL'         # => 10
Object.const_get 'Foo::Baz::VAL', false  # => NameError

If the argument is not a valid constant name a NameError will be raised with a warning “wrong constant name”.

Object.const_get 'foobar' #=> NameError: wrong constant name foobar

Sets the named constant to the given object, returning that object. Creates a new constant if no constant with the given name previously existed.

Math.const_set("HIGH_SCHOOL_PI", 22.0/7.0)   #=> 3.14285714285714
Math::HIGH_SCHOOL_PI - Math::PI              #=> 0.00126448926734968

If sym or str is not a valid constant name a NameError will be raised with a warning “wrong constant name”.

Object.const_set('foobar', 42) #=> NameError: wrong constant name foobar

Says whether mod or its ancestors have a constant with the given name:

Float.const_defined?(:EPSILON)      #=> true, found in Float itself
Float.const_defined?("String")      #=> true, found in Object (ancestor)
BasicObject.const_defined?(:Hash)   #=> false

If mod is a Module, additionally Object and its ancestors are checked:

Math.const_defined?(:String)   #=> true, found in Object

In each of the checked classes or modules, if the constant is not present but there is an autoload for it, true is returned directly without autoloading:

module Admin
  autoload :User, 'admin/user'
end
Admin.const_defined?(:User)   #=> true

If the constant is not found the callback const_missing is not called and the method returns false.

If inherit is false, the lookup only checks the constants in the receiver:

IO.const_defined?(:SYNC)          #=> true, found in File::Constants (ancestor)
IO.const_defined?(:SYNC, false)   #=> false, not found in IO itself

In this case, the same logic for autoloading applies.

If the argument is not a valid constant name a NameError is raised with the message “wrong constant name name”:

Hash.const_defined? 'foobar'   #=> NameError: wrong constant name foobar

Invoked when a reference is made to an undefined constant in mod. It is passed a symbol for the undefined constant, and returns a value to be used for that constant. The following code is an example of the same:

def Foo.const_missing(name)
  name # return the constant name as Symbol
end

Foo::UNDEFINED_CONST    #=> :UNDEFINED_CONST: symbol returned

In the next example when a reference is made to an undefined constant, it attempts to load a file whose name is the lowercase version of the constant (thus class Fred is assumed to be in file fred.rb). If found, it returns the loaded class. It therefore implements an autoload feature similar to Kernel#autoload and Module#autoload.

def Object.const_missing(name)
  @looked_for ||= {}
  str_name = name.to_s
  raise "Class not found: #{name}" if @looked_for[str_name]
  @looked_for[str_name] = 1
  file = str_name.downcase
  require file
  klass = const_get(name)
  return klass if klass
  raise "Class not found: #{name}"
end

Defines the constants of OLE Automation server as mod’s constants. The first argument is WIN32OLE object or type library name. If 2nd argument is omitted, the default is WIN32OLE. The first letter of Ruby’s constant variable name is upper case, so constant variable name of WIN32OLE object is capitalized. For example, the ‘xlTop’ constant of Excel is changed to ‘XlTop’ in WIN32OLE. If the first letter of constant variable is not [A-Z], then the constant is defined as CONSTANTS hash element.

module EXCEL_CONST
end
excel = WIN32OLE.new('Excel.Application')
WIN32OLE.const_load(excel, EXCEL_CONST)
puts EXCEL_CONST::XlTop # => -4160
puts EXCEL_CONST::CONSTANTS['_xlDialogChartSourceData'] # => 541

WIN32OLE.const_load(excel)
puts WIN32OLE::XlTop # => -4160

module MSO
end
WIN32OLE.const_load('Microsoft Office 9.0 Object Library', MSO)
puts MSO::MsoLineSingle # => 1

Returns whether or not the constant const is defined.

See also have_const