Returns a new Array containing those elements from self
that are not duplicates, the first occurrence always being retained.
With no block given, identifies and omits duplicates using method eql?
to compare.
a = [0, 0, 1, 1, 2, 2] a.uniq # => [0, 1, 2]
With a block given, calls the block for each element; identifies (using method eql?
) and omits duplicate values, that is, those elements for which the block returns the same value:
a = ['a', 'aa', 'aaa', 'b', 'bb', 'bbb'] a.uniq {|element| element.size } # => ["a", "aa", "aaa"]
With no block, returns a new array containing only unique elements; the array has no two elements e0
and e1
such that e0.eql?(e1)
:
%w[a b c c b a a b c].uniq # => ["a", "b", "c"] [0, 1, 2, 2, 1, 0, 0, 1, 2].uniq # => [0, 1, 2]
With a block, returns a new array containing only for which the block returns a unique value:
a = [0, 1, 2, 3, 4, 5, 5, 4, 3, 2, 1] a.uniq {|i| i.even? ? i : 0 } # => [0, 2, 4] a = %w[a b c d e e d c b a a b c d e] a.uniq {|c| c < 'c' } # => ["a", "c"]
Like Enumerable#uniq
, but chains operation to be lazy-evaluated.
Like Enumerable#uniq
, but chains operation to be lazy-evaluated.
UNIXServer
represents a UNIX domain stream server socket.
UNIXSocket
represents a UNIX domain stream client socket.
Ruby supports two forms of objectified methods. Class
Method
is used to represent methods that are associated with a particular object: these method objects are bound to that object. Bound method objects for an object can be created using Object#method
.
Ruby also supports unbound methods; methods objects that are not associated with a particular object. These can be created either by calling Module#instance_method
or by calling unbind on a bound method object. The result of both of these is an UnboundMethod
object.
Unbound methods can only be called after they are bound to an object. That object must be a kind_of? the method’s original class.
class Square def area @side * @side end def initialize(side) @side = side end end area_un = Square.instance_method(:area) s = Square.new(12) area = area_un.bind(s) area.call #=> 144
Unbound methods are a reference to the method at the time it was objectified: subsequent changes to the underlying class will not affect the unbound method.
class Test def test :original end end um = Test.instance_method(:test) class Test def test :modified end end t = Test.new t.test #=> :modified um.bind(t).call #=> :original
define UnicodeNormalize
module here so that we don’t have to look it up
A base class for objects representing a C union
A pointer to a C union
This exception is raised if the required unicode support is missing on the system. Usually this means that the iconv library is not installed.
Implements DRb
over a UNIX socket
DRb
UNIX socket URIs look like drbunix:<path>?<option>
. The option is optional.
Raised when removing a gem with the uninstall command fails
An Uninstaller
.
The uninstaller fires pre and post uninstall hooks. Hooks can be added either through a rubygems_plugin.rb file in an installed gem or via a rubygems/defaults/#{RUBY_ENGINE}.rb or rubygems/defaults/operating_system.rb file. See Gem.pre_uninstall
and Gem.post_uninstall
for details.
Helper methods for both Gem::Installer
and Gem::Uninstaller
The class of the singleton object nil
.
A generic error class raised when an invalid operation is attempted. Kernel#raise
will raise a RuntimeError
if no Exception
class is specified.
raise "ouch"
raises the exception:
RuntimeError: ouch
Use the Monitor
class when you want to have a lock object for blocks with mutual exclusion.
require 'monitor' lock = Monitor.new lock.synchronize do # exclusive access end
Raised when OLE processing failed.
EX:
obj = WIN32OLE.new("NonExistProgID")
raises the exception:
WIN32OLERuntimeError: unknown OLE server: `NonExistProgID' HRESULT error code:0x800401f3 Invalid class string
Raised when throw
is called with a tag which does not have corresponding catch
block.
throw "foo", "bar"
raises the exception:
UncaughtThrowError: uncaught throw "foo"
The Warning
module contains a single method named warn
, and the module extends itself, making Warning.warn
available. Warning.warn
is called for all warnings issued by Ruby. By default, warnings are printed to $stderr.
Changing the behavior of Warning.warn
is useful to customize how warnings are handled by Ruby, for instance by filtering some warnings, and/or outputting warnings somewhere other than $stderr.
If you want to change the behavior of Warning.warn
you should use +Warning.extend(MyNewModuleWithWarnMethod)+ and you can use ‘super` to get the default behavior of printing the warning to $stderr.
Example:
module MyWarningFilter def warn(message, category: nil, **kwargs) if /some warning I want to ignore/.match?(message) # ignore else super end end end Warning.extend MyWarningFilter
You should never redefine Warning#warn
(the instance method), as that will then no longer provide a way to use the default behavior.
The warning
gem provides convenient ways to customize Warning.warn
.
A representation of a C function
@libc = Fiddle.dlopen "/lib/libc.so.6" #=> #<Fiddle::Handle:0x00000001d7a8d8> f = Fiddle::Function.new( @libc['strcpy'], [Fiddle::TYPE_VOIDP, Fiddle::TYPE_VOIDP], Fiddle::TYPE_VOIDP) #=> #<Fiddle::Function:0x00000001d8ee00> buff = "000" #=> "000" str = f.call(buff, "123") #=> #<Fiddle::Pointer:0x00000001d0c380 ptr=0x000000018a21b8 size=0 free=0x00000000000000> str.to_s => "123"
@libc = Fiddle.dlopen "/lib/libc.so.6" #=> #<Fiddle::Handle:0x00000001d7a8d8> f = Fiddle::Function.new(@libc['strcpy'], [TYPE_VOIDP, TYPE_VOIDP], TYPE_VOIDP) #=> #<Fiddle::Function:0x00000001d8ee00> f.abi == Fiddle::Function::DEFAULT #=> true