Results for: "minmax"

Returns a two element array which contains the minimum and the maximum value in the enumerable. The first form assumes all objects implement Comparable; the second uses the block to return a <=> b.

a = %w(albatross dog horse)
a.minmax                                  #=> ["albatross", "horse"]
a.minmax { |a, b| a.length <=> b.length } #=> ["dog", "albatross"]

Returns a two element array containing the objects in enum that correspond to the minimum and maximum values respectively from the given block.

If no block is given, an enumerator is returned instead.

a = %w(albatross dog horse)
a.minmax_by { |x| x.length }   #=> ["dog", "albatross"]

Sets the minimum and maximum supported protocol versions. See min_version= and max_version=.

Objects of class Binding encapsulate the execution context at some particular place in the code and retain this context for future use. The variables, methods, value of self, and possibly an iterator block that can be accessed in this context are all retained. Binding objects can be created using Kernel#binding, and are made available to the callback of Kernel#set_trace_func.

These binding objects can be passed as the second argument of the Kernel#eval method, establishing an environment for the evaluation.

class Demo
  def initialize(n)
    @secret = n
  end
  def get_binding
    binding
  end
end

k1 = Demo.new(99)
b1 = k1.get_binding
k2 = Demo.new(-3)
b2 = k2.get_binding

eval("@secret", b1)   #=> 99
eval("@secret", b2)   #=> -3
eval("@secret")       #=> nil

Binding objects have no class-specific methods.

Raised when attempting to convert special float values (in particular Infinity or NaN) to numerical classes which don’t support them.

Float::INFINITY.to_r   #=> FloatDomainError: Infinity

mkmf.rb is used by Ruby C extensions to generate a Makefile which will correctly compile and link the C extension to Ruby and a third-party library.

In concurrent programming, a monitor is an object or module intended to be used safely by more than one thread. The defining characteristic of a monitor is that its methods are executed with mutual exclusion. That is, at each point in time, at most one thread may be executing any of its methods. This mutual exclusion greatly simplifies reasoning about the implementation of monitors compared to reasoning about parallel code that updates a data structure.

You can read more about the general principles on the Wikipedia page for Monitors

Examples

Simple object.extend

require 'monitor.rb'

buf = []
buf.extend(MonitorMixin)
empty_cond = buf.new_cond

# consumer
Thread.start do
  loop do
    buf.synchronize do
      empty_cond.wait_while { buf.empty? }
      print buf.shift
    end
  end
end

# producer
while line = ARGF.gets
  buf.synchronize do
    buf.push(line)
    empty_cond.signal
  end
end

The consumer thread waits for the producer thread to push a line to buf while buf.empty?. The producer thread (main thread) reads a line from ARGF and pushes it into buf then calls empty_cond.signal to notify the consumer thread of new data.

Simple Class include

require 'monitor'

class SynchronizedArray < Array

  include MonitorMixin

  def initialize(*args)
    super(*args)
  end

  alias :old_shift :shift
  alias :old_unshift :unshift

  def shift(n=1)
    self.synchronize do
      self.old_shift(n)
    end
  end

  def unshift(item)
    self.synchronize do
      self.old_unshift(item)
    end
  end

  # other methods ...
end

SynchronizedArray implements an Array with synchronized access to items. This Class is implemented as subclass of Array which includes the MonitorMixin module.

Raised when a gem dependencies file specifies a ruby version that does not match the current version.

This exception is raised if the required unicode support is missing on the system. Usually this means that the iconv library is not installed.

Exception raised when there is an invalid encoding detected

A custom InputMethod class used by XMP for evaluating string io.

Map from option/keyword string to object with completion.

Raises when a switch with mandatory argument has no argument.

PrettyPrint::SingleLine is used by PrettyPrint.singleline_format

It is passed to be similar to a PrettyPrint object itself, by responding to:

• text

• breakable

• nest

• group

• flush

• first?

but instead, the output has no line breaks

RingFinger is used by RingServer clients to discover the RingServer’s TupleSpace. Typically, all a client needs to do is call RingFinger.primary to retrieve the remote TupleSpace, which it can then begin using.

To find the first available remote TupleSpace:

Rinda::RingFinger.primary

To create a RingFinger that broadcasts to a custom list:

rf = Rinda::RingFinger.new  ['localhost', '192.0.2.1']
rf.primary

Rinda::RingFinger also understands multicast addresses and sets them up properly. This allows you to run multiple RingServers on the same host:

rf = Rinda::RingFinger.new ['239.0.0.1']
rf.primary

You can set the hop count (or TTL) for multicast searches using multicast_hops.

If you use IPv6 multicast you may need to set both an address and the outbound interface index:

rf = Rinda::RingFinger.new ['ff02::1']
rf.multicast_interface = 1
rf.primary

At this time there is no easy way to get an interface index by name.

Since RSS is based on XML, it must have opening and closing tags that match. If they don’t, a MissingTagError will be raised.

Certain attributes are required on specific tags in an RSS feed. If a feed is missing one of these attributes, a MissingAttributeError is raised.

The command manager registers and installs all the individual sub-commands supported by the gem command.

Extra commands can be provided by writing a rubygems_plugin.rb file in an installed gem. You should register your command against the Gem::CommandManager instance, like this:

# file rubygems_plugin.rb
require 'rubygems/command_manager'

Gem::CommandManager.instance.register_command :edit

You should put the implementation of your command in rubygems/commands.

# file rubygems/commands/edit_command.rb
class Gem::Commands::EditCommand < Gem::Command
  # ...
end

See Gem::Command for instructions on writing gem commands.

Raised when trying to activate a gem, and that gem does not exist on the system. Instead of rescuing from this class, make sure to rescue from the superclass Gem::LoadError to catch all types of load errors.

Raised when trying to activate a gem, and the gem exists on the system, but not the requested version. Instead of rescuing from this class, make sure to rescue from the superclass Gem::LoadError to catch all types of load errors.

Generated when trying to lookup a gem to indicate that the gem was found, but that it isn’t usable on the current platform.

fetch and install read these and report them to the user to aid in figuring out why a gem couldn’t be installed.