Results for: "Array"

Returns true if the given class variable is defined in obj. String arguments are converted to symbols.

class Fred
  @@foo = 99
end
Fred.class_variable_defined?(:@@foo)    #=> true
Fred.class_variable_defined?(:@@bar)    #=> false

Makes hsh compare its keys by their identity, i.e. it will consider exact same objects as same keys.

h1 = { "a" => 100, "b" => 200, :c => "c" }
h1["a"]        #=> 100
h1.compare_by_identity
h1.compare_by_identity? #=> true
h1["a".dup]    #=> nil  # different objects.
h1[:c]         #=> "c"  # same symbols are all same.

Returns true if hsh will compare its keys by their identity. Also see Hash#compare_by_identity.

Raises PStore::Error if the calling code is not in a PStore#transaction or if the code is in a read-only PStore#transaction.

Returns the value of a thread local variable that has been set. Note that these are different than fiber local values. For fiber local values, please see Thread#[] and Thread#[]=.

Thread local values are carried along with threads, and do not respect fibers. For example:

Thread.new {
  Thread.current.thread_variable_set("foo", "bar") # set a thread local
  Thread.current["foo"] = "bar"                    # set a fiber local

  Fiber.new {
    Fiber.yield [
      Thread.current.thread_variable_get("foo"), # get the thread local
      Thread.current["foo"],                     # get the fiber local
    ]
  }.resume
}.join.value # => ['bar', nil]

The value “bar” is returned for the thread local, where nil is returned for the fiber local. The fiber is executed in the same thread, so the thread local values are available.

Sets a thread local with key to value. Note that these are local to threads, and not to fibers. Please see Thread#thread_variable_get and Thread#[] for more information.

Establishes proc on thr as the handler for tracing, or disables tracing if the parameter is nil.

See Kernel#set_trace_func.

Adds proc as a handler for tracing.

See Thread#set_trace_func and Kernel#set_trace_func.

Returns the value of the local variable symbol.

def foo
  a = 1
  binding.local_variable_get(:a) #=> 1
  binding.local_variable_get(:b) #=> NameError
end

This method is the short version of the following code:

binding.eval("#{symbol}")

Set local variable named symbol as obj.

def foo
  a = 1
  bind = binding
  bind.local_variable_set(:a, 2) # set existing local variable `a'
  bind.local_variable_set(:b, 3) # create new local variable `b'
                                 # `b' exists only in binding

  p bind.local_variable_get(:a)  #=> 2
  p bind.local_variable_get(:b)  #=> 3
  p a                            #=> 2
  p b                            #=> NameError
end

This method behaves similarly to the following code:

binding.eval("#{symbol} = #{obj}")

if obj can be dumped in Ruby code.

Returns true if a local variable symbol exists.

def foo
  a = 1
  binding.local_variable_defined?(:a) #=> true
  binding.local_variable_defined?(:b) #=> false
end

This method is the short version of the following code:

binding.eval("defined?(#{symbol}) == 'local-variable'")

Establishes proc as the handler for tracing, or disables tracing if the parameter is nil.

Note: this method is obsolete, please use TracePoint instead.

proc takes up to six parameters:

• an event name

• a filename

• a line number

• an object id

• a binding

• the name of a class

proc is invoked whenever an event occurs.

Events are:

c-call

call a C-language routine

c-return

return from a C-language routine

call

call a Ruby method

class

start a class or module definition),

end

finish a class or module definition),

line

execute code on a new line

raise

raise an exception

return

return from a Ruby method

Tracing is disabled within the context of proc.

  class Test
  def test
    a = 1
    b = 2
  end
  end

  set_trace_func proc { |event, file, line, id, binding, classname|
     printf "%8s %s:%-2d %10s %8s\n", event, file, line, id, classname
  }
  t = Test.new
  t.test

    line prog.rb:11               false
  c-call prog.rb:11        new    Class
  c-call prog.rb:11 initialize   Object
c-return prog.rb:11 initialize   Object
c-return prog.rb:11        new    Class
    line prog.rb:12               false
    call prog.rb:2        test     Test
    line prog.rb:3        test     Test
    line prog.rb:4        test     Test
  return prog.rb:4        test     Test

Returns the last win32 Error of the current executing Thread or nil if none

Sets the last win32 Error of the current executing Thread to error

Starts tracing object allocations from the ObjectSpace extension module.

For example:

require 'objspace'

class C
  include ObjectSpace

  def foo
    trace_object_allocations do
      obj = Object.new
      p "#{allocation_sourcefile(obj)}:#{allocation_sourceline(obj)}"
    end
  end
end

C.new.foo #=> "objtrace.rb:8"

This example has included the ObjectSpace module to make it easier to read, but you can also use the ::trace_object_allocations notation (recommended).

Note that this feature introduces a huge performance decrease and huge memory consumption.

Clear default gem related variables. It is for test

Generates a private and public key unless a private key already exists. If this DH instance was generated from public DH parameters (e.g. by encoding the result of DH#public_key), then this method needs to be called first in order to generate the per-session keys before performing the actual key exchange.

Example

dh = OpenSSL::PKey::DH.new(2048)
public_key = dh.public_key #contains no private/public key yet
public_key.generate_key!
puts public_key.private? # => true

See the OpenSSL documentation for EC_KEY_generate_key()