Convenience method for Shell::CommandProcessor.undef_system_command
Convenience method for Shell::CommandProcessor.install_system_commands. Defines instance methods representing all the executable files found in Shell.default_system_path
, with the given prefix prepended to their names.
Shell.install_system_commands Shell.new.sys_echo("hello") # => hello
Calls block with two arguments, the item and its index, for each item in enum. Given arguments are passed through to each().
If no block is given, an enumerator is returned instead.
hash = Hash.new %w(cat dog wombat).each_with_index { |item, index| hash[item] = index } hash #=> {"cat"=>0, "dog"=>1, "wombat"=>2}
Iterates the given block for each element with an arbitrary object given, and returns the initially given object.
If no block is given, returns an enumerator.
evens = (1..10).each_with_object([]) { |i, a| a << i*2 } #=> [2, 4, 6, 8, 10, 12, 14, 16, 18, 20]
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.
Returns the method identifier for the given object
.
class A include ObjectSpace def foo trace_object_allocations do obj = Object.new p "#{allocation_class_path(obj)}##{allocation_method_id(obj)}" end end end A.new.foo #=> "Class#new"
See ::trace_object_allocations
for more information and examples.
Counts objects for each T_DATA
type.
This method is only for MRI developers interested in performance and memory usage of Ruby programs.
It returns a hash as:
{RubyVM::InstructionSequence=>504, :parser=>5, :barrier=>6, :mutex=>6, Proc=>60, RubyVM::Env=>57, Mutex=>1, Encoding=>99, ThreadGroup=>1, Binding=>1, Thread=>1, RubyVM=>1, :iseq=>1, Random=>1, ARGF.class=>1, Data=>1, :autoload=>3, Time=>2} # T_DATA objects existing at startup on r32276.
If the optional argument, result_hash, is given, it is overwritten and returned. This is intended to avoid probe effect.
The contents of the returned hash is implementation specific and may change in the future.
In this version, keys are Class
object or Symbol
object.
If object is kind of normal (accessible) object, the key is Class
object. If object is not a kind of normal (internal) object, the key is symbol name, registered by rb_data_type_struct.
This method is only expected to work with C Ruby.
Return all reachable objects from ‘obj’.
This method returns all reachable objects from ‘obj’.
If ‘obj’ has two or more references to the same object ‘x’, then returned array only includes one ‘x’ object.
If ‘obj’ is a non-markable (non-heap management) object such as true, false, nil, symbols and Fixnums (and Flonum) then it simply returns nil.
If ‘obj’ has references to an internal object, then it returns instances of ObjectSpace::InternalObjectWrapper
class. This object contains a reference to an internal object and you can check the type of internal object with ‘type’ method.
If ‘obj’ is instance of ObjectSpace::InternalObjectWrapper
class, then this method returns all reachable object from an internal object, which is pointed by ‘obj’.
With this method, you can find memory leaks.
This method is only expected to work except with C Ruby.
Example:
ObjectSpace.reachable_objects_from(['a', 'b', 'c']) #=> [Array, 'a', 'b', 'c'] ObjectSpace.reachable_objects_from(['a', 'a', 'a']) #=> [Array, 'a', 'a', 'a'] # all 'a' strings have different object id ObjectSpace.reachable_objects_from([v = 'a', v, v]) #=> [Array, 'a'] ObjectSpace.reachable_objects_from(1) #=> nil # 1 is not markable (heap managed) object
Specifies Emacs editing mode. The default is this mode. See the manual of GNU Readline
for details of Emacs editing mode.
Raises NotImplementedError
if the using readline library does not support.
Returns true if emacs mode is active. Returns false if not.
Raises NotImplementedError
if the using readline library does not support.
Specifies a character to be appended on completion. Nothing will be appended if an empty string (“”) or nil is specified.
For example:
require "readline" Readline.readline("> ", true) Readline.completion_append_character = " "
Result:
> Input "/var/li". > /var/li Press TAB key. > /var/lib Completes "b" and appends " ". So, you can continuously input "/usr". > /var/lib /usr
NOTE: Only one character can be specified. When “string” is specified, sets only “s” that is the first.
require "readline" Readline.completion_append_character = "string" p Readline.completion_append_character # => "s"
Raises NotImplementedError
if the using readline library does not support.
Returns a string containing a character to be appended on completion. The default is a space (“ ”).
Raises NotImplementedError
if the using readline library does not support.
Sets a list of quote characters which can cause a word break.
Raises NotImplementedError
if the using readline library does not support.
Gets a list of quote characters which can cause a word break.
Raises NotImplementedError
if the using readline library does not support.
Sets a list of characters which can be used to quote a substring of the line. Completion occurs on the entire substring, and within the substring Readline.completer_word_break_characters
are treated as any other character, unless they also appear within this list.
Raises NotImplementedError
if the using readline library does not support.
Gets a list of characters which can be used to quote a substring of the line.
Raises NotImplementedError
if the using readline library does not support.
Sets a list of characters that cause a filename to be quoted by the completer when they appear in a completed filename. The default is nil.
Raises NotImplementedError
if the using readline library does not support.
Gets a list of characters that cause a filename to be quoted by the completer when they appear in a completed filename.
Raises NotImplementedError
if the using readline library does not support.
Returns information about the most recent garbage collection.
Shortcut for defining multiple delegator methods, but with no provision for using a different name. The following two code samples have the same effect:
def_delegators :@records, :size, :<<, :map def_delegator :@records, :size def_delegator :@records, :<< def_delegator :@records, :map
Define method
as delegator instance method with an optional alias name ali
. Method
calls to ali
will be delegated to accessor.method
.
class MyQueue extend Forwardable attr_reader :queue def initialize @queue = [] end def_delegator :@queue, :push, :mypush end q = MyQueue.new q.mypush 42 q.queue #=> [42] q.push 23 #=> NoMethodError
Shortcut for defining multiple delegator methods, but with no provision for using a different name. The following two code samples have the same effect:
def_delegators :@records, :size, :<<, :map def_delegator :@records, :size def_delegator :@records, :<< def_delegator :@records, :map
Defines a method method which delegates to accessor (i.e. it calls the method of the same name in accessor). If new_name is provided, it is used as the name for the delegate method.