Temporarily turn off warnings. Intended for tests only.
Temporarily turn off warnings. Intended for tests only.
Default description for the gem install and update commands.
The iterator version of the strongly_connected_components
method. obj.each_strongly_connected_component
is similar to obj.strongly_connected_components.each
, but modification of obj during the iteration may lead to unexpected results.
each_strongly_connected_component
returns nil
.
class G include TSort def initialize(g) @g = g end def tsort_each_child(n, &b) @g[n].each(&b) end def tsort_each_node(&b) @g.each_key(&b) end end graph = G.new({1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]}) graph.each_strongly_connected_component {|scc| p scc } #=> [4] # [2] # [3] # [1] graph = G.new({1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}) graph.each_strongly_connected_component {|scc| p scc } #=> [4] # [2, 3] # [1]
The iterator version of the TSort.strongly_connected_components
method.
The graph is represented by each_node and each_child. each_node should have call
method which yields for each node in the graph. each_child should have call
method which takes a node argument and yields for each child node.
g = {1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]} each_node = lambda {|&b| g.each_key(&b) } each_child = lambda {|n, &b| g[n].each(&b) } TSort.each_strongly_connected_component(each_node, each_child) {|scc| p scc } #=> [4] # [2] # [3] # [1] g = {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]} each_node = lambda {|&b| g.each_key(&b) } each_child = lambda {|n, &b| g[n].each(&b) } TSort.each_strongly_connected_component(each_node, each_child) {|scc| p scc } #=> [4] # [2, 3] # [1]
If the ordering field is missing, or if the ordering field is present and set to false, then the genTime field only indicates the time at which the time-stamp token has been created by the TSA. In such a case, the ordering of time-stamp tokens issued by the same TSA or different TSAs is only possible when the difference between the genTime of the first time-stamp token and the genTime of the second time-stamp token is greater than the sum of the accuracies of the genTime for each time-stamp token.
If the ordering field is present and set to true, every time-stamp token from the same TSA can always be ordered based on the genTime field, regardless of the genTime accuracy.
Returns the index of a specified element.
When argument object
is given but no block, returns the index of the first element element
for which object == element
:
a = [:foo, 'bar', 2, 'bar'] a.index('bar') # => 1
Returns nil
if no such element found.
When both argument object
and a block are given, calls the block with each successive element; returns the index of the first element for which the block returns a truthy value:
a = [:foo, 'bar', 2, 'bar'] a.index {|element| element == 'bar' } # => 1
Returns nil
if the block never returns a truthy value.
When neither an argument nor a block is given, returns a new Enumerator:
a = [:foo, 'bar', 2] e = a.index e # => #<Enumerator: [:foo, "bar", 2]:index> e.each {|element| element == 'bar' } # => 1
Array#find_index
is an alias for Array#index
.
Related: rindex
.
Returns the singleton class of obj. This method creates a new singleton class if obj does not have one.
If obj is nil
, true
, or false
, it returns NilClass
, TrueClass
, or FalseClass
, respectively. If obj is an Integer
, a Float
or a Symbol
, it raises a TypeError
.
Object.new.singleton_class #=> #<Class:#<Object:0xb7ce1e24>> String.singleton_class #=> #<Class:String> nil.singleton_class #=> NilClass
Returns an array of the names of singleton methods for obj. If the optional all parameter is true, the list will include methods in modules included in obj. Only public and protected singleton methods are returned.
module Other def three() end end class Single def Single.four() end end a = Single.new def a.one() end class << a include Other def two() end end Single.singleton_methods #=> [:four] a.singleton_methods(false) #=> [:two, :one] a.singleton_methods #=> [:two, :one, :three]
Returns true
if obj is an instance of the given class. See also Object#kind_of?
.
class A; end class B < A; end class C < B; end b = B.new b.instance_of? A #=> false b.instance_of? B #=> true b.instance_of? C #=> false
Similar to method, searches singleton method only.
class Demo def initialize(n) @iv = n end def hello() "Hello, @iv = #{@iv}" end end k = Demo.new(99) def k.hi "Hi, @iv = #{@iv}" end m = k.singleton_method(:hi) m.call #=> "Hi, @iv = 99" m = k.singleton_method(:hello) #=> NameError
Creates an accessor method to allow assignment to the attribute symbol.id2name
. String
arguments are converted to symbols. Returns an array of defined method names as symbols.
Returns an array containing the names of the public and protected instance methods in the receiver. For a module, these are the public and protected methods; for a class, they are the instance (not singleton) methods. If the optional parameter is false
, the methods of any ancestors are not included.
module A def method1() end end class B include A def method2() end end class C < B def method3() end end A.instance_methods(false) #=> [:method1] B.instance_methods(false) #=> [:method2] B.instance_methods(true).include?(:method1) #=> true C.instance_methods(false) #=> [:method3] C.instance_methods.include?(:method2) #=> true
Note that method visibility changes in the current class, as well as aliases, are considered as methods of the current class by this method:
class C < B alias method4 method2 protected :method2 end C.instance_methods(false).sort #=> [:method2, :method3, :method4]
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
Makes a list of existing constants private.
Returns true
if mod is a singleton class or false
if it is an ordinary class or module.
class C end C.singleton_class? #=> false C.singleton_class.singleton_class? #=> true
Returns an UnboundMethod
representing the given instance method in mod.
class Interpreter def do_a() print "there, "; end def do_d() print "Hello "; end def do_e() print "!\n"; end def do_v() print "Dave"; end Dispatcher = { "a" => instance_method(:do_a), "d" => instance_method(:do_d), "e" => instance_method(:do_e), "v" => instance_method(:do_v) } def interpret(string) string.each_char {|b| Dispatcher[b].bind(self).call } end end interpreter = Interpreter.new interpreter.interpret('dave')
produces:
Hello there, Dave!
Returns a hash of the name/value pairs, to use in pattern matching. Possible keys are: :year
, :month
, :day
, :wday
, :yday
.
Possible usages:
d = Date.new(2022, 10, 5) if d in wday: 3, day: ..7 # uses deconstruct_keys underneath puts "first Wednesday of the month" end #=> prints "first Wednesday of the month" case d in year: ...2022 puts "too old" in month: ..9 puts "quarter 1-3" in wday: 1..5, month: puts "working day in month #{month}" end #=> prints "working day in month 10"
Note that deconstruction by pattern can also be combined with class check:
if d in Date(wday: 3, day: ..7) puts "first Wednesday of the month" end
Returns a hash of the name/value pairs, to use in pattern matching. Possible keys are: :year
, :month
, :day
, :wday
, :yday
, :hour
, :min
, :sec
, :sec_fraction
, :zone
.
Possible usages:
dt = DateTime.new(2022, 10, 5, 13, 30) if d in wday: 1..5, hour: 10..18 # uses deconstruct_keys underneath puts "Working time" end #=> prints "Working time" case dt in year: ...2022 puts "too old" in month: ..9 puts "quarter 1-3" in wday: 1..5, month: puts "working day in month #{month}" end #=> prints "working day in month 10"
Note that deconstruction by pattern can also be combined with class check:
if d in DateTime(wday: 1..5, hour: 10..18, day: ..7) puts "Working time, first week of the month" end
Returns a hash of the name/value pairs, to use in pattern matching. Possible keys are: :year
, :month
, :day
, :yday
, :wday
, :hour
, :min
, :sec
, :subsec
, :dst
, :zone
.
Possible usages:
t = Time.utc(2022, 10, 5, 21, 25, 30) if t in wday: 3, day: ..7 # uses deconstruct_keys underneath puts "first Wednesday of the month" end #=> prints "first Wednesday of the month" case t in year: ...2022 puts "too old" in month: ..9 puts "quarter 1-3" in wday: 1..5, month: puts "working day in month #{month}" end #=> prints "working day in month 10"
Note that deconstruction by pattern can also be combined with class check:
if t in Time(wday: 3, day: ..7) puts "first Wednesday of the month" end
Waits until IO
is priority and returns a truthy value or a falsy value when times out. Priority data is sent and received using the Socket::MSG_OOB flag and is typically limited to streams.
You must require ‘io/wait’ to use this method.
Copies from the given src
to the given dst
, returning the number of bytes copied.
The given src
must be one of the following:
The path to a readable file, from which source data is to be read.
An IO-like object, opened for reading and capable of responding to method :readpartial
or method :read
.
The given dst
must be one of the following:
The path to a writable file, to which data is to be written.
An IO-like object, opened for writing and capable of responding to method :write
.
The examples here use file t.txt
as source:
File.read('t.txt') # => "First line\nSecond line\n\nThird line\nFourth line\n" File.read('t.txt').size # => 47
If only arguments src
and dst
are given, the entire source stream is copied:
# Paths. IO.copy_stream('t.txt', 't.tmp') # => 47 # IOs (recall that a File is also an IO). src_io = File.open('t.txt', 'r') # => #<File:t.txt> dst_io = File.open('t.tmp', 'w') # => #<File:t.tmp> IO.copy_stream(src_io, dst_io) # => 47 src_io.close dst_io.close
With argument src_length
a non-negative integer, no more than that many bytes are copied:
IO.copy_stream('t.txt', 't.tmp', 10) # => 10 File.read('t.tmp') # => "First line"
With argument src_offset
also given, the source stream is read beginning at that offset:
IO.copy_stream('t.txt', 't.tmp', 11, 11) # => 11 IO.read('t.tmp') # => "Second line"