Iterates over strongly connected components in a graph. The graph is represented by node and each_child.
node is the first node. each_child should have call
method which takes a node argument and yields for each child node.
Return value is unspecified.
TSort.each_strongly_connected_component_from is a class method and it doesn’t need a class to represent a graph which includes TSort
.
graph = {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]} each_child = lambda {|n, &b| graph[n].each(&b) } TSort.each_strongly_connected_component_from(1, each_child) {|scc| p scc } #=> [4] # [2, 3] # [1]
Returns the new Array suitable for pattern matching containing the values of the row.
Set
the default id conversion object.
This is expected to be an instance such as DRb::DRbIdConv
that responds to to_id
and to_obj
that can convert objects to and from DRb
references.
See DRbServer#default_id_conv.
Set
the default id conversion object.
This is expected to be an instance such as DRb::DRbIdConv
that responds to to_id
and to_obj
that can convert objects to and from DRb
references.
See DRbServer#default_id_conv.
Returns the fractional part of the second.
DateTime.new(2001,2,3,4,5,6.5).sec_fraction #=> (1/2)
Requests a connection to be made on the given remote_sockaddr
after O_NONBLOCK is set for the underlying file descriptor. Returns 0 if successful, otherwise an exception is raised.
# +remote_sockaddr+ - the +struct+ sockaddr contained in a string or Addrinfo object
# Pull down Google's web page require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(80, 'www.google.com') begin # emulate blocking connect socket.connect_nonblock(sockaddr) rescue IO::WaitWritable IO.select(nil, [socket]) # wait 3-way handshake completion begin socket.connect_nonblock(sockaddr) # check connection failure rescue Errno::EISCONN end end socket.write("GET / HTTP/1.0\r\n\r\n") results = socket.read
Refer to Socket#connect
for the exceptions that may be thrown if the call to connect_nonblock fails.
Socket#connect_nonblock
may raise any error corresponding to connect(2) failure, including Errno::EINPROGRESS.
If the exception is Errno::EINPROGRESS, it is extended by IO::WaitWritable
. So IO::WaitWritable
can be used to rescue the exceptions for retrying connect_nonblock.
By specifying a keyword argument exception to false
, you can indicate that connect_nonblock
should not raise an IO::WaitWritable
exception, but return the symbol :wait_writable
instead.
# Socket#connect
Compiled instruction sequence represented by a RubyVM::InstructionSequence
instance on the :script_compiled
event.
Note that this method is MRI specific.
Returns an array of flattened objects returned by the block.
With a block given, calls the block with successive elements; returns a flattened array of objects returned by the block:
[0, 1, 2, 3].flat_map {|element| -element } # => [0, -1, -2, -3] [0, 1, 2, 3].flat_map {|element| [element, -element] } # => [0, 0, 1, -1, 2, -2, 3, -3] [[0, 1], [2, 3]].flat_map {|e| e + [100] } # => [0, 1, 100, 2, 3, 100] {foo: 0, bar: 1, baz: 2}.flat_map {|key, value| [key, value] } # => [:foo, 0, :bar, 1, :baz, 2]
With no block given, returns an Enumerator.
Alias: collect_concat
.
Calls the block with each successive overlapped n
-tuple of elements; returns self
:
a = [] (1..5).each_cons(3) {|element| a.push(element) } a # => [[1, 2, 3], [2, 3, 4], [3, 4, 5]] a = [] h = {foo: 0, bar: 1, baz: 2, bam: 3} h.each_cons(2) {|element| a.push(element) } a # => [[[:foo, 0], [:bar, 1]], [[:bar, 1], [:baz, 2]], [[:baz, 2], [:bam, 3]]]
With no block given, returns an Enumerator
.
Adds a post-install hook that will be passed an Gem::Installer
instance when Gem::Installer#install
is called
Adds a post-installs hook that will be passed a Gem::DependencyInstaller
and a list of installed specifications when Gem::DependencyInstaller#install
is complete
Adds a post-uninstall hook that will be passed a Gem::Uninstaller
instance and the spec that was uninstalled when Gem::Uninstaller#uninstall
is called
Returns the new Hash suitable for pattern matching containing only the keys specified as an argument.
Extensions to build when installing the gem, specifically the paths to extconf.rb-style files used to compile extensions.
These files will be run when the gem is installed, causing the C (or whatever) code to be compiled on the user’s machine.
Usage:
spec.extensions << 'ext/rmagic/extconf.rb'
See Gem::Ext::Builder
for information about writing extensions for gems.
Sets extensions to extensions
, ensuring it is an array.
Returns extensions.
Setter for extensions val
.
Adds to array
all elements from each Array in other_arrays
; returns self
:
a = [0, 1] a.concat([2, 3], [4, 5]) # => [0, 1, 2, 3, 4, 5]
Calls the block, if given, with combinations of elements of self
; returns self
. The order of combinations is indeterminate.
When a block and an in-range positive Integer argument n
(0 < n <= self.size
) are given, calls the block with all n
-tuple combinations of self
.
Example:
a = [0, 1, 2] a.combination(2) {|combination| p combination }
Output:
[0, 1] [0, 2] [1, 2]
Another example:
a = [0, 1, 2] a.combination(3) {|combination| p combination }
Output:
[0, 1, 2]
When n
is zero, calls the block once with a new empty Array:
a = [0, 1, 2] a1 = a.combination(0) {|combination| p combination }
Output:
[]
When n
is out of range (negative or larger than self.size
), does not call the block:
a = [0, 1, 2] a.combination(-1) {|combination| fail 'Cannot happen' } a.combination(4) {|combination| fail 'Cannot happen' }
Returns a new Enumerator if no block given:
a = [0, 1, 2] a.combination(2) # => #<Enumerator: [0, 1, 2]:combination(2)>