Synonym for $stdin.
Creates a date object denoting the given ordinal date.
The day of year should be a negative or a positive number (as a relative day from the end of year when negative). It should not be zero.
Date.ordinal(2001) #=> #<Date: 2001-01-01 ...> Date.ordinal(2001,34) #=> #<Date: 2001-02-03 ...> Date.ordinal(2001,-1) #=> #<Date: 2001-12-31 ...>
Creates a DateTime
object denoting the given ordinal date.
DateTime.ordinal(2001,34) #=> #<DateTime: 2001-02-03T00:00:00+00:00 ...> DateTime.ordinal(2001,34,4,5,6,'+7') #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...> DateTime.ordinal(2001,-332,-20,-55,-54,'+7') #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>
Finds and returns an object among nested objects. The nested objects may be instances of various classes. See Dig Methods.
Given symbol or string argument name
, returns the object that is specified by name
and identifiers
:
Foo = Struct.new(:a) f = Foo.new(Foo.new({b: [1, 2, 3]})) f.dig(:a) # => #<struct Foo a={:b=>[1, 2, 3]}> f.dig(:a, :a) # => {:b=>[1, 2, 3]} f.dig(:a, :a, :b) # => [1, 2, 3] f.dig(:a, :a, :b, 0) # => 1 f.dig(:b, 0) # => nil
Given integer argument n
, returns the object that is specified by n
and identifiers
:
f.dig(0) # => #<struct Foo a={:b=>[1, 2, 3]}> f.dig(0, 0) # => {:b=>[1, 2, 3]} f.dig(0, 0, :b) # => [1, 2, 3] f.dig(0, 0, :b, 0) # => 1 f.dig(:b, 0) # => nil
Finds and returns the object in nested objects that is specified by name
and identifiers
. The nested objects may be instances of various classes. See Dig Methods.
Examples:
require "ostruct" address = OpenStruct.new("city" => "Anytown NC", "zip" => 12345) person = OpenStruct.new("name" => "John Smith", "address" => address) person.dig(:address, "zip") # => 12345 person.dig(:business_address, "zip") # => nil
With no argument, returns the first element of self
, if it exists:
(1..4).first # => 1 ('a'..'d').first # => "a"
With non-negative integer argument n
given, returns the first n
elements in an array:
(1..10).first(3) # => [1, 2, 3] (1..10).first(0) # => [] (1..4).first(50) # => [1, 2, 3, 4]
Raises an exception if there is no first element:
(..4).first # Raises RangeError
Returns the Encoding
object that represents the encoding of obj.
Returns true if the set and the given enumerable have no element in common. This method is the opposite of intersect?
.
Set[1, 2, 3].disjoint? Set[3, 4] #=> false Set[1, 2, 3].disjoint? Set[4, 5] #=> true Set[1, 2, 3].disjoint? [3, 4] #=> false Set[1, 2, 3].disjoint? 4..5 #=> true
Divides the set into a set of subsets according to the commonality defined by the given block.
If the arity of the block is 2, elements o1 and o2 are in common if block.call(o1, o2) is true. Otherwise, elements o1 and o2 are in common if block.call(o1) == block.call(o2).
require 'set' numbers = Set[1, 3, 4, 6, 9, 10, 11] set = numbers.divide { |i,j| (i - j).abs == 1 } set #=> #<Set: {#<Set: {1}>, # #<Set: {11, 9, 10}>, # #<Set: {3, 4}>, # #<Set: {6}>}>
Returns an enumerator if no block is given.
Returns the Encoding
object that represents the encoding of sym.
Returns the birth time for the file. If the platform doesn’t have birthtime, raises NotImplementedError
.
See File.birthtime
.
Return encoding of the source.
Creates a pair of sockets connected each other.
domain should be a communications domain such as: :INET, :INET6, :UNIX, etc.
socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.
protocol should be a protocol defined in the domain, defaults to 0 for the domain.
s1, s2 = Socket.pair(:UNIX, :STREAM, 0) s1.send "a", 0 s1.send "b", 0 s1.close p s2.recv(10) #=> "ab" p s2.recv(10) #=> "" p s2.recv(10) #=> "" s1, s2 = Socket.pair(:UNIX, :DGRAM, 0) s1.send "a", 0 s1.send "b", 0 p s2.recv(10) #=> "a" p s2.recv(10) #=> "b"
Creates a pair of sockets connected each other.
domain should be a communications domain such as: :INET, :INET6, :UNIX, etc.
socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.
protocol should be a protocol defined in the domain, defaults to 0 for the domain.
s1, s2 = Socket.pair(:UNIX, :STREAM, 0) s1.send "a", 0 s1.send "b", 0 s1.close p s2.recv(10) #=> "ab" p s2.recv(10) #=> "" p s2.recv(10) #=> "" s1, s2 = Socket.pair(:UNIX, :DGRAM, 0) s1.send "a", 0 s1.send "b", 0 p s2.recv(10) #=> "a" p s2.recv(10) #=> "b"
Creates a pair of sockets connected to each other.
socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.
protocol should be a protocol defined in the domain. 0 is default protocol for the domain.
s1, s2 = UNIXSocket.pair s1.send "a", 0 s1.send "b", 0 p s2.recv(10) #=> "ab"
Creates a pair of sockets connected to each other.
socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.
protocol should be a protocol defined in the domain. 0 is default protocol for the domain.
s1, s2 = UNIXSocket.pair s1.send "a", 0 s1.send "b", 0 p s2.recv(10) #=> "ab"
Returns dispatch ID.
tobj = WIN32OLE_TYPE.new('Microsoft Excel 9.0 Object Library', 'Workbooks') method = WIN32OLE_METHOD.new(tobj, 'Add') puts method.dispid # => 181
Finds and returns the object in nested objects that is specified by key
and identifiers
. The nested objects may be instances of various classes. See Dig Methods.
Nested Hashes:
h = {foo: {bar: {baz: 2}}} h.dig(:foo) # => {:bar=>{:baz=>2}} h.dig(:foo, :bar) # => {:baz=>2} h.dig(:foo, :bar, :baz) # => 2 h.dig(:foo, :bar, :BAZ) # => nil
Nested Hashes and Arrays:
h = {foo: {bar: [:a, :b, :c]}} h.dig(:foo, :bar, 2) # => :c
This method will use the default values for keys that are not present:
h = {foo: {bar: [:a, :b, :c]}} h.dig(:hello) # => nil h.default_proc = -> (hash, _key) { hash } h.dig(:hello, :world) # => h h.dig(:hello, :world, :foo, :bar, 2) # => :c
Opens an IRB session where binding.irb
is called which allows for interactive debugging. You can call any methods or variables available in the current scope, and mutate state if you need to.
Given a Ruby file called potato.rb
containing the following code:
class Potato def initialize @cooked = false binding.irb puts "Cooked potato: #{@cooked}" end end Potato.new
Running ruby potato.rb
will open an IRB session where binding.irb
is called, and you will see the following:
$ ruby potato.rb From: potato.rb @ line 4 : 1: class Potato 2: def initialize 3: @cooked = false => 4: binding.irb 5: puts "Cooked potato: #{@cooked}" 6: end 7: end 8: 9: Potato.new irb(#<Potato:0x00007feea1916670>):001:0>
You can type any valid Ruby code and it will be evaluated in the current context. This allows you to debug without having to run your code repeatedly:
irb(#<Potato:0x00007feea1916670>):001:0> @cooked => false irb(#<Potato:0x00007feea1916670>):002:0> self.class => Potato irb(#<Potato:0x00007feea1916670>):003:0> caller.first => ".../2.5.1/lib/ruby/2.5.0/irb/workspace.rb:85:in `eval'" irb(#<Potato:0x00007feea1916670>):004:0> @cooked = true => true
You can exit the IRB session with the exit
command. Note that exiting will resume execution where binding.irb
had paused it, as you can see from the output printed to standard output in this example:
irb(#<Potato:0x00007feea1916670>):005:0> exit Cooked potato: true
See IRB for more information.
Parses environment variable env
or its uppercase with splitting like a shell.
env
defaults to the basename of the program.
Returns the binding associated with prc.
def fred(param) proc {} end b = fred(99) eval("param", b.binding) #=> 99
Deactivates the trace
Return true if trace was enabled. Return false if trace was disabled.
trace.enabled? #=> true trace.disable #=> true (previous status) trace.enabled? #=> false trace.disable #=> false
If a block is given, the trace will only be disable within the scope of the block.
trace.enabled? #=> true trace.disable do trace.enabled? # only disabled for this block end trace.enabled? #=> true
Note: You cannot access event hooks within the block.
trace.disable { p tp.lineno } #=> RuntimeError: access from outside
Return the generated binding object from event.
Note that for c_call
and c_return
events, the binding returned is the binding of the nearest Ruby method calling the C method, since C methods themselves do not have bindings.