Results for: "slice"

Defines a named attribute for this module, where the name is symbol.id2name, creating an instance variable (@name) and a corresponding access method to read it. Also creates a method called name= to set the attribute. String arguments are converted to symbols. Returns an array of defined method names as symbols.

module Mod
  attr_accessor(:one, :two) #=> [:one, :one=, :two, :two=]
end
Mod.instance_methods.sort   #=> [:one, :one=, :two, :two=]

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]

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!

Makes new_name a new copy of the method old_name. This can be used to retain access to methods that are overridden.

module Mod
  alias_method :orig_exit, :exit #=> :orig_exit
  def exit(code=0)
    puts "Exiting with code #{code}"
    orig_exit(code)
  end
end
include Mod
exit(99)

produces:

Exiting with code 99

Execute the provided block, but preserve the precision limit

BigDecimal.limit(100)
puts BigDecimal.limit
BigDecimal.save_limit do
    BigDecimal.limit(200)
    puts BigDecimal.limit
end
puts BigDecimal.limit

Returns the number of decimal significant digits in self.

BigDecimal("0").n_significant_digits         # => 0
BigDecimal("1").n_significant_digits         # => 1
BigDecimal("1.1").n_significant_digits       # => 2
BigDecimal("3.1415").n_significant_digits    # => 5
BigDecimal("-1e20").n_significant_digits     # => 1
BigDecimal("1e-20").n_significant_digits     # => 1
BigDecimal("Infinity").n_significant_digits  # => 0
BigDecimal("-Infinity").n_significant_digits # => 0
BigDecimal("NaN").n_significant_digits       # => 0

Return the accept character set for all new CGI instances.

Set the accept character set for all new CGI instances.

Implemented for compatibility; returns true unless jd is invalid (i.e., not a Numeric).

Date.valid_jd?(2451944) # => true

See argument start.

Related: Date.jd.

Returns true if the arguments define a valid ordinal date, false otherwise:

Date.valid_ordinal?(2001, 34)  # => true
Date.valid_ordinal?(2001, 366) # => false

See argument start.

Related: Date.jd, Date.ordinal.

Returns true if the arguments define a valid ordinal date, false otherwise:

Date.valid_date?(2001, 2, 3)  # => true
Date.valid_date?(2001, 2, 29) # => false
Date.valid_date?(2001, 2, -1) # => true

See argument start.

Date.valid_date? is an alias for Date.valid_civil?.

Related: Date.jd, Date.new.

Returns true if the arguments define a valid ordinal date, false otherwise:

Date.valid_date?(2001, 2, 3)  # => true
Date.valid_date?(2001, 2, 29) # => false
Date.valid_date?(2001, 2, -1) # => true

See argument start.

Date.valid_date? is an alias for Date.valid_civil?.

Related: Date.jd, Date.new.

Returns true if the arguments define a valid commercial date, false otherwise:

Date.valid_commercial?(2001, 5, 6) # => true
Date.valid_commercial?(2001, 5, 8) # => false

See Date.commercial.

See argument start.

Related: Date.jd, Date.commercial.

Returns true if the given year is a leap year in the proleptic Julian calendar, false otherwise:

Date.julian_leap?(1900) # => true
Date.julian_leap?(1901) # => false

Related: Date.gregorian_leap?.

Calls the block with each remaining line read from the stream; returns self. Does nothing if already at end-of-stream; See Line IO.

With no arguments given, reads lines as determined by line separator $/:

f = File.new('t.txt')
f.each_line {|line| p line }
f.each_line {|line| fail 'Cannot happen' }
f.close

Output:

"First line\n"
"Second line\n"
"\n"
"Fourth line\n"
"Fifth line\n"

With only string argument sep given, reads lines as determined by line separator sep; see Line Separator:

f = File.new('t.txt')
f.each_line('li') {|line| p line }
f.close

Output:

"First li"
"ne\nSecond li"
"ne\n\nFourth li"
"ne\nFifth li"
"ne\n"

The two special values for sep are honored:

f = File.new('t.txt')
# Get all into one string.
f.each_line(nil) {|line| p line }
f.close

Output:

"First line\nSecond line\n\nFourth line\nFifth line\n"

f.rewind
# Get paragraphs (up to two line separators).
f.each_line('') {|line| p line }

Output:

"First line\nSecond line\n\n"
"Fourth line\nFifth line\n"

With only integer argument limit given, limits the number of bytes in each line; see Line Limit:

f = File.new('t.txt')
f.each_line(8) {|line| p line }
f.close

Output:

"First li"
"ne\n"
"Second l"
"ine\n"
"\n"
"Fourth l"
"ine\n"
"Fifth li"
"ne\n"

With arguments sep and limit given, combines the two behaviors:

• Calls with the next line as determined by line separator sep.

• But returns no more bytes than are allowed by the limit.

Optional keyword argument chomp specifies whether line separators are to be omitted:

f = File.new('t.txt')
f.each_line(chomp: true) {|line| p line }
f.close

Output:

"First line"
"Second line"
""
"Fourth line"
"Fifth line"

Returns an Enumerator if no block is given.

IO#each is an alias for IO#each_line.

Returns true if matching against re can be done in linear time to the input string.

Regexp.linear_time?(/re/) # => true

Note that this is a property of the ruby interpreter, not of the argument regular expression. Identical regexp can or cannot run in linear time depending on your ruby binary. Neither forward nor backward compatibility is guaranteed about the return value of this method. Our current algorithm is (*1) but this is subject to change in the future. Alternative implementations can also behave differently. They might always return false for everything.

(*1): doi.org/10.1109/SP40001.2021.00032

Dup internal hash.

Clone internal hash.

Iterates over each line in the file and yields a String object for each.

Creates a hard link at pathname.

See File.link.

Creates a symbolic link.

See File.symlink.

Accepts an incoming connection using accept(2) after O_NONBLOCK is set for the underlying file descriptor. It returns an array containing the accepted socket for the incoming connection, client_socket, and an Addrinfo, client_addrinfo.

Example

# In one script, start this first
require 'socket'
include Socket::Constants
socket = Socket.new(AF_INET, SOCK_STREAM, 0)
sockaddr = Socket.sockaddr_in(2200, 'localhost')
socket.bind(sockaddr)
socket.listen(5)
begin # emulate blocking accept
  client_socket, client_addrinfo = socket.accept_nonblock
rescue IO::WaitReadable, Errno::EINTR
  IO.select([socket])
  retry
end
puts "The client said, '#{client_socket.readline.chomp}'"
client_socket.puts "Hello from script one!"
socket.close

# In another script, start this second
require 'socket'
include Socket::Constants
socket = Socket.new(AF_INET, SOCK_STREAM, 0)
sockaddr = Socket.sockaddr_in(2200, 'localhost')
socket.connect(sockaddr)
socket.puts "Hello from script 2."
puts "The server said, '#{socket.readline.chomp}'"
socket.close

Refer to Socket#accept for the exceptions that may be thrown if the call to accept_nonblock fails.

Socket#accept_nonblock may raise any error corresponding to accept(2) failure, including Errno::EWOULDBLOCK.

If the exception is Errno::EWOULDBLOCK, Errno::EAGAIN, Errno::ECONNABORTED or Errno::EPROTO, it is extended by IO::WaitReadable. So IO::WaitReadable can be used to rescue the exceptions for retrying accept_nonblock.

By specifying a keyword argument exception to false, you can indicate that accept_nonblock should not raise an IO::WaitReadable exception, but return the symbol :wait_readable instead.

See

• Socket#accept

yield socket and client address for each a connection accepted via given sockets.

The arguments are a list of sockets. The individual argument should be a socket or an array of sockets.

This method yields the block sequentially. It means that the next connection is not accepted until the block returns. So concurrent mechanism, thread for example, should be used to service multiple clients at a time.