Results for: "module_function"

File#chmod

Changes permission bits on file to the bit pattern represented by mode_int. Actual effects are platform dependent; on Unix systems, see chmod(2) for details. Follows symbolic links. Also see File#lchmod.

f = File.new("out", "w");
f.chmod(0644)   #=> 0

Enumerator::produce

Creates an infinite enumerator from any block, just called over and over. The result of the previous iteration is passed to the next one. If initial is provided, it is passed to the first iteration, and becomes the first element of the enumerator; if it is not provided, the first iteration receives nil, and its result becomes the first element of the iterator.

Raising StopIteration from the block stops an iteration.

Enumerator.produce(1, &:succ)   # => enumerator of 1, 2, 3, 4, ....

Enumerator.produce { rand(10) } # => infinite random number sequence

ancestors = Enumerator.produce(node) { |prev| node = prev.parent or raise StopIteration }
enclosing_section = ancestors.find { |n| n.type == :section }

Using ::produce together with Enumerable methods like Enumerable#detect, Enumerable#slice_after, Enumerable#take_while can provide Enumerator-based alternatives for while and until cycles:

# Find next Tuesday
require "date"
Enumerator.produce(Date.today, &:succ).detect(&:tuesday?)

# Simple lexer:
require "strscan"
scanner = StringScanner.new("7+38/6")
PATTERN = %r{\d+|[-/+*]}
Enumerator.produce { scanner.scan(PATTERN) }.slice_after { scanner.eos? }.first
# => ["7", "+", "38", "/", "6"]

BigDecimal::mode

Returns an integer representing the mode settings for exception handling and rounding.

These modes control exception handling:

Values for setting for exception handling:

You can use method BigDecimal.save_exception_mode to temporarily change, and then automatically restore, exception modes.

For clarity, some examples below begin by setting all exception modes to false.

This mode controls the way rounding is to be performed:

You can use method BigDecimal.save_rounding_mode to temporarily change, and then automatically restore, the rounding mode.

NaNs

Mode BigDecimal::EXCEPTION_NaN controls behavior when a BigDecimal NaN is created.

Settings:

Examples:

BigDecimal.mode(BigDecimal::EXCEPTION_ALL, false) # => 0
BigDecimal('NaN')                                 # => NaN
BigDecimal.mode(BigDecimal::EXCEPTION_NaN, true)  # => 2
BigDecimal('NaN') # Raises FloatDomainError

Infinities

Mode BigDecimal::EXCEPTION_INFINITY controls behavior when a BigDecimal Infinity or -Infinity is created. Settings:

Examples:

BigDecimal.mode(BigDecimal::EXCEPTION_ALL, false)     # => 0
BigDecimal('Infinity')                                # => Infinity
BigDecimal('-Infinity')                               # => -Infinity
BigDecimal.mode(BigDecimal::EXCEPTION_INFINITY, true) # => 1
BigDecimal('Infinity')  # Raises FloatDomainError
BigDecimal('-Infinity') # Raises FloatDomainError

Underflow

Mode BigDecimal::EXCEPTION_UNDERFLOW controls behavior when a BigDecimal underflow occurs. Settings:

Examples:

BigDecimal.mode(BigDecimal::EXCEPTION_ALL, false)      # => 0
def flow_under
  x = BigDecimal('0.1')
  100.times { x *= x }
end
flow_under                                             # => 100
BigDecimal.mode(BigDecimal::EXCEPTION_UNDERFLOW, true) # => 4
flow_under # Raises FloatDomainError

Overflow

Mode BigDecimal::EXCEPTION_OVERFLOW controls behavior when a BigDecimal overflow occurs. Settings:

Examples:

BigDecimal.mode(BigDecimal::EXCEPTION_ALL, false)     # => 0
def flow_over
  x = BigDecimal('10')
  100.times { x *= x }
end
flow_over                                             # => 100
BigDecimal.mode(BigDecimal::EXCEPTION_OVERFLOW, true) # => 1
flow_over # Raises FloatDomainError

Zero Division

Mode BigDecimal::EXCEPTION_ZERODIVIDE controls behavior when a zero-division occurs. Settings:

Examples:

BigDecimal.mode(BigDecimal::EXCEPTION_ALL, false)       # => 0
one = BigDecimal('1')
zero = BigDecimal('0')
one / zero                                              # => Infinity
BigDecimal.mode(BigDecimal::EXCEPTION_ZERODIVIDE, true) # => 16
one / zero # Raises FloatDomainError

All Exceptions

Mode BigDecimal::EXCEPTION_ALL controls all of the above:

BigDecimal.mode(BigDecimal::EXCEPTION_ALL, false) # => 0
BigDecimal.mode(BigDecimal::EXCEPTION_ALL, true)  # => 23

Rounding

Mode BigDecimal::ROUND_MODE controls the way rounding is to be performed; its setting values are:

BigDecimal#divmod

Divides by the specified value, and returns the quotient and modulus as BigDecimal numbers. The quotient is rounded towards negative infinity.

For example:

require 'bigdecimal'

a = BigDecimal("42")
b = BigDecimal("9")

q, m = a.divmod(b)

c = q * b + m

a == c  #=> true

The quotient q is (a/b).floor, and the modulus is the amount that must be added to q * b to get a.

IO#binmode

Sets the stream’s data mode as binary (see Data Mode).

A stream’s data mode may not be changed from binary to text.

IO#binmode?

Returns true if the stream is on binary mode, false otherwise. See Data Mode.

Pathname#chmod

Changes file permissions.

See File.chmod.

Pathname#lchmod

Same as Pathname.chmod, but does not follow symbolic links.

See File.lchmod.

StringIO#binmode

Sets the data mode in self to binary mode; see Data Mode.

ARGF#binmode

Puts ARGF into binary mode. Once a stream is in binary mode, it cannot be reset to non-binary mode. This option has the following effects:

ARGF#binmode?

Returns true if ARGF is being read in binary mode; false otherwise. To enable binary mode use ARGF.binmode.

For example:

ARGF.binmode?  #=> false
ARGF.binmode
ARGF.binmode?  #=> true

CSV#binmode?

No documentation available

Digest::bubblebabble

Returns a BubbleBabble encoded version of a given string.

FileUtils#chmod

Changes permissions on the entries at the paths given in list (a single path or an array of paths) to the permissions given by mode; returns list if it is an array, [list] otherwise:

Argument list or its elements should be interpretable as paths.

Argument mode may be either an integer or a string:

Keyword arguments:

Related: FileUtils.chmod_R.

FileUtils::chmod

Changes permissions on the entries at the paths given in list (a single path or an array of paths) to the permissions given by mode; returns list if it is an array, [list] otherwise:

Argument list or its elements should be interpretable as paths.

Argument mode may be either an integer or a string:

Keyword arguments:

Related: FileUtils.chmod_R.

FileUtils#chmod_R

Like FileUtils.chmod, but changes permissions recursively.

FileUtils::chmod_R

Like FileUtils.chmod, but changes permissions recursively.

Array#repeated_permutation

Calls the block with each repeated permutation of length n of the elements of self; each permutation is an Array; returns self. The order of the permutations is indeterminate.

When a block and a positive Integer argument n are given, calls the block with each n-tuple repeated permutation of the elements of self. The number of permutations is self.size**n.

n = 1:

a = [0, 1, 2]
a.repeated_permutation(1) {|permutation| p permutation }

Output:

[0]
[1]
[2]

n = 2:

a.repeated_permutation(2) {|permutation| p permutation }

Output:

[0, 0]
[0, 1]
[0, 2]
[1, 0]
[1, 1]
[1, 2]
[2, 0]
[2, 1]
[2, 2]

If n is zero, calls the block once with an empty Array.

If n is negative, does not call the block:

a.repeated_permutation(-1) {|permutation| fail 'Cannot happen' }

Returns a new Enumerator if no block given:

a = [0, 1, 2]
a.repeated_permutation(2) # => #<Enumerator: [0, 1, 2]:permutation(2)>

Using Enumerators, it’s convenient to show the permutations and counts for some values of n:

e = a.repeated_permutation(0)
e.size # => 1
e.to_a # => [[]]
e = a.repeated_permutation(1)
e.size # => 3
e.to_a # => [[0], [1], [2]]
e = a.repeated_permutation(2)
e.size # => 9
e.to_a # => [[0, 0], [0, 1], [0, 2], [1, 0], [1, 1], [1, 2], [2, 0], [2, 1], [2, 2]]

Array#repeated_combination

Calls the block with each repeated combination of length n of the elements of self; each combination is an Array; returns self. The order of the combinations is indeterminate.

When a block and a positive Integer argument n are given, calls the block with each n-tuple repeated combination of the elements of self. The number of combinations is (n+1)(n+2)/2.

n = 1:

a = [0, 1, 2]
a.repeated_combination(1) {|combination| p combination }

Output:

[0]
[1]
[2]

n = 2:

a.repeated_combination(2) {|combination| p combination }

Output:

[0, 0]
[0, 1]
[0, 2]
[1, 1]
[1, 2]
[2, 2]

If n is zero, calls the block once with an empty Array.

If n is negative, does not call the block:

a.repeated_combination(-1) {|combination| fail 'Cannot happen' }

Returns a new Enumerator if no block given:

a = [0, 1, 2]
a.repeated_combination(2) # => #<Enumerator: [0, 1, 2]:combination(2)>

Using Enumerators, it’s convenient to show the combinations and counts for some values of n:

e = a.repeated_combination(0)
e.size # => 1
e.to_a # => [[]]
e = a.repeated_combination(1)
e.size # => 3
e.to_a # => [[0], [1], [2]]
e = a.repeated_combination(2)
e.size # => 6
e.to_a # => [[0, 0], [0, 1], [0, 2], [1, 1], [1, 2], [2, 2]]

Fiber#backtrace_locations

Like backtrace, but returns each line of the execution stack as a Thread::Backtrace::Location. Accepts the same arguments as backtrace.

f = Fiber.new { Fiber.yield }
f.resume
loc = f.backtrace_locations.first
loc.label  #=> "yield"
loc.path   #=> "test.rb"
loc.lineno #=> 1

Exception#backtrace_locations

Returns any backtrace associated with the exception. This method is similar to Exception#backtrace, but the backtrace is an array of Thread::Backtrace::Location.

This method is not affected by Exception#set_backtrace().

Socket#connect_nonblock

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.

Parameter 

# +remote_sockaddr+ - the +struct+ sockaddr contained in a string or Addrinfo object

Example: 

# 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.

See 

# Socket#connect

CSV#unconverted_fields?

Returns the value that determines whether unconverted fields are to be available; used for parsing; see {Option unconverted_fields}:

CSV.new('').unconverted_fields? # => nil

CSV#parser_options

No documentation available

CSV#writer_options

No documentation available
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