Results for: "OptionParser"

Sets whether or not to ignore case on completion.

Returns true if completion ignores case. If no, returns false.

NOTE: Returns the same object that is specified by Readline.completion_case_fold= method.

require "readline"

Readline.completion_case_fold = "This is a String."
p Readline.completion_case_fold # => "This is a String."

Sets a list of characters which can be used to quote a substring of the line. Completion occurs on the entire substring, and within the substring Readline.completer_word_break_characters are treated as any other character, unless they also appear within this list.

Raises NotImplementedError if the using readline library does not support.

Gets a list of characters which can be used to quote a substring of the line.

Raises NotImplementedError if the using readline library does not support.

The file name and line number of the caller of the caller of this method.

depth is how many layers up the call stack it should go.

e.g.,

def a; Gem.location_of_caller; end a #=> [“x.rb”, 2] # (it’ll vary depending on file name and line number)

def b; c; end def c; Gem.location_of_caller(2); end b #=> [“x.rb”, 6] # (it’ll vary depending on file name and line number)

Returns a String containing the API compatibility version of Ruby

Returns the latest release version of RubyGems.

Returns the version of the latest release-version of gem name

User Code Block

Comes from ripper, called on every parse error, msg is a string

Get a single optional argument from the command line. If more than one argument is given, return only the first. Return nil if none are given.

Iterates backwards over array elements.

When a block given, passes, in reverse order, each element to the block; returns self:

a = [:foo, 'bar', 2]
a.reverse_each {|element|  puts "#{element.class} #{element}" }

Output:

Integer 2
String bar
Symbol foo

Allows the array to be modified during iteration:

a = [:foo, 'bar', 2]
a.reverse_each {|element| puts element; a.clear if element.to_s.start_with?('b') }

Output:

2
bar

When no block given, returns a new Enumerator:

a = [:foo, 'bar', 2]
e = a.reverse_each
e # => #<Enumerator: [:foo, "bar", 2]:reverse_each>
a1 = e.each {|element|  puts "#{element.class} #{element}" }

Output:

Integer 2
String bar
Symbol foo

Related: each, each_index.

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]]

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

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().

Creates module functions for the named methods. These functions may be called with the module as a receiver, and also become available as instance methods to classes that mix in the module. Module functions are copies of the original, and so may be changed independently. The instance-method versions are made private. If used with no arguments, subsequently defined methods become module functions. String arguments are converted to symbols. If a single argument is passed, it is returned. If no argument is passed, nil is returned. If multiple arguments are passed, the arguments are returned as an array.

module Mod
  def one
    "This is one"
  end
  module_function :one
end
class Cls
  include Mod
  def call_one
    one
  end
end
Mod.one     #=> "This is one"
c = Cls.new
c.call_one  #=> "This is one"
module Mod
  def one
    "This is the new one"
  end
end
Mod.one     #=> "This is one"
c.call_one  #=> "This is the new one"

Returns the fractional part of the day in range (Rational(0, 1)…Rational(1, 1)):

DateTime.new(2001,2,3,12).day_fraction # => (1/2)

Returns true if the set is a proper subset of the given set.

The block need not return a String object:

csv = CSV.open(path, headers: true)
csv.header_convert {|header, field_info| header.to_sym }
table = csv.read
table.headers # => [:Name, :Value]

If converter_name is given, the block is not called:

csv = CSV.open(path, headers: true)
csv.header_convert(:downcase) {|header, field_info| fail 'Cannot happen' }
table = csv.read
table.headers # => ["name", "value"]

Raises a parse-time exception if converter_name is not the name of a built-in field converter:

csv = CSV.open(path, headers: true)
csv.header_convert(:nosuch)
# Raises NoMethodError (undefined method `arity' for nil:NilClass)
csv.read

Returns the Ruby source filename and line number of the binding object.