Results for: "minmax"

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]]

Array#bsearch_index

Searches self as described at method bsearch, but returns the index of the found element instead of the element itself.

Integer#to_int

Returns self (which is already an Integer).

Refinement#refined_class

Deprecated; prefer target.

Return the class refined by the receiver.

Numeric#to_int

Returns self as an integer; converts using method to_i in the derived class.

Of the Core and Standard Library classes, only Rational and Complex use this implementation.

Examples:

Rational(1, 2).to_int # => 0
Rational(2, 1).to_int # => 2
Complex(2, 0).to_int  # => 2
Complex(2, 1)         # Raises RangeError (non-zero imaginary part)

String#initialize_copy

Replaces the contents of self with the contents of other_string:

s = 'foo'        # => "foo"
s.replace('bar') # => "bar"

String#each_line

With a block given, forms the substrings (“lines”) that are the result of splitting self at each occurrence of the given line separator line_sep; passes each line to the block; returns self:

s = <<~EOT
This is the first line.
This is line two.

This is line four.
This is line five.
EOT

s.each_line {|line| p line }

Output:

"This is the first line.\n"
"This is line two.\n"
"\n"
"This is line four.\n"
"This is line five.\n"

With a different line_sep:

s.each_line(' is ') {|line| p line }

Output:

"This is "
"the first line.\nThis is "
"line two.\n\nThis is "
"line four.\nThis is "
"line five.\n"

With chomp as true, removes the trailing line_sep from each line:

s.each_line(chomp: true) {|line| p line }

Output:

"This is the first line."
"This is line two."
""
"This is line four."
"This is line five."

With an empty string as line_sep, forms and passes “paragraphs” by splitting at each occurrence of two or more newlines:

s.each_line('') {|line| p line }

Output:

"This is the first line.\nThis is line two.\n\n"
"This is line four.\nThis is line five.\n"

With no block given, returns an enumerator.

String#each_codepoint

Calls the given block with each successive codepoint from self; each codepoint is the integer value for a character; returns self:

'hello'.each_codepoint {|codepoint| print codepoint, ' ' }
print "\n"
'тест'.each_codepoint {|codepoint| print codepoint, ' ' }
print "\n"
'こんにちは'.each_codepoint {|codepoint| print codepoint, ' ' }
print "\n"

Output:

104 101 108 108 111
1090 1077 1089 1090
12371 12435 12395 12385 12399

Returns an enumerator if no block is given.

String#force_encoding

Changes the encoding of self to encoding, which may be a string encoding name or an Encoding object; returns self:

s = 'łał'
s.bytes                   # => [197, 130, 97, 197, 130]
s.encoding                # => #<Encoding:UTF-8>
s.force_encoding('ascii') # => "\xC5\x82a\xC5\x82"
s.encoding                # => #<Encoding:US-ASCII>

Does not change the underlying bytes:

s.bytes                   # => [197, 130, 97, 197, 130]

Makes the change even if the given encoding is invalid for self (as is the change above):

s.valid_encoding?                 # => false
s.force_encoding(Encoding::UTF_8) # => "łał"
s.valid_encoding?                 # => true

String#valid_encoding?

Returns true if self is encoded correctly, false otherwise:

"\xc2\xa1".force_encoding("UTF-8").valid_encoding? # => true
"\xc2".force_encoding("UTF-8").valid_encoding?     # => false
"\x80".force_encoding("UTF-8").valid_encoding?     # => false

String#unicode_normalize

Returns a copy of self with Unicode normalization applied.

Argument form must be one of the following symbols (see Unicode normalization forms):

:nfc: Canonical decomposition, followed by canonical composition.
:nfd: Canonical decomposition.
:nfkc: Compatibility decomposition, followed by canonical composition.
:nfkd: Compatibility decomposition.

The encoding of self must be one of:

Encoding::UTF_8
Encoding::UTF_16BE
Encoding::UTF_16LE
Encoding::UTF_32BE
Encoding::UTF_32LE
Encoding::GB18030
Encoding::UCS_2BE
Encoding::UCS_4BE

Examples:

"a\u0300".unicode_normalize      # => "a"
"\u00E0".unicode_normalize(:nfd) # => "a "

String#unicode_normalize!

Like String#unicode_normalize, except that the normalization is performed on self.

Related String#unicode_normalized?.

String#unicode_normalized?

Returns true if self is in the given form of Unicode normalization, false otherwise. The form must be one of :nfc, :nfd, :nfkc, or :nfkd.

Examples:

"a\u0300".unicode_normalized?       # => false
"a\u0300".unicode_normalized?(:nfd) # => true
"\u00E0".unicode_normalized?        # => true
"\u00E0".unicode_normalized?(:nfd)  # => false

Raises an exception if self is not in a Unicode encoding:

s = "\xE0".force_encoding('ISO-8859-1')
s.unicode_normalized? # Raises Encoding::CompatibilityError.

Float#to_int

Returns self truncated to an Integer.

1.2.to_i    # => 1
(-1.2).to_i # => -1

Note that the limited precision of floating-point arithmetic may lead to surprising results:

(0.3 / 0.1).to_i  # => 2 (!)

Encoding::default_internal

Returns default internal encoding. Strings will be transcoded to the default internal encoding in the following places if the default internal encoding is not nil:

CSV
Etc.sysconfdir and Etc.systmpdir
File data read from disk
File names from Dir
Integer#chr
String#inspect and Regexp#inspect
Strings returned from Readline
Strings returned from SDBM
Time#zone
Values from ENV
Values in ARGV including $PROGRAM_NAME

Additionally String#encode and String#encode! use the default internal encoding if no encoding is given.

The script encoding (__ENCODING__), not default_internal, is used as the encoding of created strings.

Encoding::default_internal is initialized with -E option or nil otherwise.

Sets default internal encoding or removes default internal encoding when passed nil. You should not set Encoding::default_internal in ruby code as strings created before changing the value may have a different encoding from strings created after the change. Instead you should use ruby -E to invoke ruby with the correct default_internal.

See Encoding::default_internal for information on how the default internal encoding is used.

Encoding::locale_charmap

Returns the locale charmap name. It returns nil if no appropriate information.

Debian GNU/Linux
  LANG=C
    Encoding.locale_charmap  #=> "ANSI_X3.4-1968"
  LANG=ja_JP.EUC-JP
    Encoding.locale_charmap  #=> "EUC-JP"

SunOS 5
  LANG=C
    Encoding.locale_charmap  #=> "646"
  LANG=ja
    Encoding.locale_charmap  #=> "eucJP"

The result is highly platform dependent. So Encoding.find(Encoding.locale_charmap) may cause an error. If you need some encoding object even for unknown locale, Encoding.find(“locale”) can be used.

Enumerator#with_index

Iterates the given block for each element with an index, which starts from offset. If no block is given, returns a new Enumerator that includes the index, starting from offset

offset: the starting index to use

Object#singleton_class

Returns the singleton class of obj. This method creates a new singleton class if obj does not have one.

If obj is nil, true, or false, it returns NilClass, TrueClass, or FalseClass, respectively. If obj is an Integer, a Float or a Symbol, it raises a TypeError.

Object.new.singleton_class  #=> #<Class:#<Object:0xb7ce1e24>>
String.singleton_class      #=> #<Class:String>
nil.singleton_class         #=> NilClass

Object#singleton_methods

Returns an array of the names of singleton methods for obj. If the optional all parameter is true, the list will include methods in modules included in obj. Only public and protected singleton methods are returned.

module Other
  def three() end
end

class Single
  def Single.four() end
end

a = Single.new

def a.one()
end

class << a
  include Other
  def two()
  end
end

Single.singleton_methods    #=> [:four]
a.singleton_methods(false)  #=> [:two, :one]
a.singleton_methods         #=> [:two, :one, :three]

Object#instance_variables

Returns an array of instance variable names for the receiver. Note that simply defining an accessor does not create the corresponding instance variable.

class Fred
  attr_accessor :a1
  def initialize
    @iv = 3
  end
end
Fred.new.instance_variables   #=> [:@iv]

Object#instance_of?

Returns true if obj is an instance of the given class. See also Object#kind_of?.

class A;     end
class B < A; end
class C < B; end

b = B.new
b.instance_of? A   #=> false
b.instance_of? B   #=> true
b.instance_of? C   #=> false

Object#kind_of?

Returns true if class is the class of obj, or if class is one of the superclasses of obj or modules included in obj.

module M;    end
class A
  include M
end
class B < A; end
class C < B; end

b = B.new
b.is_a? A          #=> true
b.is_a? B          #=> true
b.is_a? C          #=> false
b.is_a? M          #=> true

b.kind_of? A       #=> true
b.kind_of? B       #=> true
b.kind_of? C       #=> false
b.kind_of? M       #=> true

Object#singleton_method

Similar to method, searches singleton method only.

class Demo
  def initialize(n)
    @iv = n
  end
  def hello()
    "Hello, @iv = #{@iv}"
  end
end

k = Demo.new(99)
def k.hi
  "Hi, @iv = #{@iv}"
end
m = k.singleton_method(:hi)
m.call   #=> "Hi, @iv = 99"
m = k.singleton_method(:hello) #=> NameError

Results for: "minmax"

Array#each_index

Array#repeated_combination

Array#bsearch_index

Integer#to_int

Refinement#refined_class

Numeric#to_int

String#initialize_copy

String#each_line

String#each_codepoint

String#force_encoding

String#valid_encoding?

String#unicode_normalize

String#unicode_normalize!

String#unicode_normalized?

Float#to_int

Encoding::default_internal

Encoding::default_internal=

Encoding::locale_charmap

Enumerator#with_index

Object#singleton_class

Object#singleton_methods

Object#instance_variables

Object#instance_of?

Object#kind_of?

Object#singleton_method