With a block given, calls the block with each repeated permutation of length size of the elements of self; each permutation is an array; returns self. The order of the permutations is indeterminate.

If a positive integer argument size is given, calls the block with each size-tuple repeated permutation of the elements of self. The number of permutations is self.size**size.

Examples:

size is 1:

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

size is 2:

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

If size is zero, calls the block once with an empty array.

If size is negative, does not call the block:

[0, 1, 2].repeated_permutation(-1) {|permutation| fail 'Cannot happen' }

With no block given, returns a new Enumerator.

Related: see Methods for Combining.

Array#repeated_combination

With a block given, calls the block with each repeated combination of length size of the elements of self; each combination is an array; returns self. The order of the combinations is indeterminate.

If a positive integer argument size is given, calls the block with each size-tuple repeated combination of the elements of self. The number of combinations is (size+1)(size+2)/2.

Examples:

size is 1:

c = []
[0, 1, 2].repeated_combination(1) {|combination| c.push(combination) }
c # => [[0], [1], [2]]

size is 2:

c = []
[0, 1, 2].repeated_combination(2) {|combination| c.push(combination) }
c # => [[0, 0], [0, 1], [0, 2], [1, 1], [1, 2], [2, 2]]

If size is zero, calls the block once with an empty array.

If size is negative, does not call the block:

[0, 1, 2].repeated_combination(-1) {|combination| fail 'Cannot happen' }

With no block given, returns a new Enumerator.

Related: see Methods for Combining.

Array#fetch_values

With no block given, returns a new array containing the elements of self at the offsets specified by indexes. Each of the indexes must be an integer-convertible object:

a = [:foo, :bar, :baz]
a.fetch_values(2, 0)   # => [:baz, :foo]
a.fetch_values(2.1, 0) # => [:baz, :foo]
a.fetch_values         # => []

For a negative index, counts backwards from the end of the array:

a.fetch_values(-2, -1) # [:bar, :baz]

When no block is given, raises an exception if any index is out of range.

With a block given, for each index:

If the index is in range, uses an element of self (as above).
Otherwise, calls the block with the index and uses the block’s return value.

Example:

a = [:foo, :bar, :baz]
a.fetch_values(1, 0, 42, 777) { |index| index.to_s }
# => [:bar, :foo, "42", "777"]

Related: see Methods for Fetching.

String#each_char

Calls the given block with each successive character from self; returns self:

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

Output:

h e l l o
т е с т
こ ん に ち は

Returns an enumerator if no block is given.

Dir::each_child

Like Dir.foreach, except that entries '.' and '..' are not included.

Dir#each_child

Calls the block with each entry name in self except '.' and '..':

dir = Dir.new('/example')
dir.each_child {|entry_name| p entry_name }

Output:

"config.h"
"lib"
"main.rb"

If no block is given, returns an enumerator.

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.

IO#each_char

Calls the given block with each character in the stream; returns self. See Character IO.

f = File.new('t.rus')
a = []
f.each_char {|c| a << c.ord }
a # => [1090, 1077, 1089, 1090]
f.close

Returns an Enumerator if no block is given.