Random::Formatter#choose generates a string that randomly draws from a source array of characters.
The argument source specifies the array of characters from which to generate the string. The argument n specifies the length, in characters, of the string to be generated.
The result may contain whatever characters are in the source array.
require 'random/formatter' prng.choose([*'l'..'r'], 16) #=> "lmrqpoonmmlqlron" prng.choose([*'0'..'9'], 5) #=> "27309"
Simple deprecation method that deprecates name by wrapping it up in a dummy method. It warns on each call to the dummy method telling the user of repl (unless repl is :none) and the year/month that it is planned to go away.
A Zlib::Inflate#inflate wrapper
Iterates over array indexes.
When a block given, passes each successive array index to the block; returns self:
a = [:foo, 'bar', 2] a.each_index {|index| puts "#{index} #{a[index]}" }
Output:
0 foo 1 bar 2 2
Allows the array to be modified during iteration:
a = [:foo, 'bar', 2] a.each_index {|index| puts index; a.clear if index > 0 }
Output:
0 1
When no block given, returns a new Enumerator:
a = [:foo, 'bar', 2] e = a.each_index e # => #<Enumerator: [:foo, "bar", 2]:each_index> a1 = e.each {|index| puts "#{index} #{a[index]}"}
Output:
0 foo 1 bar 2 2
Related: each, reverse_each.
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.
Returns a new Array whose elements are the elements of self at the given Integer or Range indexes.
For each positive index, returns the element at offset index:
a = [:foo, 'bar', 2] a.values_at(0, 2) # => [:foo, 2] a.values_at(0..1) # => [:foo, "bar"]
The given indexes may be in any order, and may repeat:
a = [:foo, 'bar', 2] a.values_at(2, 0, 1, 0, 2) # => [2, :foo, "bar", :foo, 2] a.values_at(1, 0..2) # => ["bar", :foo, "bar", 2]
Assigns nil for an index that is too large:
a = [:foo, 'bar', 2] a.values_at(0, 3, 1, 3) # => [:foo, nil, "bar", nil]
Returns a new empty Array if no arguments given.
For each negative index, counts backward from the end of the array:
a = [:foo, 'bar', 2] a.values_at(-1, -3) # => [2, :foo]
Assigns nil for an index that is too small:
a = [:foo, 'bar', 2] a.values_at(0, -5, 1, -6, 2) # => [:foo, nil, "bar", nil, 2]
The given indexes may have a mixture of signs:
a = [:foo, 'bar', 2] a.values_at(0, -2, 1, -1) # => [:foo, "bar", "bar", 2]
Deletes an element from self, per the given Integer index.
When index is non-negative, deletes the element at offset index:
a = [:foo, 'bar', 2] a.delete_at(1) # => "bar" a # => [:foo, 2]
If index is too large, returns nil.
When index is negative, counts backward from the end of the array:
a = [:foo, 'bar', 2] a.delete_at(-2) # => "bar" a # => [:foo, 2]
If index is too small (far from zero), returns nil.
Searches self as described at method bsearch, but returns the index of the found element instead of the element itself.
Returns the list of private methods accessible to obj. If the all parameter is set to false, only those methods in the receiver will be listed.
Splits str using the supplied parameter as the record separator ($/ by default), passing each substring in turn to the supplied block. If a zero-length record separator is supplied, the string is split into paragraphs delimited by multiple successive newlines.
If chomp is true, separator will be removed from the end of each line.
If no block is given, an enumerator is returned instead.
"hello\nworld".each_line {|s| p s} # prints: # "hello\n" # "world" "hello\nworld".each_line('l') {|s| p s} # prints: # "hel" # "l" # "o\nworl" # "d" "hello\n\n\nworld".each_line('') {|s| p s} # prints # "hello\n\n" # "world" "hello\nworld".each_line(chomp: true) {|s| p s} # prints: # "hello" # "world" "hello\nworld".each_line('l', chomp: true) {|s| p s} # prints: # "he" # "" # "o\nwor" # "d"
Passes each byte in str to the given block, or returns an enumerator if no block is given.
"hello".each_byte {|c| print c, ' ' }
produces:
104 101 108 108 111
Passes the Integer ordinal of each character in str, also known as a codepoint when applied to Unicode strings to the given block. For encodings other than UTF-8/UTF-16(BE|LE)/UTF-32(BE|LE), values are directly derived from the binary representation of each character.
If no block is given, an enumerator is returned instead.
"hello\u0639".each_codepoint {|c| print c, ' ' }
produces:
104 101 108 108 111 1593
Unicode Normalization—Returns a normalized form of str, using Unicode normalizations NFC, NFD, NFKC, or NFKD. The normalization form used is determined by form, which can be any of the four values :nfc, :nfd, :nfkc, or :nfkd. The default is :nfc.
If the string is not in a Unicode Encoding, then an Exception is raised. In this context, ‘Unicode Encoding’ means any of UTF-8, UTF-16BE/LE, and UTF-32BE/LE, as well as GB18030, UCS_2BE, and UCS_4BE. Anything other than UTF-8 is implemented by converting to UTF-8, which makes it slower than UTF-8.
"a\u0300".unicode_normalize #=> "\u00E0" "a\u0300".unicode_normalize(:nfc) #=> "\u00E0" "\u00E0".unicode_normalize(:nfd) #=> "a\u0300" "\xE0".force_encoding('ISO-8859-1').unicode_normalize(:nfd) #=> Encoding::CompatibilityError raised
Destructive version of String#unicode_normalize, doing Unicode normalization in place.
Checks whether str is in Unicode normalization form form, which can be any of the four values :nfc, :nfd, :nfkc, or :nfkd. The default is :nfc.
If the string is not in a Unicode Encoding, then an Exception is raised. For details, see String#unicode_normalize.
"a\u0300".unicode_normalized? #=> false "a\u0300".unicode_normalized?(:nfd) #=> true "\u00E0".unicode_normalized? #=> true "\u00E0".unicode_normalized?(:nfd) #=> false "\xE0".force_encoding('ISO-8859-1').unicode_normalized? #=> Encoding::CompatibilityError raised
Returns the next-larger representable Float.
These examples show the internally stored values (64-bit hexadecimal) for each Float f and for the corresponding f.next_float:
f = 0.0 # 0x0000000000000000 f.next_float # 0x0000000000000001 f = 0.01 # 0x3f847ae147ae147b f.next_float # 0x3f847ae147ae147c
In the remaining examples here, the output is shown in the usual way (result to_s):
0.01.next_float # => 0.010000000000000002 1.0.next_float # => 1.0000000000000002 100.0.next_float # => 100.00000000000001 f = 0.01 (0..3).each_with_index {|i| printf "%2d %-20a %s\n", i, f, f.to_s; f = f.next_float }
Output:
0 0x1.47ae147ae147bp-7 0.01
1 0x1.47ae147ae147cp-7 0.010000000000000002
2 0x1.47ae147ae147dp-7 0.010000000000000004
3 0x1.47ae147ae147ep-7 0.010000000000000005
f = 0.0; 100.times { f += 0.1 }
f # => 9.99999999999998 # should be 10.0 in the ideal world.
10-f # => 1.9539925233402755e-14 # the floating point error.
10.0.next_float-10 # => 1.7763568394002505e-15 # 1 ulp (unit in the last place).
(10-f)/(10.0.next_float-10) # => 11.0 # the error is 11 ulp.
(10-f)/(10*Float::EPSILON) # => 8.8 # approximation of the above.
"%a" % 10 # => "0x1.4p+3"
"%a" % f # => "0x1.3fffffffffff5p+3" # the last hex digit is 5. 16 - 5 = 11 ulp.
Related: Float#prev_float
Returns the next-smaller representable Float.
These examples show the internally stored values (64-bit hexadecimal) for each Float f and for the corresponding f.pev_float:
f = 5e-324 # 0x0000000000000001 f.prev_float # 0x0000000000000000 f = 0.01 # 0x3f847ae147ae147b f.prev_float # 0x3f847ae147ae147a
In the remaining examples here, the output is shown in the usual way (result to_s):
0.01.prev_float # => 0.009999999999999998 1.0.prev_float # => 0.9999999999999999 100.0.prev_float # => 99.99999999999999 f = 0.01 (0..3).each_with_index {|i| printf "%2d %-20a %s\n", i, f, f.to_s; f = f.prev_float }
Output:
0 0x1.47ae147ae147bp-7 0.01 1 0x1.47ae147ae147ap-7 0.009999999999999998 2 0x1.47ae147ae1479p-7 0.009999999999999997 3 0x1.47ae147ae1478p-7 0.009999999999999995
Related: Float#next_float.
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
Sets the Fiber scheduler for the current thread. If the scheduler is set, non-blocking fibers (created by Fiber.new with blocking: false, or by Fiber.schedule) call that scheduler’s hook methods on potentially blocking operations, and the current thread will call scheduler’s close method on finalization (allowing the scheduler to properly manage all non-finished fibers).
scheduler can be an object of any class corresponding to Fiber::SchedulerInterface. Its implementation is up to the user.
See also the “Non-blocking fibers” section in class docs.
Returns the Fiber scheduler, that was last set for the current thread with Fiber.set_scheduler if and only if the current fiber is non-blocking.