Parses the most indented lines into blocks that are marked and added to the frontier
If object is an Array object, returns object.
Otherwise if object responds to :to_ary, calls object.to_ary and returns the result.
Returns nil if object does not respond to :to_ary
Raises an exception unless object.to_ary returns an Array object.
Replaces the content of self with the content of other_array; returns self:
a = [:foo, 'bar', 2] a.replace(['foo', :bar, 3]) # => ["foo", :bar, 3]
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.
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]]
Searches self as described at method bsearch, but returns the index of the found element instead of the element itself.
If object is an Integer object, returns object.
Integer.try_convert(1) # => 1
Otherwise if object responds to :to_int, calls object.to_int and returns the result.
Integer.try_convert(1.25) # => 1
Returns nil if object does not respond to :to_int
Integer.try_convert([]) # => nil
Raises an exception unless object.to_int returns an Integer object.
Returns the number of bits of the value of self, which is the bit position of the highest-order bit that is different from the sign bit (where the least significant bit has bit position 1). If there is no such bit (zero or minus one), returns zero.
This method returns ceil(log2(self < 0 ? -self : self + 1))>.
(-2**1000-1).bit_length # => 1001 (-2**1000).bit_length # => 1000 (-2**1000+1).bit_length # => 1000 (-2**12-1).bit_length # => 13 (-2**12).bit_length # => 12 (-2**12+1).bit_length # => 12 -0x101.bit_length # => 9 -0x100.bit_length # => 8 -0xff.bit_length # => 8 -2.bit_length # => 1 -1.bit_length # => 0 0.bit_length # => 0 1.bit_length # => 1 0xff.bit_length # => 8 0x100.bit_length # => 9 (2**12-1).bit_length # => 12 (2**12).bit_length # => 13 (2**12+1).bit_length # => 13 (2**1000-1).bit_length # => 1000 (2**1000).bit_length # => 1001 (2**1000+1).bit_length # => 1001
For Integer n, this method can be used to detect overflow in Array#pack:
if n.bit_length < 32 [n].pack('l') # No overflow. else raise 'Overflow' end
Returns self (which is already an Integer).
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)
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 (!)
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 true if the named file is writable by the real user and group id of this process. See access(3).
Note that some OS-level security features may cause this to return true even though the file is not writable by the real user/group.
If file_name is writable by others, returns an integer representing the file permission bits of file_name. Returns nil otherwise. The meaning of the bits is platform dependent; on Unix systems, see stat(2).
file_name can be an IO object.
File.world_writable?("/tmp") #=> 511 m = File.world_writable?("/tmp") sprintf("%o", m) #=> "777"
Returns the list of available encoding names.
Encoding.name_list
#=> ["US-ASCII", "ASCII-8BIT", "UTF-8",
"ISO-8859-1", "Shift_JIS", "EUC-JP",
"Windows-31J",
"BINARY", "CP932", "eucJP"]
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:
File data read from disk
Strings returned from Readline
Strings returned from SDBM
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.
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
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.
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
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().
Sets the backtrace information associated with exc. The backtrace must be an array of String objects or a single String in the format described in Exception#backtrace.
Return a list of the local variable names defined where this NameError exception was raised.
Internal use only.
Return true if the caused method was called as private.