Returns zero.
Returns 0 if the value is positive, pi otherwise.
Returns an array; [num, 0].
Returns true if num is a finite number, otherwise returns false.
Returns num truncated (toward zero) to a precision of ndigits decimal digits (default: 0).
Numeric implements this by converting its value to a Float and invoking Float#truncate.
Invokes the given block with the sequence of numbers starting at num, incremented by step (defaulted to 1) on each call.
The loop finishes when the value to be passed to the block is greater than limit (if step is positive) or less than limit (if step is negative), where limit is defaulted to infinity.
In the recommended keyword argument style, either or both of step and limit (default infinity) can be omitted. In the fixed position argument style, zero as a step (i.e. num.step(limit, 0)) is not allowed for historical compatibility reasons.
If all the arguments are integers, the loop operates using an integer counter.
If any of the arguments are floating point numbers, all are converted to floats, and the loop is executed floor(n + n*Float::EPSILON) + 1 times, where n = (limit - num)/step.
Otherwise, the loop starts at num, uses either the less-than (<) or greater-than (>) operator to compare the counter against limit, and increments itself using the + operator.
If no block is given, an Enumerator is returned instead. Especially, the enumerator is an Enumerator::ArithmeticSequence if both limit and step are kind of Numeric or nil.
For example:
p 1.step.take(4) p 10.step(by: -1).take(4) 3.step(to: 5) {|i| print i, " " } 1.step(10, 2) {|i| print i, " " } Math::E.step(to: Math::PI, by: 0.2) {|f| print f, " " }
Will produce:
[1, 2, 3, 4] [10, 9, 8, 7] 3 4 5 1 3 5 7 9 2.718281828459045 2.9182818284590453 3.118281828459045
Returns the denominator (always positive).
Returns 0 if the value is positive, pi otherwise.
Returns float truncated (toward zero) to a precision of ndigits decimal digits (default: 0).
When the precision is negative, the returned value is an integer with at least ndigits.abs trailing zeros.
Returns a floating point number when ndigits is positive, otherwise returns an integer.
2.8.truncate #=> 2 (-2.8).truncate #=> -2 1.234567.truncate(2) #=> 1.23 34567.89.truncate(-2) #=> 34500
Note that the limited precision of floating point arithmetic might lead to surprising results:
(0.3 / 0.1).truncate #=> 2 (!)
Returns true if float is a valid IEEE floating point number, i.e. it is not infinite and Float#nan? is false.
Returns a string containing a representation of self. As well as a fixed or exponential form of the float, the call may return NaN, Infinity, and -Infinity.
Returns the denominator (always positive). The result is machine dependent.
See also Float#numerator.
Transfer control to another fiber, resuming it from where it last stopped or starting it if it was not resumed before. The calling fiber will be suspended much like in a call to Fiber.yield. You need to require 'fiber' before using this method.
The fiber which receives the transfer call is treats it much like a resume call. Arguments passed to transfer are treated like those passed to resume.
You cannot resume a fiber that transferred control to another one. This will cause a double resume error. You need to transfer control back to this fiber before it can yield and resume.
Example:
fiber1 = Fiber.new do puts "In Fiber 1" Fiber.yield end fiber2 = Fiber.new do puts "In Fiber 2" fiber1.transfer puts "Never see this message" end fiber3 = Fiber.new do puts "In Fiber 3" end fiber2.resume fiber3.resume
produces
In fiber 2 In fiber 1 In fiber 3
Returns fiber information string.
Return a string describing this Dir object.
Repositions dir to the first entry.
d = Dir.new("testdir") d.read #=> "." d.rewind #=> #<Dir:0x401b3fb0> d.read #=> "."
Deletes the named directory. Raises a subclass of SystemCallError if the directory isn’t empty.
Returns true if the named file is a directory, false otherwise.
Deprecated method. Don’t use.
Returns a File::Stat object for the named file (see File::Stat).
File.stat("testfile").mtime #=> Tue Apr 08 12:58:04 CDT 2003
Same as File::stat, but does not follow the last symbolic link. Instead, reports on the link itself.
File.symlink("testfile", "link2test") #=> 0 File.stat("testfile").size #=> 66 File.lstat("link2test").size #=> 8 File.stat("link2test").size #=> 66
Creates a new name for an existing file using a hard link. Will not overwrite new_name if it already exists (raising a subclass of SystemCallError). Not available on all platforms.
File.link("testfile", ".testfile") #=> 0 IO.readlines(".testfile")[0] #=> "This is line one\n"
Creates a symbolic link called new_name for the existing file old_name. Raises a NotImplemented exception on platforms that do not support symbolic links.
File.symlink("testfile", "link2test") #=> 0