Returns a new Array
containing the first n
element of self
, where n
is a non-negative Integer
; does not modify self
.
Examples:
a = [0, 1, 2, 3, 4, 5] a.take(1) # => [0] a.take(2) # => [0, 1] a.take(50) # => [0, 1, 2, 3, 4, 5] a # => [0, 1, 2, 3, 4, 5]
Builds a command line string from an argument list array
joining all elements escaped for the Bourne shell and separated by a space.
See Shellwords.shelljoin
for details.
Returns a Hash
containing implementation-dependent counters inside the VM.
This hash includes information about method/constant caches:
{ :constant_cache_invalidations=>2, :constant_cache_misses=>14, :global_cvar_state=>27 }
If USE_DEBUG_COUNTER
is enabled, debug counters will be included.
The contents of the hash are implementation specific and may be changed in the future.
This method is only expected to work on C Ruby.
Returns the value as a rational. The optional argument eps
is always ignored.
Return the class or module refined by the receiver.
module M refine String do end end M.refinements[0].target # => String
Returns a new Complex object formed from the arguments, each of which must be an instance of Numeric
, or an instance of one of its subclasses: Complex, Float
, Integer
, Rational
; see Rectangular Coordinates:
Complex.rect(3) # => (3+0i) Complex.rect(3, Math::PI) # => (3+3.141592653589793i) Complex.rect(-3, -Math::PI) # => (-3-3.141592653589793i)
Complex.rectangular is an alias for Complex.rect.
Returns the real value for self
:
Complex.rect(7).real # => 7 Complex.rect(9, -4).real # => 9
If self
was created with polar coordinates, the returned value is computed, and may be inexact:
Complex.polar(1, Math::PI/4).real # => 0.7071067811865476 # Square root of 2.
Returns the array [self.real, self.imag]
:
Complex.rect(1, 2).rect # => [1, 2]
If self
was created with polar coordinates, the returned value is computed, and may be inexact:
Complex.polar(1.0, 1.0).rect # => [0.5403023058681398, 0.8414709848078965]
Complex#rectangular
is an alias for Complex#rect
.
Returns false
; for compatibility with Numeric#real?
.
Returns a Rational
object whose value is exactly or approximately equivalent to that of self.real
.
With no argument epsilon
given, returns a Rational object whose value is exactly equal to that of self.real.rationalize
:
Complex.rect(1, 0).rationalize # => (1/1) Complex.rect(1, Rational(0, 1)).rationalize # => (1/1) Complex.rect(3.14159, 0).rationalize # => (314159/100000)
With argument epsilon
given, returns a Rational object whose value is exactly or approximately equal to that of self.real
to the given precision:
Complex.rect(3.14159, 0).rationalize(0.1) # => (16/5) Complex.rect(3.14159, 0).rationalize(0.01) # => (22/7) Complex.rect(3.14159, 0).rationalize(0.001) # => (201/64) Complex.rect(3.14159, 0).rationalize(0.0001) # => (333/106) Complex.rect(3.14159, 0).rationalize(0.00001) # => (355/113) Complex.rect(3.14159, 0).rationalize(0.000001) # => (7433/2366) Complex.rect(3.14159, 0).rationalize(0.0000001) # => (9208/2931) Complex.rect(3.14159, 0).rationalize(0.00000001) # => (47460/15107) Complex.rect(3.14159, 0).rationalize(0.000000001) # => (76149/24239) Complex.rect(3.14159, 0).rationalize(0.0000000001) # => (314159/100000) Complex.rect(3.14159, 0).rationalize(0.0) # => (3537115888337719/1125899906842624)
Related: Complex#to_r
.
Returns zero as a Rational:
nil.rationalize # => (0/1)
Argument eps
is ignored.
Returns array [self, 0]
.
Returns true
if self
is a real number (i.e. not Complex
).
Returns self
.
Splits str
into an array of tokens in the same way the UNIX Bourne shell does.
See Shellwords.shellsplit
for details.
Escapes str
so that it can be safely used in a Bourne shell command line.
See Shellwords.shellescape
for details.
Returns a simpler approximation of the value (flt-|eps| <= result <= flt+|eps|). If the optional argument eps
is not given, it will be chosen automatically.
0.3.rationalize #=> (3/10) 1.333.rationalize #=> (1333/1000) 1.333.rationalize(0.01) #=> (4/3)
See also Float#to_r
.
Terminates the fiber by raising an uncatchable exception. It only terminates the given fiber and no other fiber, returning nil
to another fiber if that fiber was calling resume
or transfer
.
Fiber#kill
only interrupts another fiber when it is in Fiber.yield
. If called on the current fiber then it raises that exception at the Fiber#kill
call site.
If the fiber has not been started, transition directly to the terminated state.
If the fiber is already terminated, does nothing.
Raises FiberError
if called on a fiber belonging to another thread.
Returns true if the fiber can still be resumed (or transferred to). After finishing execution of the fiber block this method will always return false
.
Returns the current position of self
; see Dir As Stream-Like:
dir = Dir.new('example') dir.tell # => 0 dir.read # => "." dir.tell # => 1
Returns a File::Stat
object for the file at filepath
(see File::Stat
):
File.stat('t.txt').class # => File::Stat
Like File::stat
, but does not follow the last symbolic link; instead, returns a File::Stat
object for the link itself.
File.symlink('t.txt', 'symlink') File.stat('symlink').size # => 47 File.lstat('symlink').size # => 5
Returns the real (absolute) pathname of pathname in the actual filesystem not containing symlinks or useless dots.
If dir_string is given, it is used as a base directory for interpreting relative pathname instead of the current directory.
All components of the pathname must exist when this method is called.
Returns the real (absolute) pathname of pathname in the actual filesystem. The real pathname doesn’t contain symlinks or useless dots.
If dir_string is given, it is used as a base directory for interpreting relative pathname instead of the current directory.
The last component of the real pathname can be nonexistent.
Like File#stat
, but does not follow the last symbolic link; instead, returns a File::Stat
object for the link itself:
File.symlink('t.txt', 'symlink') f = File.new('symlink') f.stat.size # => 47 f.lstat.size # => 11