Parse a YAML string in yaml
. Returns the Psych::Nodes::Document
. filename
is used in the exception message if a Psych::SyntaxError
is raised.
Raises a Psych::SyntaxError
when a YAML syntax error is detected.
Example:
Psych.parse("---\n - a\n - b") # => #<Psych::Nodes::Document:0x00> begin Psych.parse("--- `", "file.txt") rescue Psych::SyntaxError => ex ex.file # => 'file.txt' ex.message # => "(file.txt): found character that cannot start any token" end
See Psych::Nodes
for more information about YAML AST.
Returns a default parser
Spawns the specified command on a newly allocated pty. You can also use the alias ::getpty
.
The command’s controlling tty is set to the slave device of the pty and its standard input/output/error is redirected to the slave device.
command
and command_line
are the full commands to run, given a String. Any additional arguments
will be passed to the command.
In the non-block form this returns an array of size three, [r, w, pid]
.
In the block form these same values will be yielded to the block:
Compresses the given string
. Valid values of level are Zlib::NO_COMPRESSION
, Zlib::BEST_SPEED
, Zlib::BEST_COMPRESSION
, Zlib::DEFAULT_COMPRESSION
, or an integer from 0 to 9.
This method is almost equivalent to the following code:
def deflate(string, level) z = Zlib::Deflate.new(level) dst = z.deflate(string, Zlib::FINISH) z.close dst end
See also Zlib.inflate
Decompresses string
. Raises a Zlib::NeedDict
exception if a preset dictionary is needed for decompression.
This method is almost equivalent to the following code:
def inflate(string) zstream = Zlib::Inflate.new buf = zstream.inflate(string) zstream.finish zstream.close buf end
See also Zlib.deflate
Enables garbage collection, returning true
if garbage collection was previously disabled.
GC.disable #=> false GC.enable #=> true GC.enable #=> false
Returns a Hash
containing information about the GC
.
The hash includes information about internal statistics about GC
such as:
{ :count=>0, :heap_allocated_pages=>24, :heap_sorted_length=>24, :heap_allocatable_pages=>0, :heap_available_slots=>9783, :heap_live_slots=>7713, :heap_free_slots=>2070, :heap_final_slots=>0, :heap_marked_slots=>0, :heap_eden_pages=>24, :heap_tomb_pages=>0, :total_allocated_pages=>24, :total_freed_pages=>0, :total_allocated_objects=>7796, :total_freed_objects=>83, :malloc_increase_bytes=>2389312, :malloc_increase_bytes_limit=>16777216, :minor_gc_count=>0, :major_gc_count=>0, :remembered_wb_unprotected_objects=>0, :remembered_wb_unprotected_objects_limit=>0, :old_objects=>0, :old_objects_limit=>0, :oldmalloc_increase_bytes=>2389760, :oldmalloc_increase_bytes_limit=>16777216 }
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 time used to execute the given block as a Benchmark::Tms
object. Takes label
option.
require 'benchmark' n = 1000000 time = Benchmark.measure do n.times { a = "1" } end puts time
Generates:
0.220000 0.000000 0.220000 ( 0.227313)
Returns the elapsed real time used to execute the given block.
Returns the time used to execute the given block as a Benchmark::Tms
object. Takes label
option.
require 'benchmark' n = 1000000 time = Benchmark.measure do n.times { a = "1" } end puts time
Generates:
0.220000 0.000000 0.220000 ( 0.227313)
Returns the elapsed real time used to execute the given block.
Returns the arc tangent of z
CMath.atan(1 + 1i) #=> (1.0172219678978514+0.4023594781085251i)
returns the arc tangent of y
divided by x
using the signs of y
and x
to determine the quadrant
CMath.atan2(1 + 1i, 0) #=> (1.5707963267948966+0.0i)
returns the inverse hyperbolic tangent of z
CMath.atanh(1 + 1i) #=> (0.4023594781085251+1.0172219678978514i)
Returns the arc tangent of z
CMath.atan(1 + 1i) #=> (1.0172219678978514+0.4023594781085251i)
returns the arc tangent of y
divided by x
using the signs of y
and x
to determine the quadrant
CMath.atan2(1 + 1i, 0) #=> (1.5707963267948966+0.0i)
returns the inverse hyperbolic tangent of z
CMath.atanh(1 + 1i) #=> (0.4023594781085251+1.0172219678978514i)
Get the thread of the primary server.
This returns nil if there is no primary server. See primary_server
.
Get the thread of the primary server.
This returns nil if there is no primary server. See primary_server
.
Returns true if new
is newer than all old_list
. Non-existent files are older than any file.
FileUtils.uptodate?('hello.o', %w(hello.c hello.h)) or \ system 'make hello.o'
Returns true if new
is newer than all old_list
. Non-existent files are older than any file.
FileUtils.uptodate?('hello.o', %w(hello.c hello.h)) or \ system 'make hello.o'
Computes the arc tangent given y
and x
. Returns a Float
in the range -PI..PI. Return value is a angle in radians between the positive x-axis of cartesian plane and the point given by the coordinates (x
, y
) on it.
Domain: (-INFINITY, INFINITY)
Codomain: [-PI, PI]
Math.atan2(-0.0, -1.0) #=> -3.141592653589793 Math.atan2(-1.0, -1.0) #=> -2.356194490192345 Math.atan2(-1.0, 0.0) #=> -1.5707963267948966 Math.atan2(-1.0, 1.0) #=> -0.7853981633974483 Math.atan2(-0.0, 1.0) #=> -0.0 Math.atan2(0.0, 1.0) #=> 0.0 Math.atan2(1.0, 1.0) #=> 0.7853981633974483 Math.atan2(1.0, 0.0) #=> 1.5707963267948966 Math.atan2(1.0, -1.0) #=> 2.356194490192345 Math.atan2(0.0, -1.0) #=> 3.141592653589793 Math.atan2(INFINITY, INFINITY) #=> 0.7853981633974483 Math.atan2(INFINITY, -INFINITY) #=> 2.356194490192345 Math.atan2(-INFINITY, INFINITY) #=> -0.7853981633974483 Math.atan2(-INFINITY, -INFINITY) #=> -2.356194490192345
Computes the arc tangent of x
. Returns -PI/2..PI/2.
Domain: (-INFINITY, INFINITY)
Codomain: (-PI/2, PI/2)
Math.atan(0) #=> 0.0