* random.c: Improve documentation of Random. Patch by Gregory

Parkhurst.  [Ruby 1.9 - Bug #5410]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@33413 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
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drbrain 2011-10-05 23:54:33 +00:00
Родитель 2e35340cf6
Коммит f365f19054
2 изменённых файлов: 134 добавлений и 72 удалений

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@ -1,3 +1,8 @@
Thu Oct 6 08:54:05 2011 Eric Hodel <drbrain@segment7.net>
* random.c: Improve documentation of Random. Patch by Gregory
Parkhurst. [Ruby 1.9 - Bug #5410]
Thu Oct 6 01:44:51 2011 CHIKANAGA Tomoyuki <nagachika00@gmail.com>
* cont.c (cont_mark): mark original Thread object from saved_thread.

201
random.c
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@ -450,20 +450,14 @@ rand_init(struct MT *mt, VALUE vseed)
}
/*
* call-seq: Random.new([seed]) -> prng
* call-seq:
* Random.new() -> prng
* Random.new(seed) -> prng
*
* Creates new Mersenne Twister based pseudorandom number generator with
* seed. When the argument seed is omitted, the generator is initialized
* with Random.new_seed.
* Creates a new PRNG using +seed+ to set the initial state. If +seed+ is
* omitted, the generator is initialized with Random.new_seed.
*
* The argument seed is used to ensure repeatable sequences of random numbers
* between different runs of the program.
*
* prng = Random.new(1234)
* [ prng.rand, prng.rand ] #=> [0.191519450378892, 0.622108771039832]
* [ prng.integer(10), prng.integer(1000) ] #=> [4, 664]
* prng = Random.new(1234)
* [ prng.rand, prng.rand ] #=> [0.191519450378892, 0.622108771039832]
* See Random.srand for more information on the use of seed values.
*/
static VALUE
random_init(int argc, VALUE *argv, VALUE obj)
@ -569,7 +563,10 @@ make_seed_value(const void *ptr)
/*
* call-seq: Random.new_seed -> integer
*
* Returns arbitrary value for seed.
* Returns an arbitrary seed value. This is used by Random.new
* when no seed value is specified as an argument.
*
* Random.new_seed #=> 115032730400174366788466674494640623225
*/
static VALUE
random_seed(void)
@ -582,7 +579,16 @@ random_seed(void)
/*
* call-seq: prng.seed -> integer
*
* Returns the seed of the generator.
* Returns the seed value used to initialize the generator. This may be used to
* initialize another generator with the same state at a later time, causing it
* to produce the same sequence of numbers.
*
* prng1 = Random.new(1234)
* prng1.seed #=> 1234
* prng1.rand(100) #=> 47
*
* prng2 = Random.new(prng1.seed)
* prng2.rand(100) #=> 47
*/
static VALUE
random_get_seed(VALUE obj)
@ -758,17 +764,26 @@ random_load(VALUE obj, VALUE dump)
}
/*
* call-seq:
* srand(number=0) -> old_seed
* call-seq:
* srand(number=0) -> old_seed
*
* Seeds the pseudorandom number generator to the value of
* <i>number</i>. If <i>number</i> is omitted,
* seeds the generator using a combination of the time, the
* process id, and a sequence number. (This is also the behavior if
* <code>Kernel::rand</code> is called without previously calling
* <code>srand</code>, but without the sequence.) By setting the seed
* to a known value, scripts can be made deterministic during testing.
* The previous seed value is returned. Also see <code>Kernel::rand</code>.
* Seeds the system pseudo-random number generator, Random::DEFAULT, with
* +number+. The previous seed value is returned.
*
* If +number+ is omitted, seeds the generator using a source of entropy
* provided by the operating system, if available (/dev/urandom on Unix systems
* or the RSA cryptographic provider on Windows), which is then combined with
* the time, the process id, and a sequence number.
*
* srand may be used to ensure repeatable sequences of pseudo-random numbers
* between different runs of the program. By setting the seed to a known value,
* programs can be made deterministic during testing.
*
* srand 1234 # => 268519324636777531569100071560086917274
* [ rand, rand ] # => [0.1915194503788923, 0.6221087710398319]
* [ rand(10), rand(1000) ] # => [4, 664]
* srand 1234 # => 1234
* [ rand, rand ] # => [0.1915194503788923, 0.6221087710398319]
*/
static VALUE
@ -878,9 +893,9 @@ limited_big_rand(struct MT *mt, struct RBignum *limit)
}
/*
* Returns random unsigned long value in [0, _limit_].
* Returns random unsigned long value in [0, +limit+].
*
* Note that _limit_ is included, and the range of the argument and the
* Note that +limit+ is included, and the range of the argument and the
* return value depends on environments.
*/
unsigned long
@ -924,8 +939,10 @@ rb_random_real(VALUE obj)
/*
* call-seq: prng.bytes(size) -> a_string
*
* Returns a random binary string. The argument size specified the length of
* the result string.
* Returns a random binary string containing +size+ bytes.
*
* random_string = Random.new.bytes(10) # => "\xD7:R\xAB?\x83\xCE\xFAkO"
* random_string.size # => 10
*/
static VALUE
random_bytes(VALUE obj, VALUE len)
@ -1111,27 +1128,32 @@ rand_range(struct MT* mt, VALUE range)
/*
* call-seq:
* prng.rand -> float
* prng.rand(limit) -> number
* prng.rand -> float
* prng.rand(max) -> number
*
* When the argument is an +Integer+ or a +Bignum+, it returns a
* random integer greater than or equal to zero and less than the
* argument. Unlike Random.rand, when the argument is a negative
* integer or zero, it raises an ArgumentError.
* When +max+ is an Integer, +rand+ returns a random integer greater than
* or equal to zero and less than +max+. Unlike Kernel.rand, when +max+
* is a negative integer or zero, +rand+ raises an ArgumentError.
*
* When the argument is a +Float+, it returns a random floating point
* number between 0.0 and _max_, including 0.0 and excluding _max_.
* prng = Random.new
* prng.rand(100) # => 42
*
* When the argument _limit_ is a +Range+, it returns a random
* number where range.member?(number) == true.
* prng.rand(5..9) #=> one of [5, 6, 7, 8, 9]
* prng.rand(5...9) #=> one of [5, 6, 7, 8]
* prng.rand(5.0..9.0) #=> between 5.0 and 9.0, including 9.0
* prng.rand(5.0...9.0) #=> between 5.0 and 9.0, excluding 9.0
* When +max+ is a Float, +rand+ returns a random floating point number
* between 0.0 and +max+, including 0.0 and excluding +max+.
*
* +begin+/+end+ of the range have to have subtract and add methods.
* prng.rand(1.5) # => 1.4600282860034115
*
* Otherwise, it raises an ArgumentError.
* When +max+ is a Range, +rand+ returns a random number where
* range.member?(number) == true.
*
* prng.rand(5..9) # => one of [5, 6, 7, 8, 9]
* prng.rand(5...9) # => one of [5, 6, 7, 8]
* prng.rand(5.0..9.0) # => between 5.0 and 9.0, including 9.0
* prng.rand(5.0...9.0) # => between 5.0 and 9.0, excluding 9.0
*
* Both the beginning and ending values of the range must respond to subtract
* (<tt>-</tt>) and add (<tt>+</tt>)methods, or rand will raise an
* ArgumentError.
*/
static VALUE
random_rand(int argc, VALUE *argv, VALUE obj)
@ -1177,9 +1199,27 @@ random_rand(int argc, VALUE *argv, VALUE obj)
/*
* call-seq:
* prng1 == prng2 -> true or false
* prng1 == prng2 -> true or false
*
* Returns true if the generators' states equal.
* Returns true if the two generators have the same internal state, otherwise
* false. Equivalent generators will return the same sequence of
* pseudo-random numbers. Two generators will generally have the same state
* only if they were initialized with the same seed
*
* Random.new == Random.new # => false
* Random.new(1234) == Random.new(1234) # => true
*
* and have the same invocation history.
*
* prng1 = Random.new(1234)
* prng2 = Random.new(1234)
* prng1 == prng2 # => true
*
* prng1.rand # => 0.1915194503788923
* prng1 == prng2 # => false
*
* prng2.rand # => 0.1915194503788923
* prng1 == prng2 # => true
*/
static VALUE
random_equal(VALUE self, VALUE other)
@ -1196,31 +1236,32 @@ random_equal(VALUE self, VALUE other)
}
/*
* call-seq:
* rand(max=0) -> number
* call-seq:
* rand(max=0) -> number
*
* If called without an argument, or if <tt>max.to_i.abs == 0</tt>, rand
* returns a pseudo-random floating point number between 0.0 and 1.0,
* including 0.0 and excluding 1.0.
*
* If <i>max</i> is +Range+, returns a pseudorandom number where
* range.member(number) == true.
* rand #=> 0.2725926052826416
*
* Or else converts _max_ to an integer using max1 =
* max<code>.to_i.abs</code>.
* When <tt>max.abs</tt> is greater than or equal to 1, +rand+ returns a
* pseudo-random integer greater than or equal to 0 and less than
* <tt>max.to_i.abs</tt>.
*
* Then if _max_ is +nil+ the result is zero, returns a pseudorandom floating
* point number greater than or equal to 0.0 and less than 1.0.
* rand(100) #=> 12
*
* Otherwise, returns a pseudorandom integer greater than or equal to zero and
* less than max1.
* Negative or floating point values for +max+ are allowed, but may give
* surprising results.
*
* <code>Kernel::srand</code> may be used to ensure repeatable sequences of
* random numbers between different runs of the program. Ruby currently uses
* a modified Mersenne Twister with a period of 2**19937-1.
* rand(-100) # => 87
* rand(-0.5) # => 0.8130921818028143
* rand(1.9) # equivalent to rand(1), which is always 0
*
* srand 1234 #=> 0
* [ rand, rand ] #=> [0.191519450163469, 0.49766366626136]
* [ rand(10), rand(1000) ] #=> [6, 817]
* srand 1234 #=> 1234
* [ rand, rand ] #=> [0.191519450163469, 0.49766366626136]
* Kernel.srand may be used to ensure that sequences of random numbers are
* reproducible between different runs of a program.
*
* See also Random.rand.
*/
static VALUE
@ -1244,12 +1285,11 @@ rb_f_rand(int argc, VALUE *argv, VALUE obj)
}
/*
* call-seq:
* Random.rand -> float
* Random.rand(limit) -> number
*
* Alias of _Random::DEFAULT.rand_.
* call-seq:
* Random.rand -> float
* Random.rand(max) -> number
*
* Alias of Random::DEFAULT.rand.
*/
static VALUE
@ -1322,10 +1362,27 @@ rb_reset_random_seed(void)
}
/*
* Document-class: Random
* Document-class: Random
*
* The Random module contains module functions for producing pseudo-random
* numbers that meet certain requirements for randomness.
* Random provides an interface to Ruby's pseudo-random number generator, or
* PRNG. The PRNG produces a deterministic sequence of bits which approximate
* true randomness. The sequence may be represented by integers, floats, or
* binary strings.
*
* The generator may be initialized with either a system-generated or
* user-supplied seed value by using Random.srand.
*
* The class method Random.rand provides the base functionality of Kernel.rand
* along with better handling of floating point values. These are both
* interfaces to Random::DEFAULT, the Ruby system PRNG.
*
* Random.new will create a new PRNG with a state independent of
* Random::DEFAULT, allowing multiple generators with different seed values or
* sequence positions to exist simultaneously. Random objects can be
* marshaled, allowing sequences to be saved and resumed.
*
* PRNGs are currently implemented as a modified Mersenne Twister with a period
* of 2**19937-1.
*/
void