factor/basis/random/random-docs.factor

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USING: help.markup help.syntax math kernel sequences ;
IN: random
HELP: seed-random
{ $values { "tuple" "a random number generator" } { "seed" "an integer between 0 and 2^32-1" } }
{ $description "Seed the random number generator." }
{ $notes "Not supported on all random number generators." } ;
HELP: random-32*
{ $values { "tuple" "a random number generator" } { "r" "an integer between 0 and 2^32-1" } }
{ $description "Generates a random 32-bit unsigned integer." } ;
HELP: random-bytes*
{ $values { "n" "an integer" } { "tuple" "a random number generator" } { "byte-array" "a sequence of random bytes" } }
{ $description "Generates a byte-array of random bytes." } ;
HELP: random
{ $values { "seq" sequence } { "elt" "a random element" } }
{ $description "Outputs a random element of the input sequence. Outputs " { $link f } " if the sequence is empty." }
{ $notes "Since integers are sequences, passing an integer " { $snippet "n" } " outputs an integer in the interval " { $snippet "[0,n)" } "." }
{ $examples
{ $unchecked-example "USING: random prettyprint ;"
"10 random ."
"3" }
{ $unchecked-example "USING: random prettyprint ;"
"SYMBOL: heads"
"SYMBOL: tails"
"{ heads tails } random ."
"heads" }
} ;
HELP: random-bytes
{ $values { "n" "an integer" } { "byte-array" "a random integer" } }
{ $description "Outputs an integer with n bytes worth of bits." }
{ $examples
{ $unchecked-example "USING: prettyprint random ;"
"5 random-bytes ."
"B{ 135 50 185 119 240 }"
}
} ;
HELP: random-bits
{ $values { "n" "an integer" } { "r" "a random integer" } }
{ $description "Outputs an random integer n bits in length." } ;
HELP: with-random
{ $values { "tuple" "a random generator" } { "quot" "a quotation" } }
{ $description "Calls the quotation with the random generator in a dynamic variable. All random numbers will be generated using this random generator." } ;
HELP: with-secure-random
{ $values { "quot" "a quotation" } }
{ $description "Calls the quotation with the secure random generator in a dynamic variable. All random numbers will be generated using this random generator." } ;
HELP: with-system-random
{ $values { "quot" "a quotation" } }
{ $description "Calls the quotation with the system's random generator in a dynamic variable. All random numbers will be generated using this random generator." } ;
{ with-random with-secure-random with-system-random } related-words
HELP: randomize
{ $values
{ "seq" sequence }
{ "seq" sequence }
}
{ $description "Randomizes a sequence in-place with the Fisher-Yates algorithm and returns the sequence." } ;
HELP: delete-random
{ $values
{ "seq" sequence }
{ "elt" object } }
{ $description "Deletes a random number from a sequence using " { $link delete-nth } " and returns the deleted object." } ;
ARTICLE: "random-protocol" "Random protocol"
"A random number generator must implement one of these two words:"
{ $subsection random-32* }
{ $subsection random-bytes* }
"Optional, to seed a random number generator:"
{ $subsection seed-random } ;
ARTICLE: "random" "Generating random integers"
"The " { $vocab-link "random" } " vocabulary contains a protocol for generating random or pseudorandom numbers."
$nl
"The “Mersenne Twister” pseudorandom number generator algorithm is the default generator stored in " { $link random-generator } "."
$nl
"Generate a random object:"
{ $subsection random }
"Combinators to change the random number generator:"
{ $subsection with-random }
{ $subsection with-system-random }
{ $subsection with-secure-random }
"Implementation:"
{ $subsection "random-protocol" }
"Randomizing a sequence:"
{ $subsection randomize }
"Deleting a random element from a sequence:"
{ $subsection delete-random } ;
ABOUT: "random"