Module random

Nim's standard random number generator. Based on the xoroshiro128+ (xor/rotate/shift/rotate) library.

• More information: http://xoroshiro.di.unimi.it/
• C implementation: http://xoroshiro.di.unimi.it/xoroshiro128plus.c

Do not use this module for cryptographic purposes!

Imports

times

Types

Rand = object
  a0, a1: ui

State of the random number generator. The procs that use the default state are not thread-safe!

Procs

proc next(r: var Rand): uint64 {...}{.raises: [], tags: [].}

Uses the state to compute a new uint64 random number.

proc skipRandomNumbers(s: var Rand) {...}{.raises: [], tags: [].}

This is the jump function for the generator. It is equivalent to 2^64 calls to next(); it can be used to generate 2^64 non-overlapping subsequences for parallel computations.

proc random(max: int): int {...}{.gcsafe, locks: 0, deprecated, raises: [], tags: [].}

Returns a random number in the range 0..max-1. The sequence of random number is always the same, unless randomize is called which initializes the random number generator with a "random" number, i.e. a tickcount. Deprecated since version 0.18.0. Use rand instead.

proc random(max: float): float {...}{.gcsafe, locks: 0, deprecated, raises: [], tags: [].}

Returns a random number in the range 0..<max. The sequence of random number is always the same, unless randomize is called which initializes the random number generator with a "random" number, i.e. a tickcount. Deprecated since version 0.18.0. Use rand instead.

proc random[T](x: HSlice[T, T]): T {...}{.deprecated.}

For a slice a .. b returns a value in the range a .. b-1. Deprecated since version 0.18.0. Use rand instead.

proc random[T](a: openArray[T]): T {...}{.deprecated.}

returns a random element from the openarray a. Deprecated since version 0.18.0. Use rand instead.

proc rand(r: var Rand; max: Natural): int {...}{.gcsafe, locks: 0, raises: [], tags: [].}

Returns a random number in the range 0..max. The sequence of random number is always the same, unless randomize is called which initializes the random number generator with a "random" number, i.e. a tickcount.

proc rand(max: int): int {...}{.gcsafe, locks: 0, raises: [], tags: [].}

Returns a random number in the range 0..max. The sequence of random number is always the same, unless randomize is called which initializes the random number generator with a "random" number, i.e. a tickcount.

proc rand(r: var Rand; max: range[0.0 .. high(float)]): float {...}{.gcsafe, locks: 0,
    raises: [], tags: [].}

Returns a random number in the range 0..max. The sequence of random number is always the same, unless randomize is called which initializes the random number generator with a "random" number, i.e. a tickcount.

proc rand(max: float): float {...}{.gcsafe, locks: 0, raises: [], tags: [].}

Returns a random number in the range 0..max. The sequence of random number is always the same, unless randomize is called which initializes the random number generator with a "random" number, i.e. a tickcount.

proc rand[T](r: var Rand; x: HSlice[T, T]): T

For a slice a .. b returns a value in the range a .. b.

proc rand[T](x: HSlice[T, T]): T

For a slice a .. b returns a value in the range a .. b.

proc rand[T](r: var Rand; a: openArray[T]): T

returns a random element from the openarray a.

proc rand[T](a: openArray[T]): T

returns a random element from the openarray a.

proc initRand(seed: int64): Rand {...}{.raises: [], tags: [].}

Creates a new Rand state from seed.

proc randomize(seed: int64) {...}{.gcsafe, locks: 0, raises: [], tags: [].}

Initializes the default random number generator with a specific seed.

proc shuffle[T](r: var Rand; x: var openArray[T])

Swaps the positions of elements in a sequence randomly.

proc shuffle[T](x: var openArray[T])

Swaps the positions of elements in a sequence randomly.

proc randomize() {...}{.gcsafe, locks: 0, raises: [], tags: [TimeEffect].}

Initializes the random number generator with a "random" number, i.e. a tickcount. Note: Does not work for NimScript.