Package org.microproxy.starlark.stdlib

Class RandomModule

java.lang.Object
org.microproxy.starlark.stdlib.RandomModule
All Implemented Interfaces:
org.microproxy.thirdparty.starlark.eval.StarlarkValue
public final class RandomModule extends Object implements org.microproxy.thirdparty.starlark.eval.StarlarkValue
@stdlib//jrandom: randomness from SecureRandom, for random.star and uuid.star (starlarky's came from BouncyCastle's registrar). There is no seeding: every value is unpredictable, like Python's random.SystemRandom.

  • Method Summary

    Modifier and Type
    Method
    Description
    Object
    choice(org.microproxy.thirdparty.starlark.eval.Sequence<?> seq)
    Selects an element uniformly from a non-empty sequence.
    org.microproxy.thirdparty.starlark.eval.StarlarkInt
    getrandbits(org.microproxy.thirdparty.starlark.eval.StarlarkInt k)
    Produces a non-negative integer with at most the requested number of bits.
    org.microproxy.thirdparty.starlark.eval.StarlarkBytes
    randbytes(org.microproxy.thirdparty.starlark.eval.StarlarkInt n)
    Produces random bytes using the same generator as urandom(org.microproxy.thirdparty.starlark.eval.StarlarkInt).
    org.microproxy.thirdparty.starlark.eval.StarlarkInt
    randint(org.microproxy.thirdparty.starlark.eval.StarlarkInt a, org.microproxy.thirdparty.starlark.eval.StarlarkInt b)
    Chooses an integer uniformly between inclusive endpoints.
    org.microproxy.thirdparty.starlark.eval.StarlarkFloat
    random()
    Produces a uniformly distributed random fraction.
    org.microproxy.thirdparty.starlark.eval.StarlarkInt
    randrange(org.microproxy.thirdparty.starlark.eval.StarlarkInt start, Object stop, org.microproxy.thirdparty.starlark.eval.StarlarkInt step)
    Chooses an integer uniformly from a stepped, stop-exclusive range.
    org.microproxy.thirdparty.starlark.eval.StarlarkList<?>
    sample(org.microproxy.thirdparty.starlark.eval.Sequence<?> population, org.microproxy.thirdparty.starlark.eval.StarlarkInt k, org.microproxy.thirdparty.starlark.eval.StarlarkThread thread)
    Samples sequence positions without replacement.
    void
    shuffle(org.microproxy.thirdparty.starlark.eval.StarlarkList<?> x)
    Randomly permutes a mutable list in place.
    org.microproxy.thirdparty.starlark.eval.StarlarkFloat
    uniform(Object a, Object b)
    Interpolates between two numeric endpoints using a random fraction.
    org.microproxy.thirdparty.starlark.eval.StarlarkBytes
    urandom(org.microproxy.thirdparty.starlark.eval.StarlarkInt n)
    Produces cryptographically strong random bytes.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    Methods inherited from interface org.microproxy.thirdparty.starlark.eval.StarlarkValue

    checkHashable, debugPrint, getStarlarkType, isAcyclic, isImmutable, repr, str, truth

  • Method Details

    • urandom

      public org.microproxy.thirdparty.starlark.eval.StarlarkBytes urandom(org.microproxy.thirdparty.starlark.eval.StarlarkInt n) throws org.microproxy.thirdparty.starlark.eval.EvalException
      Produces cryptographically strong random bytes.
      Parameters:
      n - the number of bytes, from zero through 16 MiB
      Returns:
      immutable random bytes
      Throws:
      org.microproxy.thirdparty.starlark.eval.EvalException - if the byte count is negative or exceeds the limit

    • randbytes

      public org.microproxy.thirdparty.starlark.eval.StarlarkBytes randbytes(org.microproxy.thirdparty.starlark.eval.StarlarkInt n) throws org.microproxy.thirdparty.starlark.eval.EvalException
      Produces random bytes using the same generator as urandom(org.microproxy.thirdparty.starlark.eval.StarlarkInt).
      Parameters:
      n - the number of bytes, from zero through 16 MiB
      Returns:
      immutable random bytes
      Throws:
      org.microproxy.thirdparty.starlark.eval.EvalException - if the byte count is negative or exceeds the limit

    • getrandbits

      public org.microproxy.thirdparty.starlark.eval.StarlarkInt getrandbits(org.microproxy.thirdparty.starlark.eval.StarlarkInt k) throws org.microproxy.thirdparty.starlark.eval.EvalException
      Produces a non-negative integer with at most the requested number of bits.
      Parameters:
      k - the number of random bits, from zero through 134,217,728 bits
      Returns:
      an integer sampled uniformly from [0, 2**k)
      Throws:
      org.microproxy.thirdparty.starlark.eval.EvalException - if the bit count is negative or exceeds the limit

    • randrange

      public org.microproxy.thirdparty.starlark.eval.StarlarkInt randrange(org.microproxy.thirdparty.starlark.eval.StarlarkInt start, Object stop, org.microproxy.thirdparty.starlark.eval.StarlarkInt step) throws org.microproxy.thirdparty.starlark.eval.EvalException
      Chooses an integer uniformly from a stepped, stop-exclusive range.
      Parameters:
      start - the first value, or the stop value when stop is None
      stop - the exclusive endpoint, or None for a range starting at zero
      step - the nonzero difference between successive values
      Returns:
      a randomly selected range member
      Throws:
      org.microproxy.thirdparty.starlark.eval.EvalException - if the step is zero or the range is empty

    • randint

      public org.microproxy.thirdparty.starlark.eval.StarlarkInt randint(org.microproxy.thirdparty.starlark.eval.StarlarkInt a, org.microproxy.thirdparty.starlark.eval.StarlarkInt b) throws org.microproxy.thirdparty.starlark.eval.EvalException
      Chooses an integer uniformly between inclusive endpoints.
      Parameters:
      a - the inclusive lower endpoint
      b - the inclusive upper endpoint
      Returns:
      a randomly selected integer from a through b
      Throws:
      org.microproxy.thirdparty.starlark.eval.EvalException - if b is less than a

    • random

      public org.microproxy.thirdparty.starlark.eval.StarlarkFloat random()
      Produces a uniformly distributed random fraction.
      Returns:
      a random float in [0.0, 1.0)

    • uniform

      public org.microproxy.thirdparty.starlark.eval.StarlarkFloat uniform(Object a, Object b) throws org.microproxy.thirdparty.starlark.eval.EvalException
      Interpolates between two numeric endpoints using a random fraction.
      Parameters:
      a - the first integer or float endpoint
      b - the second integer or float endpoint
      Returns:
      a randomly interpolated float
      Throws:
      org.microproxy.thirdparty.starlark.eval.EvalException - if an endpoint is not a supported number

    • choice

      public Object choice(org.microproxy.thirdparty.starlark.eval.Sequence<?> seq) throws org.microproxy.thirdparty.starlark.eval.EvalException
      Selects an element uniformly from a non-empty sequence.
      Parameters:
      seq - the sequence to choose from
      Returns:
      one of the sequence elements
      Throws:
      org.microproxy.thirdparty.starlark.eval.EvalException - if the sequence is empty

    • shuffle

      public void shuffle(org.microproxy.thirdparty.starlark.eval.StarlarkList<?> x) throws org.microproxy.thirdparty.starlark.eval.EvalException
      Randomly permutes a mutable list in place.
      Parameters:
      x - the list to reorder
      Throws:
      org.microproxy.thirdparty.starlark.eval.EvalException - if the list cannot be mutated

    • sample

      public org.microproxy.thirdparty.starlark.eval.StarlarkList<?> sample(org.microproxy.thirdparty.starlark.eval.Sequence<?> population, org.microproxy.thirdparty.starlark.eval.StarlarkInt k, org.microproxy.thirdparty.starlark.eval.StarlarkThread thread) throws org.microproxy.thirdparty.starlark.eval.EvalException
      Samples sequence positions without replacement.
      Parameters:
      population - the source sequence; repeated values remain distinct positions
      k - the number of positions to choose
      thread - the calling thread that owns the result list
      Returns:
      a list of the selected elements in sampling order
      Throws:
      org.microproxy.thirdparty.starlark.eval.EvalException - if k is negative, too large or not representable as an int