cl-rng/README

Functions:
  chance (fraction-chance ...)
   Returns T if the chance was met, NIL if not.

  weighted (weights &key (default nil) ...)
   Takes a list in this format:
	((value-one . 0.25)
	 (value-two . 0.50)
	 (value-three . 0.25))
   And calculates the result as chances. The values of the alist should total 1, if they are less than one and the chance is not met, return `default`.

  shuffle! (sequence ...)
   Shuffle a sequence in place.
   Returns the sequence.

  within (sequence ...)
   Returns a random element in this sequence.

  within-set (sequence value)
   Set a random element in `sequence` to `value`.
   Can be used like: (setf (within seq) value)
  
  range (start end &key (integral nil) ...)
   Returns a random number in the inclusive range of `start` to `end`.
   If `integral` is not NIL, round to an integer.

All the above functions (except within-set() can take the key parameter `provider`, which defaults to cl-rng:*default-randomness-provider*.

Parameters:

  *default-precision*
   The default precision of the default randomness provider. Defaults to 1.

  *default-randomness-provider*
   The default `provider` for the above functions. Should be a function with a lambda list that resembles those of `urandom` and `crandom` functions. Defaults to cl-rng:crandom

Module `urandom`:

  urandom (&key (limit 1.0) (precision 1) (transform nil))
   Get a random value from /dev/urandom, between 0 and 1 inclusive `precision` times. Multiply its average by `limit`, and transform it by `transform` (if `transform` is not NIL) and return.

  urandom-range (range &key (limit 1.0) (precision 1) (transform nil))
   Apply `urandom` function to a sequence in place.

  urandom-bytes (len &key (transform #'identity) (type :vector))
   Get `len` bytes from /dev/urandom and return them as a vector if type is :VECTOR, otherwise a list. Apply `transform` to each element.

Module `crandom` (requires FFI):

  crandom (&key (limit 1.0) (precision 1) (transform #'identity))
   Get a cryptographically secure random floating point number (64 bit) between 0 and 1 from FFI `precision` times, multiply its average by `limit`, apply `transform` to it and return. If FFI fails, return NIL.

  crandom-range (range &key (limit 1.0) (precision 1) (transform #'identity))
   Apply `crandom` to a sequence in place.

  crandom-bytes (len &key (transform #'identity) (type :vector))
   Get `len` cryptographically secure bytes from FFI, apply `transform` to each, collect to vector if type is :VECTOR, list otherwise.
   If FFI fails, return NIL.

----

To use crandom, run sudo make install. (installs to /usr/local/lib and /usr/lib)

Prebuilt binary signed with https://flanchan.moe/flanchan.asc (b1e9dd6730c1307edf0104f1822aac1801a37028f2af8d2b8446eb7cfc4ec34a)

To build dependencies yourself run:
 make build && sudo make install
(requires Rust)