state—a random state, or nil
, or t
.
The default is nil
.
new-state—a random state object.
Creates a fresh object of type random-state
suitable
for use as the value of *random-state*
.
If state is a random state object,
the new-state is a copy5 of that object.
If state is nil
,
the new-state is a copy5 of the current random state.
If state is t
,
the new-state is a fresh random state object
that has been randomly initialized by some means.
(let* ((rs1 (make-random-state nil))
(rs2 (make-random-state t))
(rs3 (make-random-state rs2))
(rs4 nil))
(list (loop for i from 1 to 10
collect (random 100)
when (= i 5)
do (setq rs4 (make-random-state)))
(loop for i from 1 to 10 collect (random 100 rs1))
(loop for i from 1 to 10 collect (random 100 rs2))
(loop for i from 1 to 10 collect (random 100 rs3))
(loop for i from 1 to 10 collect (random 100 rs4))))
→ ((29 25 72 57 55 68 24 35 54 65)
(29 25 72 57 55 68 24 35 54 65)
(93 85 53 99 58 62 2 23 23 59)
(93 85 53 99 58 62 2 23 23 59)
(68 24 35 54 65 54 55 50 59 49))
Should signal an error of type type-error
if state is not a random state, or nil
, or t
.
One important use of make-random-state
is to allow the same
series of pseudo-random numbers to be generated many times within a
single program.