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ANSI Common Lisp 12 Numbers 12.2 Dictionary of Numbers
12.2.43 *random-state* |
Variable |
- Value Type:
-
a random state.
- Initial Value:
-
implementation-dependent.
- Description:
-
The current random state, which is used, for example,
by the function random when a random state is not explicitly supplied.
- Examples:
-
(random-state-p *random-state*) true
(setq snap-shot (make-random-state))
;; The series from any given point is random,
;; but if you backtrack to that point, you get the same series.
(list (loop for i from 1 to 10 collect (random))
(let ((*random-state* snap-shot))
(loop for i from 1 to 10 collect (random)))
(loop for i from 1 to 10 collect (random))
(let ((*random-state* snap-shot))
(loop for i from 1 to 10 collect (random))))
((19 16 44 19 96 15 76 96 13 61)
(19 16 44 19 96 15 76 96 13 61)
(16 67 0 43 70 79 58 5 63 50)
(16 67 0 43 70 79 58 5 63 50))
- Affected By:
-
The implementation.
random.
- See Also:
-
make-random-state,
random,
random-state
- Notes:
-
Binding *random-state* to a different
random state object correctly saves and
restores the old random state object.
- Allegro CL Implementation Details:
-
None.
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