diff options
| -rw-r--r-- | stdlib/random.ml | 23 |
1 files changed, 11 insertions, 12 deletions
diff --git a/stdlib/random.ml b/stdlib/random.ml index a3300ad4a..7a228eece 100644 --- a/stdlib/random.ml +++ b/stdlib/random.ml @@ -32,14 +32,14 @@ let state = [| 440266690 |] -let j = ref 0 +let index = ref 0 (* Returns 30 random bits as an integer 0 <= x < 1073741824 *) let bits () = - j := (!j + 1) mod 55; + index := (!index + 1) mod 55; let newval = - Array.unsafe_get state ((!j+24) mod 55) + Array.unsafe_get state !j in - Array.unsafe_set state !j newval; + state.((!index + 24) mod 55) + state.(!index) in + state.(!index) <- newval; newval land 0x3FFFFFFF (* Returns a float 0 <= x < 1 with at most 90 bits of precision. *) @@ -73,17 +73,16 @@ let init seed = lxor (Char.code d.[3] lsl 22) in for i = 0 to 54 do - Array.unsafe_set state i (mdg ()) + state.(i) <- (mdg ()) done; - j := 0 + index := 0 (* Full initialisation. The seed is an array of integers. *) let full_init seed = init 27182818; for i = 0 to Array.length (seed) - 1 do let j = i mod 55 in - Array.unsafe_set state j - (Array.unsafe_get state j + Array.unsafe_get seed i) + state.(j) <- state.(j) + seed.(i) done (* Low-entropy system-dependent initialisation. *) @@ -95,13 +94,13 @@ let self_init () = init (random_seed());; (* Manipulating the current state. *) -type state = { state_array : int array; j : int };; +type state = { st : int array; idx : int };; -let get_state () = { state_array = state; j = !j };; +let get_state () = { st = Array.copy state; idx = !index };; let set_state s = - Array.blit s.state_array 0 state 0 (Array.length state); - j := s.j; + Array.blit s.st 0 state 0 55; + index := s.idx; ;; (******************** |